Persistent Vaginal Estrus Research Articles

Gonadotrophic hormone function in persistent estrous rats with hypothalamic lesions.

SummaryElectrolytic lesions in pre-optic and anterior hypothalamic areas of the brain induced persistent (frequent) vaginal estrus and uterine hypertrophy in rats examined 25-300 days post-operatively. Gonad weight eventually decreased. Compensatory hypertrophy of ovary after unilateral castration was inhibited in persistent estrous lesioned rat. FSH stores in adenohypophysis were maintained but titers in serum decreased. The results signify that adenohypophysis of persistent estrous lesioned rat loses its capacity to augment secretion of FSH under conditions of enhanced demand (unilateral oophorectomy).

Persistent estrus produced in rats by hypothalamic lesions.

1) Electrolytic hypothalamic lesions could produce persistent vaginal estrus in rats.2) Ovarian weight of persistent estrus animals was less than the controls; this was attributed to the inhibition and/or lack of corpora lutea formation.3) No marked alteration was observed in adrenals and thyroids.4) Common location of hypothalamic lesions in persistent estrus animals was between Nucl. supraopticus and the rostral part of median eminence; presumably the lesion in Tractus supraopticohypophyseus produces persistent estrus.

The effect of progesterone on persistent vaginal estrus produced by hypothalamic lesions in the rat.

THERE is much evidence indicating that the central nervous system is of importance in the regulation of the hypophysial secretion of gonadotrophic hormones. (Anderson and Haymaker, 1948; Stieve, 1952). Present evidence favors the hypothesis that such control is mediated by neurohumors passing through the hypophysial portal system. (Harris, 1948, Markee, et al., 1952), but the precise nature of such control has not as yet been clearly defined. Although hypothalamic lesions have been employed for many years, systematic studies of pituitaiy function utilizing this technique have been infrequent. With the popularization of the Horsley-Clarke stereotaxic instrument by Ranson and his coworkers it has been possible to produce accurately localized lesions of varying size and thus to permit a more careful study of the problem. Early workers frequently noted the occurrence of genital atrophy and, adiposity following hypothalamic damage (Erdheim, 1904; Bailey and Bremer, 1921) but considerable dispute existed whethe...