Testicular testosterone concentration, interstitial cell density and spermatogenesis in infertile men

The concentration of testosterone was estimated in testicular biopsies taken from infertile men under general anaesthesia and was found to vary between 0.77 and 9.87 nmol/g wet tissue (median 3.41 nmol/g). Spermatogenesis was assessed by the Johnsen scoring technique but there was no evidence of a deficiency of intratesticular testosterone being associated with dysfunction of the seminiferous tubules. Similarly, there was no direct relationship with testicular size, clinical diagnosis, or the concentration of testosterone found in peripheral plasma taken at the same time as the testicular biopsy. These negative findings were not explained by variation in the volume densities of the Leydig cells assessed in 10 biopsies selected to the representative of the range of testosterone concentrations found in entire series. A retrospective comparison between the concentration of testosterone in peripheral plasma at the time of surgery and the available preoperative levels found in 10 patients provided further evidence for the previously reported lowering of testosterone levels by general anaesthesia. It is suggested that future studies of testicular androgens should be conducted on tissue obtained under local anaesthesia in order to eliminate this effect.