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1.
《Comparative biochemistry and physiology. A, Comparative physiology》1981,68(3):429-436
- 1.1. Some aspects of the gas exchange system of a diving lizard, Physignathus lesuewii were studied.
- 2.2. Breathing patterns were analysed.
- 3.3. Breathing rate increases logarithmically with temperature and Q10 = 1.8. LogBR = −0.237 + 0.0256 T.
- 4.4. Gas tensions in lung air and arterial and venous blood were measured. Arterial pH declines with increasing temperature.
- 5.5. Temperature has a marked effect on oxygen affinity of the blood (ΔH = −10.1 kcal mol−). A Bohr effect was also noted.
- 6.6. CO2 equilibrium curves were drawn.
- 7.7. The results are considered with a view to anticipating the efficiency of the gas exchange system of this species under conditions of variable temperature and during diving.
2.
《Comparative biochemistry and physiology. A, Comparative physiology》1984,77(4):539-545
- 1.1. Resting metabolic rates (RMR) below thermoneutrality in adult hyrax acclimated to 26, 15 and 10°C remained unchanged, i.e. thermal conductance (K) remained constant.
- 2.2. Conductance in juveniles decreased with acclimation to lower ambient temperatures (Ta).
- 3.3. Body temperature (Tb) dropped by 3.8°C in adults exposed to Ta of 30 – 5°C. The decrease was constant.
- 4.4. Body temperature fell by 1.5°C in juveniles exposed to Ta of 30 – 20°C but stabilized between 20 and 5°C.
- 5.5. The labile Tb, associated with behavioural strategies and lower than predicted RMR, can be seen as an energy-conserving mechanism of particular importance during winter conditions.
3.
《Comparative biochemistry and physiology. A, Comparative physiology》1982,71(3):469-472
- 1.1. Quick sinusoidal temperature fluctuations (constant average 10°C) cause an increase in metabolism in comparison to an invariable constant ambient temperature of the same dimension.
- 2.2. At the observed mean value of 10°C metabolism is increased by 0.8% per 1 K/hr based on the values of resting metabolic rate (correlation: M = 53.5 + 0.445 Ta, M in J/K g hr, Ta = ambient temperature change in K/hr) and 0.6% based on the values of activity metabolism (M = 70.4 + 0.425 Ta).
- 3.3. The absolute augmentation of metabolism per 1 K/hr is, by comparison, the same for day and night. Its amount is 0.42 and 0.43 J/K g hr respectively.
- 4.4. In the response of metabolism to temperature fluctuations no differences could be found with respect to the amplitude and frequency modifications of temperature.
- 5.5. The increase of energy consumption is probably caused to a greater extent by “overshoot” of the feedback control system in the course of adjusting metabolism to new levels according to the ambient temperature conditions.
- 6.6. Short term ambient temperature changes (i.e. measuring different temperature levels in one night to test basic metabolism vs ambient temperature) cannot produce reasonable values for basic metabolic rate, since these artificially high values reflect the testing procedure.
4.
《Comparative biochemistry and physiology. A, Comparative physiology》1979,62(4):827-830
- 1.1. Thermoregulatory and metabolic responses of dik-dik (Madoqua kirkii) were measured over an ambient temperature (Ta) range of 10–45°C.
- 2.2. The lower critical temperature was estimated at Ta 25°C.
- 3.3. At Ta 40 and 45°C, dik-dik panted and oxygen consumption fell below that measured at thermoneutrality.
- 4.4. The dik-dik appears well adapted to a high Ta but can cope with a low Ta only at a high metabolic cost.
5.
《Journal of thermal biology》2002,27(5):365-369
- 1.Measurements of body temperature (Tb) in the field demonstrate that Platypedia putnami var. lutea Davis regulates Tb through behavioral mechanisms.
- 2.Thermal responses (minimum flight temperature 17.3°C, maximum voluntary tolerance-temperature 32.5°C, and heat torpor temperature 44.4°C) of P. putnami var. lutea are related to the altitude of their habitat.
- 3.Water loss rates increase with ambient temperature (Ta). Water loss rates are not significantly different at the extremes of the active Tb range but increase significantly when exposed to elevated Ta.
- 4.Acoustic activity was restricted at 6.7°C Tb range. This is similar to the lower end of the Tb range for singing measured in cicada species that produce sound with a timbal mechanism.
- 5.The use of the wing musculature to produce acoustic signals in P. putnami var. lutea does not increase the Tb range over which the species can call compared to timbal calls produced by other cicada species.
6.
Body temperature response of young chicks to intraventricular injections of various cations and EGTA
- 1.1. The effect of intraventricular injections of various cations or ethylene glycol bis [β-amino ethyl ether]-N,N,N'N-tetra acetic acid (EGTA) on cloacal body temperature (Tc) of young chicks (Gallus domesticus) was investigated.
