Gonadorelin-induced testosterone release: a biological assay for quality assurance of gonadorelin in veterinary medicine.

Abstract

Two experiments were conducted with bulls administered norgestomet and gonadorelin to determine if the gonadorelin-induced release of testosterone could be developed into a biological assay for quality assurance of gonadorelin. Implants containing norgestomet (0 to 36 mg) reduced the episodic release (r = -.81; P < .05) and mean concentrations of testosterone (r = -.82; P < .05). Gonadoreline-induced testosterone release increased (r = .99; P < .05) with increasing dosage of gonadorelin (up to 5 micrograms) in norgestomet-implanted bulls (36 mg). Maximal testosterone was released (> sixfold increase) with 5 to 40 micrograms of gonadorelin. In summary, the gonadorelin-induced testosterone release in bulls administered a synthetic progestin is a sensitive (0.008 microgram per kg body weight for 5 micrograms of gonadorelin) biological assay with a rapid turnaround time for the confirmation of gonadorelin potency. Based on a per-kg-body-weight basis, the norgestomet-treated bull is the most sensitive biological assay model.

• Authors: D J Kesler, R N Summers, C A Peterson, T L Steckler
• Journal: Drug development and industrial pharmacy (Drug Dev Ind Pharm) Vol. 25 Issue 3 Pg. 315-21 (Mar 1999) ISSN: 0363-9045 [Print] England
• PMID: 10071824 (Publication Type: Journal Article)

Chemical References

• Drug Implants
• Pregnenediones
• Progestins
• Gonadotropin-Releasing Hormone
• norgestomet
• Testosterone

Topics

• Animals
• Biological Assay (veterinary)
• Cattle
• Drug Implants
• Gonadotropin-Releasing Hormone (pharmacology, standards)
• Male
• Pregnenediones (pharmacology)
• Progestins (pharmacology)
• Quality Control
• Testosterone (metabolism)
• Time Factors