Effect Of Vasectomy On The Testicular Interstitial Tissue Of Japanese White Rabbits:A Morphometric Study

Objective: To study the numerical changes of connective tissue cells in the testicular interstitial tissue of mature rabbits following long-term(6 months) vasectomy.Materials and methods: 12 normal mature male white rabbits were subjected to unilateral vasectomy via the inguinal canal. 6 months post-operation, bilateral testes were removed and methacrylate resin-embedded sections prepared. After the sections were stained with periodic acid-Schiff’s reagent and hematoxylin, histological observation was made and the numbers of connective tissue cells(nuclei) in the interstitial tissue were quantitatively obtained with a stereological method – the optical disector.Results: In all the 12 animals, the total numbers of fibroblasts and cells in the blood vessel wall in the testicular interstitium on the vasectomized side significantly increased, compared to the non-vasectomized side, by 188% and 54%, respectively. And these increases were mainly due to the increases of both cell types in the testes(7 animals) with marked damage to spermatogenesis – the total numbers of the 2 types of cells on the vasectomized side in these 7 animals significantly increased by 320% and 87%, respectively. In addition, in all the 12 animals, the total numbers of other cells(mainly macrophages probably) other than the Leydig cells, myoid cells, fibroblasts and blood vessel cells in the interstitium on the vasectomized side also increased by 100%, but this result was of no statistical significance: the P value of the paired t-test was 0.052.Conclusion: Long-term vasectomy, especially when associated with spermatogenic damage, may lead to increase of the numbers of connective tissue cells in the testicular interstitium.