[Biological activity of surfagon--a synthetic luliberin agonist].

The biological activity of surfagon (D-Ala6-desGly10-Pro9-ethylamide), a synthetic LH-RH agonist, is dozens of times higher than that of LH-RH in the test of rat hypophyseal stimulation of gonadotropin secretion in vivo and in vitro and in the ovulation induction test. A dose of surfagon required for the stimulation of LH secretion was considerably lower than that for the stimulation of FSH secretion. It may permit the use of surfagon in clinical practice for selective stimulation of secretion either of LH or total gonadotropins--LH and FSH.