Temperature effects on hyphal growth of wood-decay basidiomycetes isolated from Pinus densiflora deadwood

Hyphal growth rates were tested on malt extract agar plates at eight different temperatures (5–40?°C) using 36 isolates of 17 basidiomycete species obtained from Pinus densiflora deadwood in Japan. All isolates of four brown rot species showed optimum growth at 30?°C, whereas the optimum growth temperature of white rot species varied from 20?°C to 30?°C. Analysis using a dataset from four cooler sites showed that brown rot fungi grew more rapidly than white rot fungi at higher temperatures (25?°C, 30?°C, and 35?°C). These results suggest that the hyphal growth of brown rot fungi might be physiologically adapted to higher temperatures than those of white rot fungi among the fungal species inhabiting deadwood of P. densiflora in Japan.     

Influence of mediopreoptic stimulation on temperature regulation in rats before and after serotonin injection]

The effects of electrical stimulation of the Area praceoptica medialis (APM) and intraventricular serotonine injection were investigated in thirty Wistar rats tested under normo-, hypo- and hyperthermic conditions. Temperature responses such as oxygen consumption and rectal temperature were measured and heat loss was calculated. The effects of the first stimulation before serotonine injection were compared with those of the second one after serotonine application in order to prove the influence of serotonine on temperature responses due to APM stimulation. On the other hand, the influence of stimulation on changes produced by serotonine injection should be shown by the recordings of the second serotonine responses with stimulation effects and by comparison of these with those of the first serotonine responses without stimulation effects. The first APM stimulation depending on the rectal temperature before stimulation resulted in decreasing oxygen consumption in hypothermic rats while increasing that of hyperthermic animals. There was a little decrease of rectal temperature under hyper- and normothermic conditions. while under hypothermic conditions animals showed marked depression. The increase in heat loss, however, was least in hyperthermic rats and most pronounced in hypothermic animals. The second APM stimulation did almost not affect the temperature responses after serotonine application in normothermic rats, while causing supercooling agin under hypothermic conditions and insignificant cooling at hyperthermic environment temperature. Comparison of the first and second stimulation effects revealed statistical significant differences at normo-, hypo- and hyperthermic temperatures. The results are discussed under consideration of the different starting conditions before the first and second stimulation. These findings do not indicate that serotonine would shift the sensibility of mediopraeoptic structures and thus unequivocally modifies stimulation effects.     

Aspen wood-wool is preferred as a resting place, but does not affect intracage fighting of male BALB/c and C57BL/6J mice

Aspen wood-wool, provided as nesting material, was evaluated as a possible improvement of cage environment for 10-14-week-old inbred male mice maintained in groups of six (BALB/c n = 72 and C57BL/6J n = 36). The daily behaviour of mice was video recorded and their body weight, food consumption, weights of some organs and serum corticosterone concentrations were measured. Aggressive interactions between cage mates and against a strange intruder as well as the number of wounds on the back of the animals was monitored in order to evaluate the effect of nesting material on intermale aggression. Nesting material did not affect the daily active/passive behaviour patterns of mice, although animals clearly preferred it as a resting place. BALB/c mice given nesting material showed less weight gain and smaller brown adipose tissue weights than animals without nesting material. The other characteristics measured were not affected by the presence of nesting material in either strain. The presence of nesting material had no effect on fighting in cages. C57BL/6J mice were more aggressive than BALB/c mice according to the number of wounded animals in a cage. Wounded BALB/c mice had enlarged spleens and decreased epididymal adipose tissue weights. In conclusion, the nesting material used in this study did not adversely affect the animals. On the other hand, the material was clearly preferred to conventional bedding as a resting place. These findings suggest that nesting material may improve the cage environment of laboratory mice. Furthermore, there was an indication of strain differences in aggressive behaviour. It could be suggested that C57BL/6J mice are less tolerant towards intruders and housing six mice per cage is not suitable for this strain.     

