ALTERATIONS OF TESTICULAR FUNCTION AFTER INDUCED AUTOIMMUNE ORCHITIS IN RATS

The endocrinological profile of animals with experimental autoimmune o rchitis (EAO) has not been sufficiently explored. With this purpose or chitis was induced in adult rats by active immunization with testicula r homogenate (TH) and adjuvants. Animals were sacrificed 50 or 80 days after the first immunization. Forty-three percent of rats immunized w ith TH developed orchitis. Different degrees of cell sloughing and atr ophy of the seminiferous tubules and numerous macrophages and lymphocy tes in close association with Leydig cells were seen. A significant in crease in the number of Leydig cells was observed in rats with orchiti s killed at 50 and 80 days. An enhanced number of interstitial non-Ley dig cells was also detected in rats with testicular damage killed at 8 0 days. Levels of serum follicle-stimulating hormone (FSH) were two- t o threefold higher in rats with EAO compared to concentrations detecte d in other groups. Moreover, rats with orchitis had significantly incr eased testicular testosterone. Serum luteinizing hormone (LH) did not change in animals of any group. In vitro studies showed an increase in the basal and human chorionic gonadotropin (hCG)-stimulated testoster one production in rats with EAO. The increase in testicular steroidoge nesis without a concomitant enhancement in serum LH levels detected in rats with autoimmune orchitis suggests the existence of local control mechanisms.