Averill R L
Proc Soc Exp Biol Med. 1986 Sep;182(4):478-82. doi: 10.3181/00379727-182-42369.
Anterior pituitary (AP) tissue grafted into the hypothalamus inhibited the luteotrophic response to mating and prevented pseudopregnancy (PSP) and pregnancy. All normal rats given 10 micrograms estradiol benzoate (EB) on estrus became PSP (15 days) while the same treatment caused 10-day PSPs in 20/21 grafted rats. Doses of 30 micrograms EB or 10 micrograms EB plus reserpine (1 mg/kg) resulted in 15-day PSP in grafted rats. By contrast progesterone (P; 10 mg on estrus) did not prolong cycles in rats with hypothalamic grafts though it did in 50% of normals. Earlier studies showed that PSP or pregnancy was restored in the grafted rats by blockade of dopamine (DA) secretion. The results above show that EB was similarly effective in restoring PSP while P was not, suggesting that EB both raised prolactin and lowered DA while P was unable to lower DA in rats with AP grafts in the hypothalamus.
移植到下丘脑的垂体前叶组织抑制了对交配的促黄体反应，并阻止了假孕（PSP）和怀孕。所有在发情期给予10微克苯甲酸雌二醇（EB）的正常大鼠都进入了假孕期（15天），而相同处理使20/21只移植大鼠出现了10天的假孕期。30微克EB或10微克EB加利血平（1毫克/千克）的剂量使移植大鼠出现了15天的假孕期。相比之下，孕酮（P；发情期10毫克）虽能使50%的正常大鼠延长周期，但对下丘脑移植大鼠却没有此作用。早期研究表明，通过阻断多巴胺（DA）分泌，可使移植大鼠恢复假孕或怀孕。上述结果表明，EB在恢复假孕期方面同样有效，而P则不然，这表明EB既能升高催乳素又能降低DA，而P在下丘脑有垂体前叶移植的大鼠中无法降低DA。