MATERNAL PROCESSES IN THE COLD-ADAPTATION OF MICE

• 1 Both laboratory and wild house mice, Mus musculus, given bedding, can breed in captivity in an environment kept at – 3°C. The nest temperature when a young litter is present then fluctuates widely. In a typical laboratory (at 21°C) the temperature of the nest is both higher and more constant.
• 2 The ovaries of pregnant mice breeding at – 3°C have more corpora lute a than controls at 21°C. This is not an index of a higher ovulation rate, but is evidently due to the presence of corpora lutea from a pievious ovulation.
• 3 In the absence of concurrent lactation, weights and numbers of foetuses at the sixteenth day of gestation are little affected by cold; but in both environments foetal weight diminishes with increasing size of litter. This is a systemic effect: foetal weight is hardly if at all influenced by the number of other foetuses in the same uterine horn.
• 4 Cold delays the onset of breeding and lengthens the interval between litters. Mean litter sizes are usually lower than in the warm environment, mainly through absence of large litters.
• 5 The body weights of laboratory mice are usually lower at – 3°C than 21°C at all ages from 3 weeks. This does not, however, apply to strain C57BL, which never stores much fat in adipose tissue. Wild mice bred at – 3°C are heavier than controls at 21°C, possibly because only the heavier individuals survive in early life.
• 6 F ₁ hybrids produced by crossing two inbred strains breed better and more consistently than the parent strains at both temperatures; but the effect of heterozygosis is much greater in the cold environment.
• 7 Food intake changes little during pregnancy, but rises greatly during the first 10 days of lactation at both temperatures.
• 8 At 21°C, body weight, excluding the weight of the litter, increases only slightly during pregnancy; but the weights of the heart and liver are greatly increased. The weight of the stomach also rises; the small intestine lengthens, but becomes lighter. During lactation the liver becomes still heavier, and the small intestine more than restores its loss of weight. The kidneys also become heavier. At – 3°C similar changes occur, but the heart is heavier at all stages of the reproductive cycle than it is at 21°C. The kidneys, too, are consistently heavier in the cold, and so is the small intestine. By contrast, the liver of pregnant or lactating females at – 3°C is no heavier than in the warm environment.
• 9 Pregnancy entails an increase in the absolute amount of nitrogen in the body, in both environments; but females at – 3°C have less nitrogen and collagen than controls. Pregnancy does not alter body fat at either temperature, but lactation is accompanied by some loss. At birth, mice born in the cold environment have more than twice as much body fat as controls.
• 10 When mice are bred for their full reproductive span, the effect of a cold environment depends markedly on genotype. Mice of strain A2G/Tb eventually produce as many young in the cold environment as in the warm, but take longer to do so; C57BL/Tb produce fewer young, Wild mice produce fewer litters at – 3°C, and have a much higher nestling mortality. Most of the mortality is due to loss of whole litters.
• 11 The preceding statements apply to mice of the first two or three generations in a cold environment, There are further effects of breeding for many generations in the cold. Wild mice bred for ten generations lose fewer litters in later than in earlier generations. After ten generations, some wild mice were moved from –3 to 21°C. Their reproductive performance was then much superior to that of controls which had been kept at 21°C throughout. The transferred mice were also quicker than the controls to make a nest of paper.
• 12 Genetically heterogeneous laboratory mice, after twelve generations in the cold, were similarly returned to the warm environment. Their offspring were heavier than controls; but there was no superiority in reproductive performance.
• 13 A2G/Tb mice kept at –3°C, though highly inbred, also improved in reproductive performance over a number of generations: in particular, their infant mortality declined. This was probably not due to a genetical change, but to a cumulative maternal effect.
• 14 Maternal performance was studied by cross-fostering young at birth between these ‘Eskimo’ mice, ‘immigrant’ mice of the first or second generation reared in the cold, and controls at 21°C. There was some evidence of an effect of true parentage, regardless of foster parentage, on body weight: the young of the Eskimo mice tended to be heavier than the others. There was also evidence that this influence persisted into a second generation. Mortality among the fostered young was influenced only by true parentage, not by foster parentage or environmental temperature. Some of the fostered mice were mated. Again, among their young, mortality in the nest was not affected by environmental temperature; but those whose true ancestry was Eskimo displayed a lower mortality than the others.
• 15 If a young mammal is given special treatment (such as exposure outside the nest), the treatment may influence, not only the individual treated, but also the behaviour of the parents; and the altered parental behaviour may in turn affect the development of the young. Enhanced parental attention in the nest has been directly observed after young have been exposed to cold or other treatment. It can probably accelerate maturation, and improve reproductive performance by lowering mortality among the young of the treated mice. Hence the direct effects of treatment in infancy can never be distinguished with certainty from indirect effects through changed parental behaviour, unless the experimental animals are reared artificially.
• 16 A comprehensive theory of ‘stress’, that is, of the response of a species to an environmental change for the worse, requires that attention should be paid to the following: (i) the effects of physiological (ontogenetic) adaptation to one ‘stressor’, such as cold, on response to another, such as infection; (ii) the ways in which conditions of rearing, especially early exposure to mildly adverse conditions such as lower temperature, influence later physiological, reproductive and behaviour al performance; (iii) the relationships of the above with the adaptive changes of pregnancy and lactation.

