Plasma Progestins, Estradiol, and Luteinizing Hormone Following Prostaglandin F2α Injection
Year: 1976
Type: article
Abstract: Dairy animals, ranging from days 8 to 13 of the estrous cycle, were fitted with indwelling jugular catheters 1 day prior to either intramuscular injection of prostaglandin F2a free acid (30 mg, n = 4) or intrauterine, deposition of prostaglandin F2a free acid (10 mg, n = 3).Blood samples were collected at 6, 4, 2, and 0 h prior to administration of prostaglandin F2~ and at 1, 3, and every 2 h thereafter until ovulation.Progestins, estradiol, and luteinizing hormone in plasma were measured by radioimmunoassay.Hormonal changes and interrelationships within animals were evaluated by least squares analyses.Decreases in progestins of plasma within 24 h indicated prostaglandin F2a induced luteolysis in six of the seven animals.Estradiol increased linearly from time of injection to 52 h postinjection.Intervals from administration of prostaglandin to onset of estrus, peak of luteinizing hormone, and ovulation were 74.9 -+ 21, 78.8 + 21, and 99.5 -+ 19 h. INTRODUCTI ONIn recent years there has been considerable interest in establishing an ovulation-control system which allows for a predetermined time of insemination.Such a system would minimize estrous detection and allow for a more precise timing of insemination to maximize conception rates.Administration of prostaglandin F2~ (PGF2a) induces regression of corpora lutea in cattle, which is followed by an increase in
Source: Journal of Dairy Science
Institutions: National Institutes of Health, University of Florida
Language: English
Subfield: Agronomy and Crop Science
Domain: Life Sciences
Open Access status: bronze
Funder: National Institutes of Health
OpenAlex ID: W2046740392