Badura L L, Goldman B D
Department of Physiology and Neurobiology, University of Connecticut, Storrs 06269.
Neuroendocrinology. 1994 Jan;59(1):49-56. doi: 10.1159/000126637.
The role of the hypothalamic paraventricular nucleus (PVN) region in the control of seasonal prolactin (PRL) responses was investigated in female Siberian hamsters via disruption of PVN afferent connections from the region of the suprachiasmatic nucleus (SCN). Adult female hamsters received sham surgery or horizontal knife cuts placed ventral to the PVN so as to sever dorsally projecting fibers from the SCN and were either immediately transferred to a short-day photoperiod [10 h light:14 h dark (10L:14D); experiment (exp.) 1A] or returned to the long-day photoperiod (16L:8D; exp. 1B and 2). Serial blood samples were analyzed for determination of circulating PRL and follicle-stimulating hormone (FSH; exp. 1A) levels at various time points after surgery. In exp. 1A, sham-operated animals showed a steady decline in circulating levels of both PRL and FSH during exposure to 10L. Animals with knife cuts that passed through the extent of the SCN were prevented from showing declines in PRL and FSH during exposure to 10L. Animals with knife cuts located ventral to or through the PVN but dorsal to the SCN maintained high FSH levels during short-day exposure but showed a decline in PRL. Similarly, animals with knife cuts in exp. 1B and 2 showed a decline in circulating PRL despite continued exposure to a stimulatory photoperiod. In exp. 2, the efficacy of a dopaminergic agonist (CB154) and an antagonist (pimozide) in altering circulating PRL under the 16L photoperiod was evaluated. CB154 induced declines in PRL in knife-cut but not sham-operated animals, whereas administration of pimozide elevated circulating PRL in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)
通过破坏来自视交叉上核（SCN）区域的下丘脑室旁核（PVN）传入连接，研究了雌性西伯利亚仓鼠下丘脑室旁核（PVN）区域在季节性催乳素（PRL）反应控制中的作用。成年雌性仓鼠接受假手术或在PVN腹侧进行水平刀切割，以切断来自SCN的背向投射纤维，然后立即转移到短日照光周期[10小时光照：14小时黑暗（10L：14D）；实验（exp.）1A]或返回长日照光周期（16L：8D；实验1B和2）。在手术后的不同时间点采集系列血样，分析循环中的PRL和促卵泡激素（FSH；实验1A）水平。在实验1A中，假手术动物在暴露于10L期间，循环中的PRL和FSH水平稳步下降。穿过SCN范围的刀切割动物在暴露于10L期间，PRL和FSH水平未下降。位于PVN腹侧或穿过PVN但在SCN背侧的刀切割动物在短日照暴露期间保持高FSH水平，但PRL水平下降。同样，实验1B和2中的刀切割动物尽管持续暴露于刺激性光周期，循环中的PRL水平仍下降。在实验2中，评估了多巴胺能激动剂（CB154）和拮抗剂（匹莫齐特）在16L光周期下改变循环PRL的效果。CB154诱导刀切割动物而非假手术动物的PRL下降，而给予匹莫齐特使两组动物的循环PRL升高。（摘要截短于250字）
