The androgen status of vasectomized rats

Several factors related to androgen status were examined in vasectomized and sham-operated rats during and at the end of the 7th postoperative month. Average serum testosterone levels during the 7th month were based on three biweekly bleedings of 12 rats in each group, with determined values of 1.84 plus or minus 0.61 ng/ml (X plus or minus SD) for vasectomized rats and 2.38 plus or minus 0.78 ng/ml for sham-operated rats. Although average serum testosterone levels were 23% lower in vasectomized rats as compared to sham-operated controls, high coefficients of variation (33% and 32% in the two groups, respectively) rendered the difference insignificant. Within 1 hr of hCG administration, serum testosterone rose to 5.07 plus 1.94 ng/ml and 5.73 plus or minus 3.21 ng/ml in vasectomized and sham-operated rats. Eighteen hr after castration, testosterone had fallen below 0.25 ng/ml in both groups. Weights of testes and accessory sex organs were similar in both groups. Significant differences were not detected in the abundance, volume, or ultrastructure of Leydig cells. Each category of data collected in this study failed to reveal statistically significant differences were not detected in the abundance, volume, or ultrastructure of Leydig cells. Each category of data collected in this study failed to reveal statistically significant differences between the two groups, thereby supporting the essential normalcy of vasectomized rats with respect to androgen status.