TESTICULAR DENERVATION-INDUCED NUCLEAR-CHANGES IN LEYDIG-CELL OF HEMICASTRATED ADULT RATS

In the adult male rat, hemicastration (HC) induces a remarkable enhanc ement of testosterone secretion from the Leydig cells of the remaining testis. We have observed previously that the denervation of inferior spermatic nerves inhibits this enhancement. The present experiments we re designed to assess morphometrically whether or not this change had a cytological correlate in Leydig cells. At least five testes from eac h group (denervation plus HC, sham denervation plus HC and intact rats ) were prepared for both optical and electron microscopy studies. The results showed that after 24 h of denervation, the nuclear volume of t he Leydig cells in denervation plus HC rats was smaller (p < 0.01) tha n those of sham denervation plus HC (196.56 +/- 16.53 vs. 280.71 +/- 1 3.37), whereas both the volume density of heterochromatin (19.84 +/- 3 .14 vs. 10.03 +/- 2.47%) and the heterochromatin index (expressed as p eriphery heterochromatin area divided by nuclear perimeter, 0.149 +/- 0.046 vs. 0.094 +/- 0.026) were significantly (p < 0.01) higher in den ervation plus HC rats than in its sham groups. No changes in Leydig ce ll numbers or cytoplasmic organelles were detected. The results sugges t that some nuclear and heterochromatin-associated cellular activity m ight be inhibited by testicular denervation in hemicastrated rats.