太平鸟和灰头鹀的代谢产热特征及体温调节

采用封闭式流体压力呼吸仪,测定了在环境温度5、10、15、16、18、20、22、25、26、28和30℃时,捕自黑龙江省齐齐哈尔市的太平鸟(Bombycillagarrulus,1♀、7♂)和灰头(Emberizaspodocephala,8♂)的代谢率(MR),计算每个温度点的热传导(C)、MR和C的体重预期值。结果显示:在环境温度(Ta)为5~30℃时,太平鸟的体温(Tb)基本维持恒定,平均Tb为(38·20±0·05)℃;热中性区(TNZ)为18~27℃,基础代谢率(BMR)为(2·33±0·47)mLO2/(g·h);Ta在5~18℃,MR与Ta呈负相关,回归方程为:MR=5·46(±0·19)-0·17(±0·01)Ta;Ta在5~22℃,C最低且基本保持恒定,平均为(0·13±0·00)mLO2/(g·h·℃)。5~30℃时,灰头Tb也基本维持恒定,平均Tb为(38·25±0·05)℃;TNZ为20~26℃,BMR为(4·75±0·18)mLO2/(g·h),最低C为(0·26±0·00)mLO2/(g·h·℃);在5~20℃时,MR与Ta的回归方程为:MR=9·54(±0·52)-0·23(±0·03)Ta。两种鸟具有BMR和Tb较高、下临界温度较低和TNZ较宽、热传导稍高的北方地区小型鸟类的代谢特点,通过自身的物理和化学调节(代谢产热)以更好地适应其生存环境。     

Thermoregulatory use of heat increment of feeding in the tawny owl (Strix aluco)

The heat increment of feeding (HIF) was investigated in the tawny owl (Strix aluco) in central Norway (63°N, 10°E), close to the northern limit of its distribution. HIF was measured as the increase in heat production (measured as oxygen consumption) after force-feeding the owls with laboratory mice at thermoneutral conditions (20 °C) and during cold-exposure (5 °C and −5 °C). The basal metabolic rate of the owls (mean mass 419 g) was 4.39 kJ h⁻¹ and the lower critical temperature was approximately 16 °C. During cold conditions, HIF substituted for thermogenesis, and at an ambient temperature of −5 °C the substitution was complete. Calculations indicate that the substitution by HIF may save the owls as much as 60% of their daily thermoregulatory costs. This corresponds to about 10% of their total daily energy budget.     

β-Adrenoreceptor participation in the formation of the thermoregulatory and immune responses under the effect of rapid deep cooling

The effect of β-adrenoantagonist (obzidan) iontophoresis to skin on the thermoregulatory response and immune response to antigen was analyzed to elucidate the significance of β-adrenoceptors in formation of these responses at deep rapid cooling in rats.

On the background of β-adrenoceptors blockade in thermoneutral conditions the skin and core temperatures decreases; at rapid cooling non-shivering thermogenesis is attenuated and shivering thermogenesis is considerably enhanced.

Administration of β-adrenoantagonist affect the modulating influence of cold exposure on the immune response—the immunosuppressive effect of deep cooling on the immune response is abolished. This concerns both antigen binding function of spleen and peritoneal cells and antibody formation.

The results support the idea that β-adrenoceptors participates in the processes of the stimulation of thermogenesis and suppression of the immune response to antigen at rapid deep cooling.     

实验围栏内越冬眼镜蛇体温调节和低温耐受性的无线电遥测

用SB 2T内置热敏无线电发射器、HOBO和TINYTALK数据记录块等电子设备研究实验室围栏内越冬眼镜蛇 (Najaatra)的体温调节和低温耐受性。围栏内总平均气温 (10 6℃ )与总平均巢温 (10 9℃ )无显著差异 ,但气温变化幅度 (- 2 0～ 37 4℃ )大于巢温变化幅度 (6 5～ 14 5℃ )。眼镜蛇体温变化幅度 (3 4～34 1℃ )介于气温和巢温的变化幅度之间 ,平均体温的个体间差异显著 ,总平均体温 (15 0℃ )大于平均气温和平均巢温。最低体温的平均值为 8 9℃ ,与经验估测的眼镜蛇低温耐受极限 (9 0℃ )相近。白天气温高于15℃时能见到巢外调温个体 ,其体温记录次数约占处于此条件下的个体总体温记录次数的 2 9%。巢外调温个体的体温高于处于晚间和白天 15℃以下气温个体的体温 ,亦高于处于白天 15℃以上气温但不进行巢外调温个体的体温。处于白天 15℃以下气温个体的体温低于晚间个体的体温。处于白天 15℃以上气温但不进行巢外调温个体的体温与处于晚间和白天 15℃以下气温个体的体温无显著差异。处于晚间和白天 15℃以下气温个体的体温与气温呈显著的正相关 ,表明眼镜蛇在低温和缺乏热斑块的环境中是体温调节的顺应者。气温高于 15℃时 ,进行巢外调温和不进行巢外调温个体的体温均与气温无关 ,表明眼镜蛇在气温     

Heat tolerance of short-beaked echidnas (Tachyglossus aculeatus) in the field

(1) Echidnas occur throughout the hot arid zone of Australia yet laboratory studies have concluded that they are ill equipped physiologically to manage T_a higher than 35°C. (2) Consequently, it is generally assumed that echidnas must rely on behavioural thermoregulation, being nocturnal in hot weather and seeking less extreme microclimates during the day. (3) By monitoring T_b of echidnas in the field and relating these to T_a within their day time shelters in Western Queensland during summer, this study showed that echidnas are able to tolerate T_a of 35–40°C in hollow logs for up to 10 h. (4) Further, as T_b remains < T_a in these situations, echidnas may have physiological mechanisms for dealing with the heat after all.     

