Currie I S, Gillies G, Brooks A N
MRC Reproductive Biology Unit, Centre for Reproductive Biology, Edinburgh, UK.
Neuroendocrinology. 1994 Oct;60(4):360-7. doi: 10.1159/000126770.
In sheep, arginine vasopressin (AVP) appears to be a more potent ACTH-releasing factor than ovine corticotrophin-releasing hormone. In order to investigate the neuroendocrine regulation of AVP secretion we have developed a novel system for maintaining fetal ovine hypothalamic neurones in serum-free culture. Hypothalamic neurones derived from fetal sheep at day 70 gestation (term = 145 days) secreted AVP under basal conditions and in response to repeated potassium-induced depolarizations, for up to 35 days in vitro. AVP secretion was time- and calcium-dependent. AVP secreted from ovine hypothalamic cells co-eluted with synthetic AVP on a Sephadex chromatography column and diluted in parallel with AVP standard in the radioimmunoassay. The addition of cortisol (150 nM) to medium bathing ovine hypothalamic cells significantly inhibited basal, and potassium-induced AVP secretion without altering the AVP content of the cell cultures. Furthermore, the opioid peptide [D-Pro10]Dynorphin(1-11) which acts via the kappa opioid receptor, significantly inhibited basal and potassium-stimulated AVP secretion, an effect which was abolished when cells were cultured in the presence of cortisol. These data show that hypothalamic AVP is a site for negative feedback regulation within the ovine hypothalamic-pituitary-adrenal axis. Furthermore, these data suggest that the kappa opioid system inhibits AVP secretion from ovine hypothalamic neurones, a response which is modulated by glucocorticoids.
在绵羊中，精氨酸加压素（AVP）似乎是一种比羊促肾上腺皮质激素释放激素更有效的促肾上腺皮质激素释放因子。为了研究AVP分泌的神经内分泌调节，我们开发了一种在无血清培养中维持胎羊下丘脑神经元的新系统。源自妊娠70天（足月为145天）的胎羊的下丘脑神经元在基础条件下以及对重复的钾诱导去极化作出反应时分泌AVP，在体外培养长达35天。AVP分泌具有时间依赖性和钙依赖性。从羊下丘脑细胞分泌的AVP与合成的AVP在葡聚糖凝胶色谱柱上共洗脱，并在放射免疫测定中与AVP标准品平行稀释。向培养羊下丘脑细胞的培养基中添加皮质醇（150 nM）可显著抑制基础和钾诱导的AVP分泌，而不改变细胞培养物中的AVP含量。此外，通过κ阿片受体起作用的阿片肽[D-Pro10]强啡肽（1-11）显著抑制基础和钾刺激的AVP分泌，当细胞在皮质醇存在下培养时，这种作用被消除。这些数据表明，下丘脑AVP是羊下丘脑-垂体-肾上腺轴内负反馈调节的一个位点。此外，这些数据表明，κ阿片系统抑制羊下丘脑神经元分泌AVP，这种反应受糖皮质激素调节。
