Neural regulation of the ovary: evidence for hypothalamic asymmetry in endocrine control.

The effects of hypothalamic hemi-islands on ovarian compensatory hypertrophy (OCH) were determined in prepubertal female rats. In animals with hypothalamic hemi-islands on the left side, OCH was blocked in rats hemi-ovariectomized on the ipsi- but not the contralateral side. A potential asymmetrical involvement of the hypothalamus in OCH was suggested by the further observation that this phenomenon could not be demonstrated in rats given hypothalamic hemi-islands on the right side and hemi-ovariectomized on the ipsi- or contralateral side. These data suggest that in addition to a possible direct neural contribution to endocrine feedback, the two-halves of the hypothalamus may differ in terms of their sensitivity to various components of endocrine control.