棕眉山岩鹨的代谢产热特征的初步研究

实验采用封闭式流体压力呼吸计和数字式温度计 ,分别测定了环境温度 (Ta)在 5～ 35℃范围内棕眉山岩鹨 (Prunellamontanella)的耗氧量和体温 (Tb) ,由此计算出代谢率 (MR)、热传导率 (C)和代谢预期比与热传导预期比 (F)等值 ,以探讨该种的代谢产热特征。结果表明 :棕眉山岩鹨在Ta 为 5～ 35℃时 ,Tb 基本维持恒定 (为 4 1 2 5± 0 12℃ ) ,MR的最低值为 4 2 7± 0 0 7mLO2 /(g·h) ;Ta 在 5～ 2 4℃时 ,MR与之负相关 :MR [mLO2 /(g·h) ]=10 39- 0 2 4Ta℃ ;Ta 在 5～ 2 6 5℃时 ,C最低且基本保持恒定 ,平均为 0 2 6±0 0 0mLO2 /(g·h·℃ ) ;Ta 在 2 4～ 30℃时 ,F值为 1 0 5 ,表明该种具有较好的体温调节能力。与热带地区鸟类比较 ,棕眉山岩鹨具较高的MR和Tb,稍高的C ,符合北方小型鸟类的代谢特点 ,能较好的适应冬寒冷、夏炎热的环境。     

Central blockade of nitric oxide synthesis induces hyperthermia that is prevented by indomethacin in rats

The effect of blocking brain nitric oxide (NO) synthesis on body temperature regulation was tested in conscious rats. NO synthase was inhibited by administration of equivalent doses of N^G-nitro-L-arginine methyl ester (L-NAME) or N^G-monomethyl L-arginine monoacetate (L-NMMA) into a lateral cerebral ventricle (ICV) and core temperature was monitored. An ICV injection of 300 μg L-NAME increased colonic temperature in rats (n=8) by 1.9±0.1 °C (P<0.001). The increase in temperature in response to blockade of NO synthesis was significant by 1 h after injection and sustained for more than 3 h. The hyperthermic response to central NO blockade (using L-NMMA) was found to be dose-dependent between 2.8 to 282 μg. Intravenous administration of L-NAME at the highest dose used in the study (300 μg) had no effect on temperature, indicating that the mechanism was mediated by the brain. Pre-treatment with indomethacin (300 μg) blocked hyperthermic responses to ICV L-NAME (300 μg) administration. We conclude that, blockade of nitric oxide induces a cyclooxygenase-dependent hyperthermia in conscious rats that is mediated by the brain.     

温度与聚群对三种仔兽热能代谢的影响

仔兽出生以前,是在相对稳定而安全的母兽子宫内生活的,出生以后,仔兽的营养条件与环境温度即起了根本的变化。新生仔兽是如何适应新环境的?仔兽在新环境中的生活能力怎样?环境温度与食物条件对新生仔兽的存活率、生长与发育的影响如何?环境温度和聚群行为与能量代谢的关系怎样?这是一系列的基础理论问题,尤其是毛皮动物饲养业所关心的实际问题。     

长爪沙鼠与黑线仓鼠的温度选择比较

本文使用自制的陆生动物温度选择仪,对长爪沙鼠和黑线仓鼠的温度选择进行了比较,结果表明,长爪沙鼠的选择温度(29.06±0.62℃)较黑线仓鼠(26.65±0.64℃)高。这种差异可能与两种鼠的栖息环境及昼夜节律的不同有关。     

Daily Rhythms of Metabolic Rate and Body Temperature of Two Murids from Extremely Different Habitats

Daily circadian rhythms of body temperature (T_b) and oxygen consumption (VO₂) were measured in two murid species, which occupy extremely different habitats in Israel. The golden spiny mouse (Acomys mssalus) is a diurnal murid distributed in arid and hot parts of the great Syrio-African Rift Valley, while the broad-toothed field mouse (Apodeinns mystacinus) is a nocturnal species that inhabits the Mediterranean woodlands. In both species, the daily rhythms of T_b and VO₂ are entrained by the photoperiod. Under laboratory experimental conditions (ambient temperature T_a = 33^oC and photoperiod regime of 12L: 12D), Acomys russatus exhibits a tendency towards a nocturnal activity pattern, compared to the diurnal activity displayed by this species under natural conditions. Under the same photoperiod regime and at T_a = 28^oC, Apodemus mystacinus displays nocturnal activity, as observed under natural conditions. The maximal values of T_b were recorded in Acomys russatus at midnight (23:50 h), while the maximal values of VO₂ were recorded at the beginning of the dark period (18:20 h). In Apodemus mystacinus, the maximal values of T_b and VO₂ were recorded at 23:40 and 20:00 h, respectively. The ecophysiological significance of these results is discussed further.