Reflex factors that modify the reserpine effect on the ovulation

Abstract

An experimental study in rats has been realized with the purpose of obtaining data on reflex factors in the ovulation. Several groups of rats have been set in different conditions of copulation in the phases of metaestro, diestro and proestro.

The inhibition of the ovulation, observed in previous experiments by adminis­ traron of reserpine (2 mg/kg) at the eight hour of the day of diestro, neutralized by the copulation, as it has been shown by the fact that rats treated with reserpine at the same dosis and in the same step of the cycle were fecundated. The ovulation is attributed to genital reflex mechanisms. The inhibition of the ovulation observed in rats treated with 4 mg/kg of reserpine at the eight hour of the day of proestro, was compared to the inhibition of the fecundation found when reserpine was administered in identical conditions. This suggests that a certain level of catecholamines is necessary for the onset of the ovulation.

In rats set in conditions of coupling in the phase of metaestro during 24 and 48 hours, fecundation was not observed neither in the Controls níƒor in the rats subjected to previous vaginal stimulation. In all cases, both with and without copulation, a length- ening of the phase of diestro was found. The ovarles showed a pronounced diffuse luteinization. The same results and morphological changes were attained in rats set in conditions of coupling in the phase of diestro during 16 hours. The histological study showed a great similarity in the morphological changes of the ovarían tissue, observed in the rats treated with reserpine 4 mg/kg at the eight hour of the day of proestro in which the ovulation did not take place. The diffuse luteinization of Uíˆie ovary found in both cases is interpreted as due to a greater secretion of prolactine, by vaginal or extravaginal reflex mechanisms in some cases, and by reserpine in others.

In a different group of rats set in conditions of copulation in the phase of diestro during 16 hours, to which amphetamine 4 mg/kg was previous by given fecundation was not observed, níƒor any significant change in the length of the phases of the cycle. The histological study of the ovaries showed the morphology corresponding to the phases in which the rats were killed. From these data, the role of adrenergic mechanisms related to spontaneous ovulation and to reflex ovulations is emphasized.