Kamoi K, Henry D P, Robertson G L
Endocrinology. 1984 Jun;114(6):2123-7. doi: 10.1210/endo-114-6-2123.
The supraoptic nuclei of the hypothalamus are known to be heavily innervated by noradrenergic neurons. However, the role of these neurons in regulating secretion of the antidiuretic hormone, arginine vasopressin, remains unsettled. In an effort to clarify this question, we studied the effect of multiple small doses of D,L alpha-methyl-p-tyrosine (alpha-MpT) on hypothalamic norepinephrine and the osmoregulation of vasopressin in rats. We found that, at the doses employed (80 mg/kg every 6 h for 24 h), alpha-Mpt reduced mean (+/- SD) hypothalamic norepinephrine by about 50% but did not affect plasma osmolality, sodium, glucose, urea, or vasopressin either under basal conditions or during osmotic stimulation by ip injection of hypertonic saline. During the latter, plasma vasopressin correlated directly with plasma osmolality and the regression lines that described the relationships in the control and drug-treated rats were identical. Hematocrit and mean arterial pressure were also unaffected by alpha-MpT. These findings do not support the concept based on previous studies that central noradrenergic pathways mediate the vasopressin response to osmotic stimuli.
已知下丘脑视上核接受去甲肾上腺素能神经元的大量支配。然而，这些神经元在调节抗利尿激素精氨酸加压素分泌中的作用仍未明确。为了阐明这个问题，我们研究了多次小剂量的D，Lα-甲基对酪氨酸（α-MpT）对大鼠下丘脑去甲肾上腺素以及加压素渗透调节的影响。我们发现，在所采用的剂量下（每6小时80mg/kg，共24小时），α-MpT使下丘脑去甲肾上腺素的平均（±标准差）水平降低了约50%，但在基础条件下或腹腔注射高渗盐水进行渗透刺激时，并未影响血浆渗透压、钠、葡萄糖、尿素或加压素。在后者情况下，血浆加压素与血浆渗透压直接相关，并且描述对照大鼠和药物处理大鼠中这种关系的回归线是相同的。血细胞比容和平均动脉压也不受α-MpT影响。这些发现不支持基于先前研究得出的观点，即中枢去甲肾上腺素能途径介导加压素对渗透刺激的反应。
