El Halawani M E, Waibel P E
Am J Physiol. 1976 Jan;230(1):110-5. doi: 10.1152/ajplegacy.1976.230.1.110.
Turnovers of dopamine (DA), norepinephrine (NE), epinephrine (E), and 5-hydroxytryptamine (5-HT) were determined in the brains of male turkeys during acute, chronic, and posttemperature stress. Changes induced in the depletion of endogenous monoamine levels 6 h after tyrosine hydroxylase or tryptophan hydroxylase inhibitions were regarded as changes in turnovers. High or low ambient temperature had no effect on brain DA turnover, whether the temperature stress was acute (6 h) or chronic (5 wk). Brain NE turnover increased upon acute exposure to either a cold (5 degrees C) or warm (32 degrees C) environment. Chronic exposure (5 wk) to such temperatures reduced significantly (P less than 0.001) the elevated NE turnover. The central E and 5-HT turnovers of birds kept at 32 degrees C for 6 h decreased and increased, respectively, whereas determination of E and 5-HT of birds kept at 5 degrees C showed an opposite pattern. Five weeks of continuous exposure to high and low environmental temperatures did not alter the changes in E and 5-HT turnovers from those observed during acute stress. Exposure of heat- or cold-reared turkeys to 24 degrees C reversed the changes in E and 5-HT turnovers. Thus the results indicated an increase in NE turnover only during acute exposure to thermal stress. However, the changes in E and 5-HT turnovers persisted during chronic exposure.
在急性、慢性和温度应激后，测定了雄性火鸡大脑中多巴胺（DA）、去甲肾上腺素（NE）、肾上腺素（E）和5-羟色胺（5-HT）的周转率。酪氨酸羟化酶或色氨酸羟化酶抑制6小时后内源性单胺水平的消耗变化被视为周转率的变化。无论温度应激是急性（6小时）还是慢性（5周），高或低环境温度对大脑DA周转率均无影响。急性暴露于寒冷（5摄氏度）或温暖（32摄氏度）环境中时，大脑NE周转率增加。长期暴露（5周）于此类温度会显著降低（P<0.001）升高的NE周转率。在32摄氏度下饲养6小时的鸟类，其大脑E和5-HT周转率分别降低和升高，而在5摄氏度下饲养的鸟类，E和5-HT的测定结果则呈现相反的模式。连续五周暴露于高、低环境温度下，E和5-HT周转率的变化与急性应激期间观察到的变化没有改变。将热饲养或冷饲养的火鸡暴露于24摄氏度下，可逆转E和5-HT周转率的变化。因此，结果表明仅在急性暴露于热应激期间NE周转率增加。然而，在慢性暴露期间，E和5-HT周转率的变化持续存在。