     

Frequency-dependent contractile response of isolated cardiac trabeculae under hypo-, normo-, and hyperthermic conditions.

The body is from time to time exposed to nonnormothermic conditions; both hypo- and hyperthermia can occur as a result of external (environment) or internal (pathogens, allergens) stressors. To preserve life under hypo- and hyperthermic conditions, adequate perfusion of vital organs is mandated. Although cardiac output regulation under hyperthermic conditions has been studied, the mechanical response of basic contractile function of the myocardium itself is incompletely understood. Accordingly, we set out to test mechanical output of isolated myocardium under hyperthermic conditions and to compare the results with the hypo- and normothermic response in the same tissue. We observed that, in absence of a frequency change, developed force decreased markedly. At a physiological normal stimulation rate of 6 Hz, developed force decreases to 67.2 +/- 2.6% at 42 degrees C compared with 37 degrees C. In addition, twitch timing characteristics also accelerate, allowing for a faster relaxation; time from peak tension to 50% relaxation is approximately 23% faster (from 31.4 +/- 2.6 to 24.4 +/- 1.7 ms). Although this faster relaxation in turn prevents a steep increase in diastolic tension at high frequencies, the very fast calcium kinetics now prevent a more complete activation of the myofilaments, resulting in a lower twitch-force maximum at hyperthermic conditions. Even at maximal beta-adrenergic stimulation, developed force is well below levels reached at physiological temperature.     

Effects of microwave exposure and temperature on survival of mice infected with Streptococcus pneumoniae

Female CD-1 mice were injected with an LD₅₀ dose of Streptococcus pneumoniae and then exposed to 2.45 GHz (CW) microwave radiation at an incident power density of 10 mW/cm² (SAR = 6.8 W/kg), 4 h/d for 5 d at ambient temperatures of 19 °C, 22 °C, 25 °C, 28 °C, 31 °C, 34 °C, 37 °C and 40 °C. Four groups of 25 animals were exposed at each temperature with an equal number of animals concurrently sham-exposed. Survival was observed for a 10-d period after infection. Survival of the sham-exposed animals increased as ambient temperature increased from 19 °C–34 °C. At ambient temperatures at or above 37 °C the heat induced in the body exceeded the thermoregulatory capacity of the animals and deaths from hyperthermia occurred. Survival of the microwave-exposed animals was significantly greater than the shams (～20%) at each ambient temperature below 34 °C. Based on an analysis of the data it appears that the hyperthermia induced by microwave exposure may be more effective in increasing survival in infected mice than hyperthermia produced by conventional methods (ie, high ambient temperature). Microwave radiation may be beneficial to infected animals at low and moderate ambient temperatures, but it is detrimental when combined with high ambient temperatures.     

