Yamamoto H, Nagai K, Nakagawa H
Endocrinology. 1985 Aug;117(2):468-73. doi: 10.1210/endo-117-2-468.
The role of the suprachiasmatic nucleus (SCN) of the hypothalamus in the glucagon response to intracranial injection of 2-deoxy-D-glucose (2DG) was examined using rats with lesions involving the SCN under 12-h light (0800-2000 h), 12-h dark (2000-0800 h) illumination. In sham-operated rats, 2DG injection into the lateral cerebral ventricle caused rapid increase in the plasma glucagon level, which was associated with increase in the plasma glucose concentration in both the light and dark period. The glucagon responses to 2DG injection in the light and dark periods were similar. In contrast, lesions involving the SCN not only reduced the plasma glucagon level before 2DG injection but also completely eliminated the glucagon response to 2DG injection, which was not associated with a rise in plasma glucose concentration. Under free feeding conditions, plasma insulin level was higher and lower in rats with the lesions involving the SCN than that in controls at 1400 h and 0200 h, respectively, but the glucagon level was lower in rats with the lesions than that in controls both at 1400 h and 0200 h. These findings suggest that the area including bilateral SCN has a regulatory (stimulatory) action on glucagon secretion from the pancreas and is involved in the glucagon response to 2DG injection into the lateral cerebral ventricle.
在12小时光照（08:00 - 20:00）、12小时黑暗（20:00 - 08:00）的光照条件下，利用视交叉上核（SCN）受损的大鼠，研究下丘脑视交叉上核在胰高血糖素对颅内注射2 - 脱氧 - D - 葡萄糖（2DG）反应中的作用。在假手术大鼠中，向侧脑室注射2DG会导致血浆胰高血糖素水平迅速升高，这与光照期和黑暗期血浆葡萄糖浓度的升高相关。在光照期和黑暗期，胰高血糖素对2DG注射的反应相似。相比之下，涉及SCN的损伤不仅降低了注射2DG前的血浆胰高血糖素水平，还完全消除了胰高血糖素对2DG注射的反应，且这与血浆葡萄糖浓度的升高无关。在自由进食条件下，在14:00和02:00时，涉及SCN损伤的大鼠血浆胰岛素水平分别高于和低于对照组，但在14:00和02:00时，损伤大鼠的胰高血糖素水平均低于对照组。这些发现表明，包括双侧SCN的区域对胰腺胰高血糖素分泌具有调节（刺激）作用，并参与了对侧脑室注射2DG的胰高血糖素反应。
