Razi Journal of Medical Sciences

Present experiments was undertaken to study the possibility of vagus nerve function on the control of testosterone secretion.

For this reason the effect of right or left side vagotomy on serum testosterone concentration was studied in rats with two testes in situ and in hemicastrates. 80 male rats with 250 - 270 gr weight allocated to 8 groups. In all groups except sham vagus nerve were cut bellow the diaphragm and castration were done immediately after ·vagotomy. Testosterone concentration decreased significantly in bHateralyvagotomized, rightvagtomized and right vagotomized rats with right testes in situ. Also compensatory testicular hypertrophy was observed in right vagotomized rats and in rats which vagotomy on right was accompanied by right castration. The results of these experiments support the hypothesis that the vagus nerve may playa modulatory role in the control of gonadal function.