Neuroimmunology: modulation of the hamster immune system by photoperiod

Groups of adult male Syrian hamsters were kept in a long photoperiod (LD 14:10) or a short photoperiod (LD 10:14). After 12 weeks, half of the animals in each light:dark cycle were immunized with an immunogenic amino acid polymer. Exposure to short photoperiod was associated with a significant reduction in testicular, accessory sex organ, splenic and brown fat weights. However, photoperiod length did not influence whole body, thymic, adrenal or kidney weights. Spleens of immunized animals in the long photoperiod were significantly heavier than those of unimmunized animals in the long photoperiod, and both were heavier than spleens from immunized or unimmuized animals in the short photoperiod. This reflected increased splenic lymphocyte and macrophage counts. However, there was no difference in antibody production between animals kept in different photoperiods. These results demonstrate that the daily photoperiod length affects both hamster reproductive competence as well as selected immune parameters (splenic weight and mononuclear cell hyperplasia) but does not alter antibody production.     

Geographic mosaics of phenology,host preference,adult size and microhabitat choice predict butterfly resilience to climate warming

The climate‐sensitive butterfly Euphydryas editha exhibited interpopulation variation in both phenology and egg placement, exposing individuals to diverse thermal environments. We measured ‘eggspace’ temperatures adjacent to natural egg clutches in populations distributed across a range of latitudes (36°8′–44°6′) and altitudes (213–3171 m). Eggs laid > 50 cm above the ground averaged 3.1°C cooler than ambient air at 1 m height, while eggs at < 1 cm height averaged 15.5°C hotter than ambient, ranging up to 47°C. Because of differences in egg height, eggs at 3171 m elevation and 20.6°C ambient air experienced mean eggspace temperatures 7°C hotter than those at 213 m elevation and ambient 33.3°C. Experimental eggs survived for one hour at 45°C but were killed by 48°C. Eggs laid low, by positively geotactic butterflies, risked thermal stress. However, at populations where eggs were laid lowest, higher oviposition would have incurred incidental predation from grazers. Interpopulation variation in phenology influenced thermal environment and buffered exposure to thermal stress. At sites with hotter July temperatures, the single annual flight/oviposition period was advanced such that eggs were laid on earlier dates, with cooler ambient temperatures. The insects possessed two mechanisms for advancing egg phenology; they could advance timing of larval diapause‐breaking and/or shorten the life cycle by becoming smaller adults. Mean weight of newly‐eclosed females varied among populations from 92 to 285 mg, suggesting that variable adult size did influence phenology. Possible options for in situ mitigation of thermal stress include further advancing phenology and raising egg height. We argue that these options exist, as evidenced by current variation in these traits and by failure of E. editha to conform to restrictive biogeographic constraints, such as the expectation that populations at equatorial and poleward range limits be confined to higher and lower elevations, respectively. This optimistic example shows how complex local adaptation can generate resilience to climate warming.     

The effect of hyperthermia on radiation-induced carcinogenesis

Ten groups of mice were exposed to either a single (30 Gy) or multiple (six fractions of 6 Gy) X-ray doses to the leg. Eight of these groups had the irradiated leg made hyperthermic for 45 min immediately following the X irradiation to temperatures of 37 to 43 degrees C. Eight control groups had their legs made hyperthermic with a single exposure or six exposures to heat as the only treatment. In mice exposed to radiation only, the postexposure subcutaneous temperature was 36.0 +/- 1.1 degrees C. Hyperthermia alone was not carcinogenic. At none of the hyperthermic temperatures was the incidence of tumors in the treated leg different from that induced by X rays alone. The incidence of tumors developing in anatomic sites other than the treated leg was decreased in mice where the leg was exposed to hyperthermia compared to mice where the leg was irradiated. A systemic effect of local hyperthermia is suggested to account for this observation. In mice given single X-ray doses and hyperthermia, temperatures of 37, 39, or 41 degrees C did not influence radiation damage as measured by the acute skin reactions. A hyperthermic temperature of 43 degrees C potentiated the acute radiation reaction (thermal enhancement factor 1.1). In the group subjected to hyperthermic temperatures of 37 or 39 degrees C and X rays given in six fractions, the skin reaction was no different from that of the group receiving X rays alone. Hyperthermic temperatures of 41 and 43 degrees C resulted in a thermal enhancement of 1.16 and 1.36 for the acute skin reactions. From Day 50 to Day 600 after treatment, the skin reactions showed regular fluctuations with a 150-day periodicity. Following a fractionated schedule of combined hyperthermia and X rays, late damage to the leg was less than that following X irradiation alone. Mice subjected to X rays and hyperthermic temperatures of 41 and 43 degrees C had a lower median survival time than the mice treated with hyperthermia alone. This effect was not associated with tumor incidence.     

High temperature acclimation alters the emersion behavior in the crab Neohelice granulata

An increase in environmental temperature can deleteriously affect organisms. This study investigated whether the semiterrestrial estuarine crab Neohelice granulata uses emersion behavior as a resource to avoid thermal stress and survive higher aquatic temperatures. We also examined whether this behavior is modulated by exposure to high temperature; whether, during the period of emersion, the animal loses heat from the carapace to the medium; and whether this behavior is altered by the temperature at which the animal has been acclimated. The lethal temperature for 50% of the population (LT₅₀) was determined through 96-h mortality curves in animals acclimated at 20 °C and 30 °C. The behavioral profile of N. granulata during thermal stress was based on monitoring crab movement in aerial, intermediary, and aquatic zones. Acclimation at a higher temperature and the possibility of emersion increased the thermotolerance of the crabs and the synergistic effect of acclimation temperature. The possibility of leaving the hot water further increased the resistance of these animals to thermal stress. We observed that when the crab was subjected to thermal stress conditions, it spent more time in the aerial environment, unlike under control conditions. Under the experimental conditions, it made small incursions into the aquatic environment and stayed in the aerial environment for a longer time in order to cool its body temperature. The animals acclimated at 20 °C and placed into water at 35 °C remained in the aerial zone. The animals acclimated and maintained at 30 °C (control) that were placed in water at 35 °C with the possibility of emerging into hot air transited more frequently between the aquatic and aerial zones than did the animals that were put in water at 35 °C with the possibility of emerging into a cooler air environment. We conclude that emergence behavior allows N. granulata to survive high temperatures and that this behavior is influenced by acclimation temperature.     

Weight of food and time required to satiate brown trout, Salmo trutta L.

Brown trout of different weights (range 8-358 g) were fed to satiation at fifteen different water temperatures (range 3.8–21.6°C. Both the weight of the trout (Wg) and the water temperature (T°C) affected the maximum weight of food (Q mg) consumed in a meal, and the relationship between the three variables was well described by a multiple regression equation which can be used to estimate the value of Q (with 95% confidence limits) for trout of different weights at different temperatures between 3.8°C and 21.6°C. The satiation time (with 95% confidence limits) can also be estimated from a multiple regression equation for trout of different weights at temperatures between 6.8°C and 18.1°C. Estimates from the multiple regression equations were applicable to a wide range of food organisms with the exception of larvae ofTenebrio molitor (mealworms). Appetite (measured by voluntary food intake) varied with temperature and was greatest between 13.3°C and 18.4°C. From comparisons with the results of other workers, it was concluded that the maximum amount of food consumed in a meal may provide sufficient calories for both the daily metabolic requirements and the daily maintenance requirements of a trout at temperatures between 3.8°C and 18.4°C, but not at temperatures above 18.4°C.     

Evidence that the hypothermic response of mice to delta-9-tetrahydrocannabinol is not mediated by changes in thermogenesis in brown adipose tissue.

