Persistent estrus in rats after anterolateral hypothalamic microinjections of 6-hydroxydopamine.

Bilateral injections of 30 mug of 6-hydroxydopamine (6-OHDA, as base) into the anterolateral hypothalamic area induced constant vaginal cornification (CVC), polyfollicular ovaries and uterine hypertrophy in cyclic adult female rats. There were no important changes in the vaginal patterns or ovarian and uterine morphology in animals given injections in the same area with the solvent only and in animals given injections with 6-OHDA in the anterior amygdaloid area. It is suggested that the persistent estrus after anterolateral hypothalamic injections of 6-OHDA results from lesions of central catecholaminergic pathways, which are probably involved in gonadotropin secretion.