Regulation of tonic gonadotropin release in prepubertal female hamsters

Journal Article · Thu Apr 01 04:00:00 EST 1982 · Endocrinology; (United States)

DOI:https://doi.org/10.1210/endo-110-4-1262· OSTI ID:5464753

Smith, S G; Matt, K S; Prestowitz, W F; Stetson, M H

Basal serum gonadotropin levels were monitored weekly in female hamsters from birth to 10 weeks of age. Hamsters raised on three different photoperiods presented uniform pre- and postpubertal patterns of serum LH and FSH, suggesting that gonadotropin release in the young hamster occurs independently of ambient photoperiod. In all groups, serum LH levels increased gradually in animals up to 4 weeks of age, after which levels plateaued at 50--100 ng/ml. Serum FSH was markedly elevated in 2- and 3-week-old hamsters (800--1200 ng/ml), but remained at 200--400 ng/ml in all other groups. We next examined the change in the responsiveness of the pituitary to exogenous gonadotropin-releasing hormone (GnRH) challenge. Female hamsters 2 days of age failed to respond to any dose (0.025--1000 ng) of GnRH, while 10-day old females responded in typical dose-dependent fashion. GnRH-stimulated LH release first occurred in 6-day-old hamsters and was maximal by day 9, whereas FSH release first occurred on day 8 and was maximal by day 9. The prepubertal pattern of gonadotropin release can, in part, be explained on the basis of the development of pituitary GnRH sensitivity, which occurs independently of photoperiod.

• Research Organization: Physiology Section, School of Life and Health Sciences, University of Delaware, Newark
• OSTI ID: 5464753
• Journal Information: Endocrinology; (United States), Journal Name: Endocrinology; (United States) Vol. 110:4; ISSN ENDOA
• Country of Publication: United States
• Language: English

Related Subjects

551000* -- Physiological Systems
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
BODY
DOSE-RESPONSE RELATIONSHIPS
DYNAMIC FUNCTION STUDIES
ENDOCRINE GLANDS
FEMALES
GLANDS
GONADOTROPINS
HAMSTERS
HORMONES
MAMMALS
ORGANS
PEPTIDE HORMONES
PITUITARY GLAND
PITUITARY HORMONES
REPRODUCTION
RODENTS
VERTEBRATES