Delta 9-Tetrahydrocannabinol (20 mg/kg i.p.) and propranolol (20 and 50 mg/kg i.p.) produced marked falls in the rectal temperatures of mice kept at an ambient temperature of 22 degrees C. Propranolol (50 mg/kg i.p.) also decreased the thermogenic activity of brown fat, as measured by a decrease in the level of [3H]GDP binding to mitochondria obtained from mouse interscapular brown adipose tissue. In contrast, delta 9-tetrahydrocannabinol (20 mg/kg i.p.) did not affect mitochondrial GDP binding even though the dose used was one shown previously to depress heat production. GDP binding was also unaffected by this cannabinoid in brown adipose tissue taken from mice that had been kept at 13 degrees C instead of 22 degrees C. In mice kept at 34 degrees C, isoprenaline (0.25 and 1.0 mg/kg s.c.) induced a marked rise in rectal temperature and increased the level of GDP binding to brown fat mitochondria. Propranolol (50 mg/kg i.p.) prevented the hyperthermic response to isoprenaline, the mice becoming hypothermic instead. Delta 9-Tetrahydrocannabinol (20 mg/kg i.p.) had no effect on isoprenaline-induced hyperthermia. We conclude from these data that there is no significant involvement of brown adipose tissue in the hypothermic response of mice to delta 9-tetrahydrocannabinol.     

The effect of temperature on embryo survival and development in pallid sturgeon Scaphirhynchus albus (Forbes & Richardson 1905) and shovelnose sturgeon S. platorynchus (Rafinesque, 1820)

The thermal response of pallid sturgeon Scaphirhynchus albus and shovelnose sturgeon S. platorynchus embryos was determined at incubation temperatures from 8 to 26°C and 8 to 28°C, respectively. The upper and lower temperatures with 100% (LT₁₀₀) embryo mortality were 8 and 26°C for pallid sturgeon and 8 and 28°C for shovelnose sturgeon. It was concluded that 12–24°C is the approximate thermal niche for embryos of both species. Generalized additive and additive‐mixed models were used to analyze survival, developmental rate and dry weight data, and predict an optimal temperature for embryo incubation. Pallid sturgeon and shovelnose sturgeon embryo survival rates were different in intermediate and extreme temperatures. The estimated optimal temperature for embryo survival was 17–18°C for both species. A significant interaction between rate of development and temperature was found in each species. No evidence was found for a difference in timing of blastopore, neural tube closure, or formation of an S‐shaped heart between species at similar temperatures. The estimated effects of temperature on developmental rate ranged from linear to exponential shapes. The relationship for rate of development to temperature was relatively linear from 12°C to 20°C and increasingly curvilinear at temperatures exceeding 20°C, suggesting an optimal temperature near 20°C. Though significant differences in mean dry weights between species were observed, both predicted maximum weights occurred at approximately 18°C, suggesting a temperature optimum near 18°C for metabolic processes. Using thermal optimums and tolerances of embryos as a proxy to estimate spawning distributions of adults in a river with a naturally vernalized thermal regime, it is predicted that pallid sturgeon and shovelnose sturgeon spawn in the wild from 12°C to 24°C, with mass spawning likely occurring from 16°C to 20°C and with fewer individuals spawning from 12 to 15°C and 21 to 24°C. Hypolimnetic releases from Missouri River dams were examined; it was concluded that the cooler water has the potential to inhibit and delay sturgeon spawning and impede embryo incubation in areas downstream of the dams. Further investigations into this area, including potential mitigative solutions, are warranted.     

Heritable variation in reaction norms of metabolism and activity across temperatures in a wild-derived population of white-footed mice (Peromyscus leucopus)

Heritable variation in metabolic traits is likely to affect fitness. In this study, white-footed mice from wild-derived photoresponsive [R, infertile in short day length (SD)] and non-photoresponsive (NR, fertile in SD) selection lines were maintained under short-day (SD 8Light:16Dark), sub-thermoneutral conditions (22 or 12 °C). Mice had significantly higher levels of food intake and resting metabolic rates (RMR) at low temperature. RMR differed significantly between lines (greater in NR mice). In contrast to previous work under thermoneutral conditions, there was no significant difference in overall activity or average daily metabolic rates (ADMR) of mice from the two lines. Reduced activity may reflect behavioral changes under cooler conditions (e.g., nest building) reducing the overall energetic cost of fertility (for NR mice). There was no significant difference in maximal rate of oxygen consumption ( $\dot V \text{O}_{\text {2max}} $ ) between lines. R mice had significantly greater brown adipose tissue and white abdominal fat mass due to both line and temperature. Reaction norms for intake, resting metabolism (RMR/BMR) and level of activity from current (12 and 22 °C) and previously published data (28 °C) demonstrate independent effects of genetics (line) and environment (temperature) for resting metabolism, but a clear interaction between these for activity. The results suggest that fertility under winter conditions imposes metabolic costs that are related to the level of reproductive development. Under the coldest conditions tested, however, mice that remained fertile in SD reduced activity, ADMR and food requirements, decreasing the differential between selection lines. Heritable variation in reaction norms suggests a genetic by environment effect that could be subject to selection.     

