Testosterone reaction after testicular biopsies--further investigation in the normogonad and cryptorchid rat model.

From the follow-up of patients undergoing extensive testicular sperm extraction, the question of a consecutive decrease in testosterone levels arose. Further investigation was performed in the normogonad and cryptorchid Sprague-Dawley rat model. From groups A (n = 40 normogonad rats) and B (n = 40 cryptorchid rats), eight animals were taken and the following surgical interventions were performed: general anaesthesia (A-0, B-0), scrotal exploration (A-1, B-1), one testicular biopsy with a 2-mm tunica incision (A-2, B-2), two biopsies with a 4-mm incision (A-3, B-3), and four biopsies with a 2-mm incision (A-4, B-4). Standardised testosterone control was performed 1 day before as well as 1, 7 and 14 days after surgery. No specific testosterone reaction was found in A-0, an insignificant decrease in A-1 (3.8 nmol/l), a significant decrease in A-2 (6.27 nmol/l), in A-3 (12.96 nmol/l) and in A-4 (11.88 nmol/l). In the B rats, even in B-3 and B-4 no significant decrease was measured. The testosterone reaction correlated to the amount of tissue that was extracted, but not to the number of biopsies. The cryptorchid rats did not react in a more sensitive manner.