G. Leposavic et al., EFFECTS OF UNILATERAL CASTRATION ON THE HYPOTHALAMIC STRUCTURES INVOLVED IN THE REGULATION OF GONADAL-FUNCTION IN RAT, ARCH I PHYS, 101(1), 1993, pp. 27-33
Citations number
31
Categorie Soggetti
Physiology,Biology,Biophysics
Journal title
Archives internationales de physiologie, de biochimie et de biophysique
This study was undertaken to evaluate the effects of unilateral gonade
ctomy on the hypothalamic structures involved in the regulation of gon
adal function in adult rats of both sexes. Unilateral gonadectomy was
performed; 15 days later stereological parameters of cell activity of
both the halves of hypothalamic preoptico - suprachiamatic area (PO-SC
) and arcuate nucleus (NA) were analyzed. Under the same experimental
conditions the activities of the FSH and LH immunoreactive cells were
analyzed separately in both the halves of the adenohypophysis. The res
ults showed that in the rats of both sexes subjected to unilateral gon
adectomy the mean diameter of cell nuclei of the contralateral half of
PO-SC was significantly greater than that of the ipsilateral half. Ho
wever, in the control intact or bilaterally gonadectomized rats, there
were no significant differences in the values of the same parameter b
etween two halves of PO-SC. On the other hand, neither in the unilater
ally gonadectomized nor in the controls, the values of the mean diamet
er of NA cell nuclei differed significantly between the two halves of
this structure. The FSH and LH pituitary cells behaved like NA cells.
Therefore, since in the experimental animals compensatory function was
developed, and since nervous signaling was different from the sides o
f the removed and intact gland, the present results suggest involvemen
t of a pure nervous mechanism, besides hormonal control, in the regula
tion of the compensatory gonadal function. This mechanism seems to be
functional in the rats of both sexes. These results also indicate that
PO-SC is the anatomical structure involved in this regulation.