- 2.2. K+ and Mg2+ had no effect on Tc while Mn2+ caused a significant decrease.
- 3.3. Na+ and EGTA caused a significant increase in Tc.
- 4.4. The control of the set point for body temperature of chicks is similar to that observed in mammals.
7.
《Comparative biochemistry and physiology. A, Comparative physiology》1989,92(3):393-402
- 1.1. Diurnal cycles of body temperature, Tb, and energy metabolism, M, at different ambient temperatures (Ta: +5 −+ 32°C) were tested in 13 sunbird species from various habitats and of different body masses (5.2–14.2 g) including one of the smallest passerines, Aethopyga christinae.
- 2.2. Resting M-level (night) reaches Ta-dependent mean values of 54% (+5°C) and 49% (+25°C) of activity M-levels (day). Expected level is ca 75%.
- 3.3. Resting metabolic rate of sunbirds lies within the range of theoretically expected values for birds.
- 4.4. Mean linear metabolism-weight regression of the night values follows: M = 0.102 × W0.712 (M = energy metabolism in kJ/hr and W = body mass in g).
- 5.5. Thermal conductances, Tc, are lower (−24%) than the predicted values. This is caused by a decrease of Tb at low Ta. Mean nocturnal Tc is 3.2 J/g × hr × °C, mean day-time value is 4.3 J/g × hr × °C.
- 6.6. The zone of thermoneutrality is, in most species, within a Ta-range of 24–28°C.
- 7.7. Normal day and night levels of Tb are in the same range as reported for other birds of the same weight class. Tb decreases slightly with falling Ta (partial heterothermia). Lowest recorded Tb was 34.2°C.
- 8.8. No species tested showed any sign of torpor at night, independent of Ta, body mass or habitat origin.
8.
《Comparative biochemistry and physiology. A, Comparative physiology》1978,59(4):661-663
- 1.1. A study has been made of the thermostability (thermal shrinkage Ts values have been determined) of tissue collagen of 30 fish species from the Caribbean region, inhabiting epipelagic, bottom neritic and deep-water areas.
- 2.2. The Ts values of collagen of fishes from epipelagic areas are known to be higher than those of representatives from other areas; for deep-water fishes these values are the lowest.
- 3.3. It has been shown that Ts values may furnish additional information both about the fishes' temperature ecology and the depths of their habitat.
9.
《Journal of thermal biology》1986,11(1):67-72
- 1.1.|Operative environmental temperature (Tc) is commonly measured using a taxidermic mount consisting of a hollow copper cast of an animal's body covered by the animal's integument. We compare estimates of Tc made using such mounts with those derived from use of painted metal sphere thermometers, which are easier to construct and more rugged than taxidermic mounts.
- 2.2.|Comparison of data for 4 bird species indicates that metal spheres may be acceptable Tc-thermometers for analyses involving multiple measurements over moderately long time-scales (e.g. several hours).
- 3.3.|In this case, positive and negative differences between operative temperature estimated from use of taxidermic mounts and painted spheres tend to compensate and the average difference is usually less than 2°C. This difference is similar to that resulting from postural variation of taxidermic mounts or variation among individual mounts in identical postures.
- 4.4.|Sensitivity analysis indicates that use of painted spheres is unlikely to be an important source of error in estimates of total daily energy expenditure.
- 5.5.|In contrast, use of painted sphere thermometers in analyses involving fewer measurements over shorter-time scales can produce unacceptable discrepancies from values obtained from taxidermic mounts (i.e. up to 6.3°C).
10.
《Journal of thermal biology》1986,11(3):151-156
- 1.1. Experimental evidence is presented that short-term thermoregulatory adjustments occurring not far from thermoneutrality, involve temperature changes that are opposite in sign in different body regions. In man, exposure to hot ambient temperature (Ta), induced a decrease in esophageal and rectal temperatures. In rabbit, exposure to cold Ta induced an increase in hypothalamic temperature.
- 2.2.|Similar results could be obtained by simulation on a mathematical model of man's thermoregulatory system.
- 3.3.|The above results, as well as analogues results described in the literature, can be accounted for by a scheme of interpretation standing on current concepts of thermoregulation. If the gain of the thermoregulatory system is high, thermal stimulation of a region of the body will induce opposite temperature changes in other regions of the body.
11.
《Comparative biochemistry and physiology. C: Comparative pharmacology》1988,89(2):399-402
- 1.1. Optimum in vitro conditions, and kinetics of the enzyme catechol-O-methyltransferase from the brain of the male African catfish were studied.
- 2.2. A saturated level for S-adenosylmethionine, as methyldonor, and magnesium as cofactor was reached at 5 μM and 10 mM, respectively.
- 3.3. The addition of ascorbic acid, as an antioxidant, and tranylcypromine, as a MAO inhibitor, was not necessary, during incubations with fore-brain homogenates.
