Acute effects of agonists of luteinizing hormone releasing factor (LHRF) on the pituitary, testicular, and ovarian function in monkeys

Abstract

The biological activities of LHRF superactive agonists surfagon (Russia), a promising agent for correcting many disorders of the reproductive function, and busereline (Hoechst A. G., Germany) were assessed by their capacity to stimulate gonadotropin and sex steroids secretion in experiments on adult Papio hamadryas. A single intravenous injection of surfagon and busereline to male monkeys in doses of 50, 500, and 5000 ng/kg similarly stimulated the secretion of luteinizing hormone and testosterone for at least 8 h. Injection of surfagon to females during the early follicular phase induced a prolonged activation of estradiol secretion, more expressed after a dose of 5000 ng/kg. The activating effect of LHRF agonist on follicular steroidogenesis may be associated with subsequent disorders in the pattern and duration of the ovarian menstrual cycle. Injection of surfagon in the middle of the luteal phase had both a luteotropic effect and sharply activated the secretion of estrogens, particularly expressed after a dose of 5000 ng/kg.