Torres G, Haak K A, Lytle L D
Department of Psychology, University of California, Santa Barbara 93106.
J Pineal Res. 1989;6(1):43-53. doi: 10.1111/j.1600-079x.1989.tb00401.x.
The newly born of many mammalian species are ectothermic, and it is possible that biochemical processes important for the metabolism of endocrine hormones might vary with alterations in the environmental temperature. Temperature-induced fluctuations in pineal gland N-acetyltransferase activity were investigated in 4-, 12-, and 20-day-old rats placed for 4 hr in 23 or 34 degrees C environments. Enzyme activity increased dramatically in ectothermic 4- and 12-day-old animals exposed to the 23 degrees C environment, but not in endothermic 20-day-old rats. The elevations in daytime pineal gland NAT activity seen in cold-exposed animals were absent in rats previously subjected to chemical sympathectomy induced by 6-hydroxydopamine, or in animals treated with the beta-noradrenoceptor antagonist drug propranolol. Catecholaminergic nerves and beta-noradrenoceptors known to be important for light-induced changes in mammalian pineal gland biochemistry also appear essential for environmental temperature-dependent elevations in neonatal pineal N-acetyltransferase activity.
许多哺乳动物物种的新生幼崽是变温动物，对于内分泌激素代谢很重要的生化过程可能会随环境温度的变化而改变。研究了4日龄、12日龄和20日龄大鼠在23或34摄氏度环境中放置4小时后，松果体N - 乙酰转移酶活性因温度诱导的波动情况。在暴露于23摄氏度环境的变温4日龄和12日龄动物中，酶活性显著增加，但在恒温20日龄大鼠中则没有。在先前接受过6 - 羟基多巴胺诱导的化学交感神经切除术的大鼠中，或在用β - 去甲肾上腺素能受体拮抗剂普萘洛尔治疗的动物中，寒冷暴露动物白天松果体NAT活性的升高并未出现。已知对哺乳动物松果体生化的光诱导变化很重要的儿茶酚胺能神经和β - 去甲肾上腺素能受体，对于新生儿松果体N - 乙酰转移酶活性的环境温度依赖性升高似乎也至关重要。