Actions and interactions of growth hormone and insulin-like growth factor-II: body and organ growth of transgenic mice

To characterize long-term actions and interactions of growth hormone (GH) and insulin-like growth factor-II (IGF-II) on postnatal body and organ growth, hemizygous phosphoenolpyruvate carboxykinase (PEPCK)-human IGF-II transgenic mice were crossed with hemizygous PEPCK-bovine GH transgenic mice. The latter are characterized by two-fold increased serum levels of IGF-I and exhibit markedly increased body, skeletal and organ growth. Four different genetic groups were obtained: mice harbouring the IGF-II transgene (I), the bGH transgene (B), or both transgenes (IB), and non- transgenic controls (C). These groups of mice have previously been studied for circulating IGF-I levels (Wolf et al., 1995a), whereas the present study deals with body and organ growth. Growth curves (week 3 to 12) were estimated by regression with linear and quadratic components of age on body weight and exhibited significantly (p < 0.001) greater linear coefficients in B and IB than in I and C mice. The linear coefficients of male I and C mice were significantly (p < 0.001) greater than those of their female counterparts, whereas this sex-related difference was absent in the bGH transgenic groups. The weights of internal organs as well as the weights of abdominal fat, skin and carcass were recorded from 3.5- to 8- month-old mice. In addition, organ weight-to-body weight-ratios (relative organ weights) were calculated. Except for the weight of abdominal fat, absolute organ weights were as a rule significantly greater in B and IB than in I and C mice. IGF-II overproduction as a tendency increased the weights of kidneys, adrenal glands, pancreas and uterus both in the absence and presence of the bGH transgene. Analysis of relative organ weights demonstrated significant (p < 0.05) effects of elevated IGF- II on the relative growth of kidneys (males and females) and adrenal glands (females), confirming our previous report on organ growth of PEPCK-IGF-II transgenic mice. In females, IGF-II and GH overproduction were additive in stimulating the growth of spleen and uterus, providing evidence for tissue-specific postnatal growth promoting effects by IGF-II in the presence of elevated IGF-I     

Der Einfluß der Umgebungstemperatur auf Motilität,Körpertemperatur und Sauerstoffverbrauch von normalen und Pervitin-behandelten Mäusen

Single mice were kept in various ambient temperatures (15° to 35° C) and motility, oxygen consumption, and body temperature were recorded. Untreated animals: Motility was least at 25° C room temperature. Relations between motility and body temperature were linear at all ambient temperatures. The body temperatures of very agile mice did not vary at ambient temperatures from 15° to 30° C whereas that of quiet mice was strongly influenced by the milieu. The relations between oxygen consumption and body weight were also linear at all ambient temperatures; the corresponding regression coefficients decreased progressively with rising ambient temperatures. Oxygen consumption increased at a constant rate with motility, independent of ambient temperatures. Animals treated with methamphetamine: The LD₅₀ of methamphetamine decreased considerably with rising ambient temperature. The influence on body temperature of methamphetamine was very variable and depended on both dose and ambient temperature. Toxic doses of methamphetamine induced hyperthermia in warm surroundings and hypothermia in a cool milieu. Under the influence of methamphetamine, oxygen consumption increased or decreased considerably with the body temperature. Ambient temperatures exerted an essential influence on the cause of death after toxic doses of methamphetamine.     

