Ottenweller J E, Meier A H
Endocrinology. 1982 Oct;111(4):1334-8. doi: 10.1210/endo-111-4-1334.
The daily rhythm of plasma corticosteroid concentration was studied in nonhypophysectomized rats and in hypophysectomized rats implanted with beeswax pellets containing ACTH and T4. In the first experiment, male hypophysectomized rats were placed on a 12-h light, 12-h dark cycle (onset of light, 0600 h) with food and water available ad libitum. Beeswax pellets containing 1.5 mg ACTH and 150 micrograms T4 were implanted sc in these rats. Beginning 4 days after the implantation of ACTH and T4, daily rhythms of plasma corticosteroid concentration were detected in these rats on 3 successive days. The injection of sodium pentobarbital (40 mg/kg BW) or atropine sulfate (10 mg/kg BW) ip at 1200 h blocked the expected rise in plasma corticosteroid concentration at 1800 h in both these rats and a group of intact rats. In the second experiment, adrenal innervation was disrupted by spinal cord transection at the T-7 level. L-1-transected rats served as operated controls, and a third group was maintained as unoperated controls. One week after surgery, daily rhythms of plasma corticosteroid concentration were present in both unoperated and L-1 controls (P less than 0.01) but not in the T-7-transected rats. Inasmuch as an extrapituitary mechanism was capable of maintaining adrenocortical rhythmicity in hypophysectomized rats and disruption of adrenal innervation suppressed adrenocortical rhythmicity, it was hypothesized that adrenal innervation may be an extrapituitary mechanism which has a role in adrenocortical rhythmicity.
在未切除垂体的大鼠以及植入含促肾上腺皮质激素（ACTH）和甲状腺素（T4）的蜂蜡丸的切除垂体的大鼠中，研究了血浆皮质类固醇浓度的日节律。在第一个实验中，将雄性切除垂体的大鼠置于12小时光照、12小时黑暗的周期（光照开始于06:00），食物和水可随意获取。将含1.5毫克ACTH和150微克T4的蜂蜡丸皮下植入这些大鼠。在植入ACTH和T4 4天后开始，连续3天检测这些大鼠血浆皮质类固醇浓度的日节律。在12:00腹腔注射戊巴比妥钠（40毫克/千克体重）或硫酸阿托品（10毫克/千克体重），可阻断这些大鼠以及一组完整大鼠在18:00时血浆皮质类固醇浓度预期的升高。在第二个实验中，通过在T-7水平横断脊髓来破坏肾上腺神经支配。L-1横断的大鼠作为手术对照组，第三组作为未手术对照组。手术后一周，未手术和L-1对照组均存在血浆皮质类固醇浓度的日节律（P<0.01），但T-7横断的大鼠中不存在。由于一种垂体外机制能够维持切除垂体大鼠的肾上腺皮质节律性，且肾上腺神经支配的破坏会抑制肾上腺皮质节律性，因此推测肾上腺神经支配可能是一种在肾上腺皮质节律性中起作用的垂体外机制。
