Effects of the daily administration of gonadotrophin-releasing hormone on the anterior pituitary gland of rats with restricted feeding.
To investigate the influence of weight reduction on pituitary function and its modulation by gonadotrophin-releasing hormone (GnRH), female rats were restricted to 10 g food/day for 60 days. GnRH (5 micrograms) or saline (0.2 ml) were administered daily between days 31 and 60 of the period of underfeeding. Underfeeding brought about a decrease in the pituitary gonadotrophin content, serum levels of gonadotrophins and oestradiol, and the number and size of both LH- and FSH-positive pituitary cells. The administration of GnRH to underfed rats produced an increase in the pituitary and serum gonadotrophin levels and the number and size of both LH- and FSH-positive pituitary cells. These observations suggest that underfeeding and/or weight loss diminish the number and activity of the pituitary gonadotrophs, and that daily administration of GnRH both increases the number of gonadotrophs and augments their activity.
Kotsuji
F
F
Department of Obstetrics and Gynecology, Fukui Medical School, Japan.
Hosokawa
K
K
Tominaga
T
T
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002452:Cell Count; D004038:Diet, Reducing; D004958:Estradiol / Q000097:blood; D004971:Estrus / Q000187:drug effects; D005260:Female; D005640:Follicle Stimulating Hormone / Q000032:analysis; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D007150:Immunohistochemistry; D007986:Luteinizing Hormone / Q000032:analysis; D009929:Organ Size / Q000187:drug effects; D010053:Ovary / Q000033:anatomy & histology; D010902:Pituitary Gland / Q000737:chemistry; D010903:Pituitary Gland, Anterior / Q000033:anatomy & histology / Q000166:cytology / Q000187:drug effects*; D011863:Radioimmunoassay; D051381:Rats; D017208:Rats, Wistar
D007987:Gonadotropin-Releasing Hormone; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone