Ulibarri C, Micevych P E
Department of Anatomy and Cell Biology, UCLA School of Medicine 90024-1763.
Physiol Behav. 1993 Jul;54(1):95-100. doi: 10.1016/0031-9384(93)90049-l.
Microinjections of sulphated cholecystokinin octapeptide (sCCK-8) into the ventromedial nucleus of the hypothalamus inhibit lordosis behavior in receptive female rats. This effect of sCCK-8 seems to differentiate under the control of gonadal steroids shortly after birth. Neonatally castrated males and normal females show similar responses, while androgenized females are less sensitive to sCCK-8. The current study investigated estrogen's role on the differentiation of the response to sCCK-8. On the day of birth male rat pups were castrated, given sham surgeries, or implanted with the antiestrogen tamoxifen or the aromatase inhibitor androst-1, 4, 6-triene-3, 17-dione (ATD). Females were implanted with testosterone propionate or tamoxifen, or given sham surgeries. Implants were removed 10 days later. As adults, rats were tested for female sexual behavior after microinjections of sCCK-8 into the ventromedial nucleus of the hypothalamus. Neonatally castrated males, ATD-treated males, and control females showed profound inhibition of lordosis behavior after sCCK-8. These results suggest that elimination of estrogen postnatally prevents defeminization of the reproductive circuitry that responds to sCCK-8.
向接受性雌性大鼠的下丘脑腹内侧核微量注射硫酸化胆囊收缩素八肽（sCCK - 8）会抑制其脊柱前凸行为。sCCK - 8的这种作用似乎在出生后不久受性腺类固醇的控制而有所分化。新生期阉割的雄性大鼠和正常雌性大鼠表现出相似的反应，而雄激素化的雌性大鼠对sCCK - 8的敏感性较低。本研究调查了雌激素在对sCCK - 8反应分化中的作用。在出生当天，雄性幼鼠接受阉割、假手术，或植入抗雌激素他莫昔芬或芳香化酶抑制剂雄甾 - 1,4,6 - 三烯 - 3,17 - 二酮（ATD）。雌性大鼠植入丙酸睾酮或他莫昔芬，或接受假手术。10天后取出植入物。成年后，向大鼠下丘脑腹内侧核微量注射sCCK - 8后检测其雌性性行为。新生期阉割的雄性大鼠、接受ATD处理的雄性大鼠和对照雌性大鼠在注射sCCK - 8后脊柱前凸行为受到显著抑制。这些结果表明，出生后消除雌激素可防止对sCCK - 8产生反应的生殖神经回路的去雌性化。
