The effect of myo-inositol on the ability of Ditylenchus dipsaci,D. myceliophagus and Anguina tritici to survive desiccation

• 1.1. The effect of myo-inositol on the ability of three species of nematodes to survive desiccation has been studied.
• 2.2. Survival rates obtained from worms treated with an inositol bathing medium were compared with survival rates of worms treated with distilled or tapwater media.
• 3.3. Highest survival rates were found in those nematodes that were placed in an inositol solution prior to desiccation.
• 4.4. Tapwater facilitated higher revival rates than did distilled water in both D. dipsaci and D. myceliophagous.
• 5.5. No such differences were found for A. tritici.
• 6.6. The results are discussed in relation to the possible mechanisms of protection afforded by the different bathing media.

     

Variation of l-gulonolactone oxidase activity in placental mammals

• 1.1. The activity of l-gulonolactone oxidase (EC 1.1.3.8) in livers of 49 species of eutherian mammals varied intraspecifically among individuals; coefficients of variation were 0.2 to 0.4 in many species.
• 2.2. Differences observed in l-gulonolactone oxidase activity among strains of laboratory rats and domestic rabbits are probably genetically controlled.
• 3.3. Pronounced sex differences in l-gulonolactone oxidase activity were found in some species, particularly in the genera Peromyscus, Reithrodontomys and Onychomys.
• 4.4. Mormota monax exhibited seasonal variation in l-gulonolactone oxidase somewhat like that previously observed in Sylvilagus floridanus; no such seasonal variation was found in Sciurus carolinensis.
• 5.5. Hibernation did not affect l-gulonolactone oxidase activity in Spermophilus tridecemlineatus.
• 6.6. In four species of rodents, Microtus ochrogaster, Tylomys panamensis, Octodon degus and Sigmodon hispidus, l-gulonolactone oxidase activity was not affected by the level of dietary ascorbate.

     

Water relations and thermal sensitivity of several cockroach species (Dictyoptera: Blattidae and blaberidae)

• 1.1. Per cent total body water content (%TBW), cuticular permeability (CP), rate of water loss, critical thermal maxima (CTMax), and upper lethal limits (ULL) were determined for Pacific beetle, Diploptera punctata (Eschscholtz), Surinam, Pycnoscelus surinamensis (L.), and Turkestan, Blaita lateralis (Walker), cockroaches.
• 2.2. Initial body mass ranged from 153.16 to 464.96 mg, for D. punctata and P. surinamensis cockroaches, respectively. Mean %TBW was 57.8 for P. surinamensis and 67.7 for B. lateralis.
• 3.3. Mean cuticular permeability was not related to initial mass and ranged from 20.9 to 38.7 μg/cm²/hr/mmHg for D. punctata and P. surinamensis, respectively.
• 4.4. Cumulative mass loss and %TBW lost increased linearly with desiccation time.
• 5.5. CTMax ranged from 43.2°C for D. punctata to 44.3°C for P. surinamensis. There were significant, but small differences in CTMax among the three species.
• 6.6. ULL were 2.2 to approximately 4°C greater than CTMax. The greatest ULL was 48.1°C for B. lateralis and the lowest ULL was 45.0°C for D. punctata.

     

Osmoregulation and temperature effects on water loss and oxygen consumption in two species of african scorpion

• 1.1. Aspects of the physiology of two southern African scorpions have been examined. The scorpions are the large desert species Parabuthus villosus (Peters) (Buthidae) and the more mesic, burrowing species Opisthophthalmus capensis (Herbst) (Scorpionidae).
• 2.2. Evaporative water losses were higher in Opisthophthalmus at all temperatures.
• 3.3. Analysis of haemolymph during prolonged desiccation showed good osmotic and ionic regulation in Parabuthus but no regulation in Opisthophthalmus.
• 4.4. Oxygen consumption of Parabuthus was measured after acclimation to 10 and 30°C. Metabolic rates were extremely low but there was no metabolic compensation to increased temperatures.

     

Environmental and genetic influences on the thermal physiology of Rana sylvatica

• 1.1.|Intraspecific variation in the thermal physiology of Rana sylvatica was examined.
• 2.2.|Heat and cold tolerances of both adult and larval representatives were determined for animals representing populations from New York, Maryland, Kentucky, Ohio, Michigan and Canada.
• 3.3.|In general, frogs from more northern localities exhibited lower heat tolerances.
• 4.4.|There was no evidence of interpopulational differences in cold tolerance. Similar trends were revealed by larval testing.
• 5.5.|Interpopulational differences among laboratory-reared tadpoles suggests a strong genetic component to Rana sylvatica thermal physiology.