The effect of cave microclimate on winter roosting behaviour in the bat,Miniopterus schreibersii blepotis

The microclimate at Thermocline Cave (lat, 30° 45′S, long, 149° 43′E) was investigated by measuring air temperature and relative humidity at five stations on 18 occasions from September 1971 to December, 1973. The activity, body weight and roosting sites of the bat Miniopterus schreibersii blepotis in the cave were recorded on each visit. Relative humidity in the cave was generally high and paralleled temperature. The cave exhibited a range of temperatures from 9 to 19.5°C but bats selected roosting sites only in a part of this range. During the autumn when the bats arrived and were feeding, their body weights were low, and they roosted in a domed area at the rear of the cave with a temperature of 19.5°C. As they became less active and body weight increased they moved to cooler parts (9.5-11°C) towards the front of the cave and underwent periods of torpor, in one case lasting for at least 12 days. From July to September body weight decreased. The bats became more active in September and most had left the cave by October. It appears that M.s. blepotis can detect temperature differences of 1°C. They used this ability to select cold areas with stable high humidity in Thermocline Cave to under go periods of winter torpor.     

Effects of temperature and body size on radiocaesium retention in brown trout, Salmo trutta

1. The elimination rate of radiocaesium in brown trout Salmo trutta L. was determined in the laboratory at four water temperatures (range 4.4–15.6°C). In the experiments three or four homogenous size-groups of fish (mean weights 23–496 g) were studied at each temperature. 2. The brown trout received acute oral doses of ¹³⁴Cs and were killed at intervals for radioactivity counting. The retention versus time curves were composed of two distinct exponential components. The long-lived component was quantitatively the most important for retention of radiocaesium. Elimination rate increased with increasing water temperature and decreased with increasing body weight. 3. The biological half-life of ¹³⁴Cs (T_b, days) was related to fresh body weight (W, g) and water temperature (t, °C) by the equation: T_b= 290 ×W°.¹⁷⁶× e-°.^106×t. The elimination rate of Cs could be predicted from weight-specific metabolic rate as given by Elliott's equations for brown trout.     

Relative growth of tissues at different somatic growth rates in rainbow trout Salmo gairdneri Richardson

Growth of tissues (heart, spleen, liver, gonad, gut, skin, visceral fat and carcase) in immature rainbow trout relative to growth of whole fish, was examined by means of allometric analysis (y=ax^b; Huxley, 1932) of wet and dry weights. Relative growth rates of tissues are compared in an initial sample of fingerlings (< 11·29 g), and in fish (> 11·29 g) growing rapidly (at 12°C ad libitum rations) and slowly (at 12°C, 4–5% rations, and 7°C ad libitum rations). In the fingerlings of the initial sample, the major tissues by weight (liver, gut, skin, visceral fat) increased relatively more rapidly than whole body weight (i.e. with positive allometry; b> 1·00), and carcase increased more slowly than body weight (b< 1·00). Above fingerling size, the reverse holds: tissues other than carcase (with exception of visceral fat) increased less rapidly than body weight (b < 1·00), and carcase more rapidly (b > 1·00). These principles hold for post-fingerling, immature rainbow trout, regardless of growth rate differences of whole fish, and even in fish that also received bGH (bovine growth hormone). The characteristic b (slope) values in the allometry equations for the wet and dry weights of the various tissues tend to remain constant, despite whole fish growth rate differences and the effects of this constancy are to maintain approximate constancy of body proportional (%) wet and dry weights. It is emphasized however that the effect of b values only slightly > or < 1·00 can cause important changes in the proportional (%) weights of major tissues as fish continue to increase in size. In low (4–5%) rations fish (without bGH) the slope (b) value for gut is less than for fish on ad libitum rations with the result that gut proportional weight is significantly less among these fish. In fish on ad libitum rations at 7°C, the slope (b) value for skin is greater than for all other (12°C) groups; skin proportional weight for the 7°C group is therefore, significantly greater. The overall impression of relative growth in immature rainbow trout is of remarkable conservativeness of body proportional weights regardless of overall somatic growth rate.