性腺甾体激素对雌,雄大鼠下丘脑血管升压素mRNA水平的影响

实验用１０－１１周龄经阉割的雌、雄Ｓｐｒａｇｕｅ－Ｄａｗｌｅｙ大鼠进行。以３末端异羟基洋地黄毒甙标记的２６个碱基长的寡核苷酸作为检测探针，用核酸斑点杂交技术检测大鼠下丘脑血管升压素ｍＲＮＡ水平。在假手术对照组，雄性大鼠下丘脑ＡＶＰｍＲＮＡ水平经雌性大鼠高４５％（Ｐ〈０．０５），血浆渗透压高于雌性大鼠（Ｐ〈０．０５）。摘除卵巢的大鼠下丘脑ＡＶＰｍＲＮＡ深恶痛绝经假手术组雌性大鼠高３０％（Ｐ〈０．０５

EFFECTS OF GONADAL STEROID HORMONES ON HYPOTHALAMIC VASOPRESSIN mRNA LEVEL IN MALE AND FEMALE RATS

Experiments were carried out in 10-11-week old gonadectomized male and female Sprague-Dawley rats. Dot-blot analysis and 31-end digoxigenin-labeled 26 meroligonucleotide probe was used in detecting the mRNA level hypothalamic vasopressin(AVP). The basal hypothalamic AVP-mRNA level in the sham-operated intact maleswas 45% higher than that in the sham-operated intact females (P<0. 05). Plasma osmolality was also higher in the sham-operated intact males than in the sham-operated intact females (P<0. 05). The hypothalamic AVP-mRNA level in ovariectomized ratswas 30% higher than that in sham-operated intact females (P<0. 05). Although thehypothalamic AVP mRNA level tended to be lower in castrated males than in sham-operated intact males, the difference was not statistically significant. The difference inplasma osmolality between gonadectomized males and females was statistically insignificant. In castrated males, hypothalamic AVP-mRNA level was decreased following sc injection of estradiol (P< 0. 05), but testosterone, progesterone or a combination ofestradiol and progesterone were without effect. In ovariectomized rats, sc injection ofestradiol or a combination of estradiol and progesterone resulted in a decrease in hypothalamic AVP-mRNA level (P<0.01), but progesterone or testosterone had no effeet. The difference in plasma osmolality between gonadal steriod hormones-treated ratsand vehicle-treated rats was not statistically significant. These findings indicate that gonadal steriod hormones can affect hypothalamic AVP-mRNA level in rats, throughsome central mechanism.