     

The regulation of glucose 6-phosphate dehydrogenase from Dicentrarchus labrax (bass) liver

• 1.1. Kinetic constant values of the reaction catalyzed by bass liver glucose 6-phosphate dehydrogenase show to be modified between 10 and 40°C.
• 2.2. The Arrhenius plot between 10 and 50°C shows two slopes with different activation energies.
• 3.3. These results suggest a regulation of this enzyme by environmental temperature.
• 4.4. Kinetics of ATP inhibition were examined between pH 6.2 and 7.8: patterns and K_i values obtained are affected by the pH variation.
• 5.5. NADH is an effective inhibitor of bass glucose 6-phosphate dehydrogenase but this enzyme does not show NAD-linked activity.
• 6.6. Kinetics of pyridoxal 5′-phosphate inhibition have indicated the presence of a lysine in the catalytic site for NADP⁺.

     

Blood values in South American lizards from high and low altitudes

• 1.1. Blood indices were measured in 27 species of lizard from Chile and Argentina occurring at different altitudes ranging from sea-level up to 4600 m.
• 2.2. Contrary to amphibians, none of the hematological values of these lizards, such as hematocrit, hemoglobin concentration, red cell count, mean cell volume, mean cell hemoglobin and mean cell hemoglobin concentration, were found to be correlated with their altitudinal distribution.
• 3.3. Intrageneric comparison of blood values in Liolaemus lizards (seven highland species living above 3000m and 12 lowland species) showed a similar degree of independence from their altitudinal site of capture or from their upper limit of distribution.
• 4.4. As reported for other vertebrate taxa, an inverse correlation between size and number of red blood cells was also found in the studied reptiles.

     

Thermal properties for digestive enzymes of a sub-antarctic beetle,hydromedion sparsutum (coleoptera,perimylopidae) compared to those in two thermophilic insects

• 1.1. Proteolytic, lipolytic, amylolytic and cellulolytic activities were studied in adults of the phytophagous beetle, Hydromedion sparsutum, indigenous to the sub-Antarctic island of South Georgia.
• 2.2. Gastric enzyme activities were measured at experimental temperatures of 5–40°C and results were compared with those obtained from two thermophilic insects, Gryllus bimaculatus and Tenebrio molitor.
• 3.3. Protease and lipase activities in Hydromedion were 10–15 times lower than in Gryllus and Tenebrio.
• 4.4. In the temperature range of 5–15°C, α-amylase activity from Hydromedion was only slightly lower than that from Gryllus.
• 5.5. Hydromedion gut homogenates exhibited a distinct cellulolytic activity, even at a low temperature of 5°C.
• 6.6. Cellulolytic activity in the digestive tract of Hydromedion was confirmed by the evolution of ¹⁴CO₂ after consumption of labelled cellulose.
• 7.7. The thermal properties of digestive enzymes agree well with the role of Hydromedion as primary decomposer in its ecosystem.

     

Metabolic responses of Cassin's Finches (Carpodacus cassinii) to temperature

• 1.1. The thermal neutral zone of Cassin's Finches extends from 22 to 37.5°C.
• 2.2. Standard metabolism (40.1 Wm⁻² or 7.6kcal bird⁻¹ day⁻¹) of the 28 g birds was 89% of the value predicted for passerines measured at night.
• 3.3. At temperatures below the zone of thermal neutrality metabolism is described by the relation, Wm⁻² = 1.55–74.5°C. The coefficient of heat transfer (1.55Wm⁻²°C⁻¹) is only 58% of the value predicted for birds of this size, indicating excellent insulation.
• 4.4. At temperatures above thermal neutralzfsity metabolism is described by the relation, Wm⁻² = 2.75–62.6°C.
• 5.5. Under conditions of heat stress (44.5°C; P_H2O = 8.6 Torr) Cassin's Finches were able to dissipate up to 208% of their metabolic heat production by evaporative water loss. Maximal rate of water loss was 56 mg g⁻¹ hr⁻¹.
• 6.6. At 20°C resting fasted finches lost a mean of 4.94 ± 1.5 SD mg H₂O g⁻¹hr⁻¹.

