[Effect of the administration of hypothalamic nonapeptides and their fragments on the hypothalamo-hypophyse-ovarian system in hens].

Single injection of hypothalamic nonapeptidae do not affect ovulation although they inhibit endocrine and reproductive functions of the hypothalamo-hypophyseal-ovarial system in hens. Repetitive injections of nonapeptides, on the contrary, enhance reproductive processes. This effect is due to the structure of the cyclic part of neurohormonal molecule.