Experimental cryptorchidism inhibited growth of the rat ventral prostate

Adult Sprague-Dawley male rats, weighing about 350 g, were rendered cryptor chid by suturing the testes to the lateral abdominal wall. Twenty-eight day s later, cryptorchidism resulted in a significant decline in testis weight and suppressed spermatogenesis. The ventral prostate was significantly smal ler in cryptorchid rats. There was no significant difference in serum testo sterone levels between the normal and cryptorchid rats. Charcoal-stripped a queous extracts of the testis from intact and cryptorchid animals were test ed on primary cultures of rat prostatic stromal cells. Cultures treated wit h extract from the intact testis had a significantly increased cell prolife ration as assessed by cell count and by the rate of H-3-thymidine incorpora tion. Additionally, extracts of seminiferous tubules significantly increase d prostate stromal cell proliferation compared to extracts of testicular in terstitial components. Furthermore, this proliferative effect of testicular extracts is specific to the prostate as extract of both normal and cryptor chid testis stimulated proliferation of rat footsole fibroblasts in culture , but only extracts from intact testis stimulated proliferation of prostate stromal cells. These observations demonstrate that the testis produces non androgenic substances that can promote growth of prostatic stromal cells an d that these substances were eliminated in the cryptorchid testis.