     

Circadian rhythms of determined blood chemistry values in buzzards and eagle owls

• 1.1. Fifteen values were determined in blood samples from six buzzards (Buteo buteo) and six eagle owls (Bubo bubo) over the 24 hr of the day.
• 2.2. Glucose, urea, uric acid, triglyceride and calcium values showed diurnal rhythms in both species. Their respective patterns of diurnal variation were compared.
• 3.3. Phosphorus, cholesterol and cholinesterase levels underwent circadian rhythms only in the buzzards. Albumin/globulin and amylase exhibited diurnal variations exclusively in the eagle owls.
• 4.4. Glutamatic oxaloacetic transaminase, albumin, globulin, total protein and creatinine concentrations did not show diurnal rhythms in either of the species.
• 5.5. Blood values of the different parameters were studied on the basis of the ranges described in birds.

     

Heart rates of adult red-spotted newts,Notophthalmus viridescens in air and submerged in normoxic and hypoxic water at different temperatures

• 1.1. Heart rates of adult aquatic red-spotted newts can be conveniently recorded using an impedance pneumograph.
• 2.2. Heart rates decrease linearly with decreasing temperature.
• 3.3. Submergence in normoxic and hypoxic water at 10°, 15°, and 20°C results in bradycardia which is more pronounced in hypoxic water.
• 4.4. At 5°C one newt exhibited the above pattern, but bradycardia was not exhibited by the other newt during normoxic submergence.
• 5.5. Diminishing heart rates are probably due to oxygen deficiency, not immersion alone.
• 6.6. Recovery from bradycardia in air is rapid and not linked with resumption of aerial breathing.

     

Characterization of NaK ATPase from the gills of the freshwater prawn Macrobrachium rosenbergii (de Man)

• 1.1. The specific activity of Na-K ATPase was determined from the microsomal preparation of gills dissected from adult Macrobrachium rosenbergii.
• 2.2. Maximal ATPase activity was achieved at a substrate concentration of 0.5 mM ATP.
• 3.3. Optimal enzyme activity was obtained at pH of 7.5.
• 4.4. The Arrhenius plot of Na-K ATPase activity revealed a marked discontinuity at 30°C. “Mg” ATPase activity did not exhibit a marked discontinuity.
• 5.5. The E_a for Na-K ATPase and “Mg” ATPase was 14.6 kCal/mole and 9.31 kCal/mole respectively. Q₁₀ values for Na-K ATPase was 2.34 and for “Mg” ATPase 1.65.
• 6.6. ATPase activity and gill homogenate protein concentration exhibited a linear relationship up to 130 μg protein/ml.
• 7.7. Na-K ATPase activity was inhibited by 10⁻³ M ouabain. It was equally inhibited by the removal of K⁺ from the reaction medium.

     

Populational analysis of thermal responses—I. Changes in the heat resistance of muscle tissue and contractile muscle models of Salamandra salamandra larvae

• 1.1.|Study has been made of the heat resistance of m. rectus superficialis and their contractile models of larvae of 12 families of Salamandra salamandra kept at three different temperatures: 14, 21 (optimal) and 27°C. The heat resistance of the organism has been studied only in larvae kept at 21°C.
• 2.2.|An inverse linear relation has been found between the level of the average heat resistance of muscles for offspring, of the same family, under optimal conditions and its increase caused by a change in environmental temperature. A similar relationship was observed in contractile muscle models. This implies that a population responds to a change in environmental temperature as a function al system.
• 3.3.|The analysis of individual differences in the pattern of response of muscles, and their contractile models, to changes in environmental temperature allows the systemal and individual components to be isolated. The extent of co-ordination in responses of different individuals of the population can be evaluated from the proportion of the systemal component. The value of this component varies from 0.60 to 0.90.
• 4.4.|Selective advantage during thermal selection belongs to individuals with lower heat resistance of muscles.

     

Hydrolysis of glycol chitin by chitinolytic enzymes

• 1.1. The hydrolysis of glycol chitin preparations by several β-N-acetylglucosaminidases was monitored colorimetrically with the potassium ferriferrocyanide reagent.
• 2.2. Glycol chitin samples from crab and insect sources varied considerably in chemical composition and susceptibility to enzymatic hydrolysis.
• 3.3. Insect endochitinase preferred crab glycol chitin as substrate while hen's egg white lysozyme preferred commercial glycol chitin.
• 4.4. Insect glycol chitin was well hydrolyzed by both enzymes.
• 5.5. Insect exochitinase did not digest glycol chitin.

