The enzyme is released from the plasma membrane during capacitation. Incubation with angiotensin II induces the human sperm acrosome reaction. The ability of testicular macrophages and T cells to elicit an immune response is strongly suppressed. This phenomenon is regulated locally and probably under strong influence of Leydig cell products. The cytokine MIF is synthesized by the Leydig cells and plays a role as a local mediator in rat testis.
Current studies show a slightly higher pregnancy rate for epididymal spermatozoa.
But these results are influenced by female factors, so that a standardised animal model is necessary to clear this question. For this, microsurgical epididymal and testicular spermatozoa will be retrieved after vasectomy in a rabbit model. These spermatozoa will be examined by histological and molecular methods for chromatin condensation, acrosomal enzyme, CREM, TP1 and protamine concentration. The aim of this study is to compare these parameters before and after vasectomy.