Vitale P M, Darrow J M, Duncan M J, Shustak C A, Goldman B D
J Endocrinol. 1985 Sep;106(3):367-75. doi: 10.1677/joe.0.1060367.
During the autumn and winter Djungarian hamsters (Phodopus sungorus) exhibit regression of the gonads, development of a white winter pelage, loss of body weight and daily torpor. These seasonal events are largely regulated by changes in photoperiod. The present experiments were designed to examine the role of the testes and the pineal gland in photoperiodically induced daily torpor and body weight loss. Hamsters displayed a loss of body weight and daily torpor when exposed to a short-day photoperiod in a cold environment, but these phenomena did not occur in hamsters exposed to long days and cold. Testicular regression is probably a precondition for the display of torpor, since daily torpor was almost totally inhibited in hamsters which were exposed to short days and in which testosterone was administered from subcutaneous silicone elastomer implants. Nevertheless, decreased testosterone secretion alone is not a sufficient condition for induction of daily torpor, since torpor was rarely observed in hamsters exposed to long days, even after castration. In addition to decreased testicular activity, the pineal gland is also involved in establishing conditions for torpor. Thus, pinealectomy prevented the display of torpor by castrated hamsters exposed to short days. Body weight changes were also found to be influenced by both testicular hormone and pineal activity. These observations indicate that the pineal gland is involved, as a part of the photoperiodic mechanism, in regulating a variety of physiological events and that some of these actions of the pineal are independent of its extensively described actions on the reproductive axis.
在秋冬季节，黑线毛足鼠（Phodopus sungorus）会出现性腺退化、白色冬毛生长、体重减轻以及每日蛰伏现象。这些季节性变化主要受光周期变化的调节。本实验旨在研究睾丸和松果体在光周期诱导的每日蛰伏和体重减轻中的作用。当仓鼠在寒冷环境中暴露于短日照光周期时，会出现体重减轻和每日蛰伏现象，但在暴露于长日照和寒冷环境的仓鼠中则不会出现这些现象。睾丸退化可能是出现蛰伏的一个前提条件，因为在暴露于短日照且通过皮下硅橡胶弹性体植入物给予睾酮的仓鼠中，每日蛰伏几乎完全受到抑制。然而，仅睾酮分泌减少并不是诱导每日蛰伏的充分条件，因为即使在阉割后，暴露于长日照的仓鼠中也很少观察到蛰伏现象。除了睾丸活动减少外，松果体也参与了蛰伏条件的建立。因此，松果体切除术可防止暴露于短日照的阉割仓鼠出现蛰伏现象。体重变化也被发现受睾丸激素和松果体活动的影响。这些观察结果表明，松果体作为光周期机制的一部分，参与调节多种生理事件，并且松果体的一些作用独立于其对生殖轴的广泛描述的作用。