     

Effects of temperature and acid stress on hatching,survival capacity,metabolism and postural reflexes in caenid mayflies (ephemeroptera)

• 1.1. Mortality was 100% at pH 3.5 over a temperature range of 10–30°C for embryos and nymphs of Caenis diminuta and C. hilaris.
• 2.2. Hatching success for both species was highest at pH values above 4.5.
• 3.3. Survival capacities were significantly higher at 20°C over a pH range of 4.0-7.2.
• 4.4. Oxygen consumption rates increase as a function of increasing temperature and reduced acidity.
• 5.5. Loss of the nymphal righting response was observed at pH 3.5. This response can be used as a behavioral assay for acid stress.

     

The influence of aerial exposure on gas exchange and cardiac activity in the shore crab,Carcinus maenas (L.)

• 1.1. The cardiovascular physiology of adult Carcinus maenas (L.) emerging into air has been investigated at three different air temperatures.
• 2.2. Transition from seawater to air or vice versa triggered transient increases in cardiac and locomotor activity.
• 3.3. However, crabs became inactive 5–10 min after emerging from seawater (15°C) into air at the same temperature (15°C) or at lower temperatures (12–13°C) and heart rate fell.
• 4.4. At higher air temperatures (18–20°C) heart rate rose but to a lesser extent than predicted from aquatic Q₁₀ heart-rate values.
• 5.5. Crabs were again quiescent in aerial conditions.
• 6.6. Mean arterial oxygen tension (Pa_o2) was ~ 74 mmHg in submerged crabs but fell to ~ 38 mmHg in air while mean arterial carbon dioxide tension (Pa_o2) increased from 1 to 4 mmHg resulting in respiratory acidosis.
• 7.7. A model of gill function is proposed to explain the development of internal hypoxia in air.
• 8.8. The results are discussed in relation to the distribution of adult and juvenile C. maenas in situ.

     

The effect of temperature on the acid-base status of the blood of the hatching quail (Coturnix c. japonica)

• 1.1. The ambient temperature of embryos of pipped eggs was reduced from 38 to 28°C for a period of 45 min.
• 2.2. The blood P_CO2 was lower and the blood more alkaline at 28°C than at 38°C.
• 3.3. At 28°C plasma [HCO₃⁻] ] was lower than predicted from the blood buffer line determined in vitro.
• 4.4. The plasma concentrations of strong ions and lactate were the same at both temperatures.
• 5.5. After the ambient temperature had been returned to 38°C for a period of 45 min, blood pH was more acidic than before cooling, but there was no difference in blood P_CO2.
• 6.6. The plasma [HCO₃⁻] was the same as that at 28°C and plasma [K⁺] was higher than before cooling.
• 7.7. The results arc discussed in relation to the factors affecting blood pH in embryos at this stage of development.

     

Soluble eye lens proteins of Italian ictalurids

• 1.1. Soluble eye lens proteins of three species of Italian freshwater ictalurids were analyzed: Ictalurus sp., I. nebulosus marmoratus and I. punctatus.
• 2.2. The electrophoretic and isoelectric focusing patterns were compared.
• 3.3. Both techniques revealed species-specific patterns. I. sp. and I. nebulosus marmoratus exhibited very similar patterns, I. punctatus a quite distinct one.
• 4.4. Some hypotheses warranting further investigation of the subject were proposed.

     

Purification and characterization of elastase from the pyloric caeca of rainbow trout (Oncorhynchus mykiss)

• 1.1. An elastase-like enzyme was purified from the pyloric caeca of rainbow trout by hydrophobic interaction, cation exchange and gel-filtration chromatography.
• 2.2. The approximate molecular weight of the elastase was 27 kDa and the isoelectric point was remarkably basic.
• 3.3. The pH optimum of this enzyme was 8.0, when assayed with Succinyl-Ala-Ala-Ala-p-Nitroanilide.
• 4.4. When assayed with Succinyl-Ala-Ala-Ala-p-Nitroanilide, the enzyme activity had a temperature optimum of 45°C, and the enzyme was stable up to this temperature.
• 5.5. The trout elastase exhibited a higher specific activity than porcine elastase against Succinyl-Ala-Ala-Ala-p-Nitroanilide and elastin-orcein.
• 6.6. The trout elastase was inhibited by elastatinal, PMSF, TPCK, SBTI and Bowman-Birk inhibitor.

     

Hypothermia and blood of crabs

• 1.1. The effect of acclimation to 10° and 30°C on the blood volume, clotting time, total blood protein and numbers of cells was determined in Uca pugilator.
• 2.2. There was no significant difference between blood volume in the 10° and 30° animals but there were significantly more cells and a higher blood protein in the 30° crabs.
• 3.3. The clotting time is significantly longer for the 10° crabs.
• 4.4. These changes associated with the blood parameters can be associated with the ecology of the animal.