Furudate S, Ashihara H, Nakano T
Department of Laboratory Animal Science, School of Medicine, Kitasato University, Kanagawa, Japan.
Jikken Dobutsu. 1989 Oct;38(4):313-8. doi: 10.1538/expanim1978.38.4_313.
Serum and pituitary prolactin (PRL) concentrations were measured during the estrous cycle of the rat with particular attention to the afternoons of the days of proestrus and estrus. Homogenizing machines, a Polytron and Sonifier, were used to extract PRL from the pituitary gland. The effects of ether anesthesia and restraint were also examined on the afternoons of both proestrus and estrus. The occurrence of a surge in PRL secretion during proestrus was confirmed with a peak at 1500 h, and this was accompanied by a decline in pituitary PRL content. A relatively high level of serum PRL was observed in the afternoon of estrus, during which time pituitary PRL content increased progressively. Ether anesthesia had no effect on the proestrus PRL surge, while restraint enhanced it. On the afternoon of estrus, restraint completely suppressed the rise in serum PRL, but ether anesthesia failed to suppress it completely. From these results, the following conclusions were drawn: 1) the PRL surge on the afternoon of proestrus occurs without synthesis of the hormone in the pituitary; 2) PRL secretion on the afternoon of estrus is accompanied by its synthesis in the gland; 3) the PRL response is distinct for each type of stress applied; and 4) PRL secretion is thus regulated by different mechanisms in proestrus and estrus.
在大鼠发情周期中测定血清和垂体催乳素（PRL）浓度，特别关注动情前期和发情期下午的情况。使用匀浆机（Polytron和Sonifier）从垂体中提取PRL。还在动情前期和发情期下午检查了乙醚麻醉和束缚的影响。确认在动情前期PRL分泌出现激增，在15:00达到峰值，同时垂体PRL含量下降。在发情期下午观察到血清PRL水平相对较高，此时垂体PRL含量逐渐增加。乙醚麻醉对动情前期PRL激增无影响，而束缚增强了该激增。在发情期下午，束缚完全抑制了血清PRL的升高，但乙醚麻醉未能完全抑制。从这些结果得出以下结论：1）动情前期下午的PRL激增是在垂体中不合成该激素的情况下发生的；2）发情期下午的PRL分泌伴随着其在腺体内的合成；3）对每种施加的应激类型，PRL反应是不同的；4）因此，PRL分泌在动情前期和发情期受不同机制调节。
