[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 3'-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 males was 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 rats was 30% higher than that in sham-operated intact females (P < 0.05). Although the hypothalamic AVP mRNA level tended to be lower in castrated males than in sham-operated intact males, the difference was not statistically significant. The difference in plasma 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 of estradiol and progesterone were without effect. In ovariectomized rats, sc injection of estradiol 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 effect. The difference in plasma osmolality between gonadal steriod hormones-treated rats and vehicle-treated rats was not statistically significant. These findings indicate that gonadal steriod hormones can affect hypothalamic AVP-mRNA level in rats, through some central mechanism.
Dai
W J
WJ
Department of Physiology, Shanghai Medical University.
Lu
L M
LM
Yao
T
T
D000818:Animals; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D007031:Hypothalamus / Q000378:metabolism*; D008297:Male; D009919:Orchiectomy; D010052:Ovariectomy; D011374:Progesterone / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013739:Testosterone / Q000494:pharmacology; D014667:Vasopressins / Q000378:metabolism*
D012333:RNA, Messenger; D014667:Vasopressins; D013739:Testosterone; D011374:Progesterone; D004958:Estradiol