- 4.4. Kinetic analysis of the methylation of catecholestrone, catecholestradiol and dopamine showed Km values of 1.2, 0.6 and 0.5 μM, respectively.
- 5.5. The affinity of the catecholsubstrates for the enzyme catechol-O-methyltransferase is much higher in the brain of the African catfish than in tissues of mammals.
12.
《Comparative biochemistry and physiology. A, Comparative physiology》1993,104(4):823-830
- 1.1. Indian River male broiler chickens growing from 7 to 28 days of age were fed diets containing 12, 18, 24 and 30% protein + 0 or 1 mg triiodothyronine (T3)/kg of diet to study energetic costs of lipogenesis and the use of various substrates for in vitro lipogenesis.
- 2.2. De novo lipid and CO2 production were determined in the presence of [1-14C]pyruvate, [2-14q]pyruvate, [3-14C]pyruvate, [2-14C]acetate and [U-14C]alanine.
- 3.3. Oxygen consumption was determined in mitochondrial preparations to estimate the energetic costs in expiants synthesizing lipid.
- 4.4. Radiolabeled CO2 derived from [1-14C]pyruvate was used as an estimate of coenzyme A availability in liver expiants. Lipids derived from [2-14C]pyruvate, [2-14C]acetate and [U-14C]alanine estimate relative substrate efficiency.
- 5.5. Labeled CO2 production from [1-14C]pyruvate was greatest in that group fed a 12% protein diet and least in the group fed a 30% protein diet.
- 6.6. In addition, T3 increased CO2 production from [1-14C]pyruvate.
- 7.7. The production of 14CO2 from the second carbon of pyruvate or acetate was increased by T3.
- 8.8. The low-protein diet (12% protein) increased (P <0.05) lipogenesis.
- 9.9. Adding T3 to the diets decreased carbon flux into lipid from all substrates, but increased CO2 production from all substrates without changing stage 3 and 4 respiration rates in mitochondrial preparations.
- 10.10. These observations imply that coenzyme A availability may have regulated de novo lipogenesis in the present study.
- 11.11. It was also concluded that previously noted effects of T3 on intermediary metabolism may involve metabolic pathways that do not involve changes in mitochondrial function.
13.
《Comparative biochemistry and physiology. A, Comparative physiology》1981,68(1):111-114
- 1.1. The effect of short-term (79 hr) food deprivation at 27°C on body mass, locomotor activity, body temperature (Tb), and resting oxygen consumption was determined in eleven American kestrels (Falco sparverius).
- 2.2. The change in body mass during resting followed the relation, % mass remaining = 99 e0.07(days fasting). There was no significant difference in the rate of relative mass loss between males and females.
- 3.3. Locomotor activity, measured as perch hopping, was highly variable in both control and fasted birds and showed no correlation with stage of the fast, basal metabolic rate (BMR), or rate of mass loss during food deprivation.
- 4.4. Body temperatures of fasted birds declined continuously by 0.2–0.4°C per day from 39.3 to 38.3°C.
- 5.5. Both males and females responded to food deprivation with a decrease in metabolism. By the third night of fasting, BMR had declined 23.4% from 0.845 W (bird day)−1 to 0.647 W (bird day)−1. The observed reduction in BMR is 2.4 times that expected from a 1°C decline in Tb (assuming Q10 = 2.5) indicating active suppression of metabolism.
14.
- 1.1. Brain (hypothalamic), skin and body temperatures were measured in hand-reared acclimated (Acc, n = 5) and non-acclimated (NAcc, n =7) rock pigeons (Columba livia, mean body mass 237 g) exposed to increasing ambient temperatures (Ta) (30–60°C) and low humidities.
- 2.2. In non-panting Acc birds, brain temperature gradually increased from 40.1 ± 0.4°C at 30°C to 41.2 ± 0.4°C at 60°C Ta. A mean body temperature (Tb) of 41.2 ± 0.2°C was measured at Ta up to 50°C; an increase of 1.1°C was observed at 60°C (Tb 42.2 ±0.6°C).
- 3.3. In Acc panting birds exposed for 2 hr to 60°C, Thy was 41.9 ± 0.8°C and Ts was somewhat (but insignificantly) higher, i.e., 42.2 ± 0.7°C. It looks as if both values were increased as a result of a slight hyperthermia that developed (Tb = 43.5 ± 0.9°C).
- 4.4. The significance of the present results for evaluating neuronal thermoresponsiveness of birds' hypothalamus is discussed.
15.
《Comparative biochemistry and physiology. A, Comparative physiology》1986,83(3):489-493
- 1.1. Fundamental chitin digestion characteristics of Crassostrea virginica crystalline style were investigated.
- 2.2. Optimum temperature and pH were 34°C and 4.8. respectively.
- 3.3. The colloidal regenerated chitin (0.56mol/0.5 ml: GlcNAc equivalents) was saturating under all enzyme levels encountered.
- 4.4. There was no evidence of end product inhibition, even after 100 hr incubation.
- 5.5. Calculated Km for the chitinase complex was 1.19mM when determined using a 30 min assay, but was only 0.70 mM when determined using a 4.6 hr assay.
- 6.6. Both Km values are lower than reported for similar assays in other molluscs and for most bacteria.
- 7.7. Effect of substrate preparation on the kinetics are discussed.
- 8.8. Eight peaks of chitinase activity were resolved by DEAE-Fractogel ion exchange chromatography.
16.
《Journal of thermal biology》2005,30(1):37-41
- 1.Male Uca pugilator whose major cheliped was immersed in 3 °C water bath experienced a significant drop in Tb. Thus, the enlarged claw of male Uca pugilator may have an unexplored function: thermoregulation.
- 2.Crabs prefer warmer substrates (19–24 and 28–30 °C) over cooler (15–17 °C).
- 3.Mean selected temperature (MST) may not be an accurate reflection of Tb. Crabs in a thermal chamber preferred temperatures between 25 and 30 °C but their average Tb was 23.2 °C.
17.
《Comparative biochemistry and physiology. A, Comparative physiology》1987,86(2):201-206
- 1.1. Heart rate (HR) was measured during and after stress and activity in the armoured legless lizard Ophisaurus apodus, the snake Natrix natrix and the tortoise Testudo hermanni, at different body temperatures Tb. These are discussed in relation to field Tb, defensive behaviour and published V́O2.
- 2.2. Ophisaurus apodus used passive defence, including hemipenis or cloacal sac eversion and prolonged immobility after release. This was correlated with a low degree of tachycardia, bradycardia at low Tb, low metabolism and armour.
- 3.3. Defence behaviour was Tb-dependent in wild T. hermanni, with passive withdrawal into the shell at low Tb, and active struggling at high Tb. The degree of tachycardia was lower at low Tb.
- 4.4. Standard and active oxygen pulse OP were insensitive to Tb in O. apodus and N. natrix, and their SOP was lower than tetrapod lizards. Factorial scope of HR was reduced at 35°C, just above the activity Tb range of these species.
- 5.5. Recovery of HR after activity in T. hermanni was much more rapid than in the squamates, and of similar duration to recovery after stress. It is suggested that tortoises do not utilize anaerobic metabolism during activity.
18.
《Comparative biochemistry and physiology. A, Comparative physiology》1987,86(2):183-186
- 1.1. Thirty-one male golden-mantled ground squirrels were divided into four physiological groups: low wt summer, medium wt summer, high wt summer and hibernation period. A second group of 10 females was divided into two groups: hibernation period at low Tb and hibernation period during a periodic arousal.
- 2.2. Blood serum, pancreas and antral stomach region were collected from each animal.
- 3.3. The serum was analysed by radioimmunoassay for pancreatic polypeptide immunoreactivity, the pancreas for pancreatic polypeptide and somatostatin immunoreactivity and the antral region of the stomach for gastrin immunoreactivity.
- 4.4. Significant between-stage differences (P < 0.05) were found in serum pancreatic polypeptide concentration and in pancreatic somatostatin content.
19.
《Journal of thermal biology》2005,30(7):503-510
- 1.The levels of water, Na, K, Ca and Mg in blood serum, brain and kidney and aldosterone level in blood of Naja haje haje were studied during the different phases of the annual cycle.
- 2.The water content in the tissues studied displayed only minor changes as the animals passed from one phase to the other.
- 3.A significant increase in Na was recorded in the brain during the different phases indicating a depressed sodium pump, whereas the blood Na level showed a significant decrease during hibernation.
- 4.K increased in blood serum, brain and kidney during hibernation, while a nonsignificant decrease was found in blood serum during arousal. The brain may act as a potassium reservoir.
- 5.An increase in Ca and Mg concentration was recorded in blood serum, brain and kidney during prehibernation and hibernation. The data suggested a homeostatic function in the transport and metabolism of these cations.
- 6.Aldosterone exhibited a highly significant decrease especially during hibernation. The aldosterone regulation of ionic composition is discussed.
- 7.Na/K and Ca/Mg ratios in the brain may explain the decreased excitability during winter torpor.
20.
《Comparative biochemistry and physiology. A, Comparative physiology》1979,62(2):309-316
- 1.1. Comparisons of electrophysiological responses (ERG) were made between two different in vitro preparations of teleost retina.
- 2.2. The ERG was independent of temperature over the normal environmental range.
- 3.3. The Q10 demonstrated temperature independence between 5 and 20°C.
- 4.4. The electrical response of the isolated retina was found to be independent of partial pressures of oxygen at levels above 250 mm Hg.