Spermatic and peripheral plasma concentrations of testosterone and androstenedione in prepubertal boys

Spermatic and peripheral plasma concentrations of testosterone (T) and androstenedione (A) have been measured in prepubertal boys affected by inguinal hernia (group I; n = 7) and unilateral undescended testis (group II; n = 18). Mean (+/- SE) spermatic T concentrations (47.7 +/- 14.8 ng/dl in group I; 36.3 +/- 3.4 ng/dl in group II) were significantly different from mean peripheral T concentrations (9.8 +/- 2.1 ng/dl in group I; 9.3 +/- 0.9 ng/dl in group II) in both groups (P less than 0.05 and P less than 0.0005, respectively). Mean spermatic A concentration (59.7 +/- 4.9 ng/dl) was significantly higher than mean peripheral A concentration (49.8 +/- 4.9 ng/dl) in group II (P less than 0.05) but not in group I. Mean spermatic and peripheral T and A values found in boys of group I were not significantly different from those found in group II. The mean spermatic/peripheral T ratio was higher (5.01 in group I; 4.42 in group II) than the corresponding mean spermatic/peripheral A ratio (1.27 in group I; 1.32 in group II) in both groups. Our data suggest that 1) although testicular T secretion is present in all prepubertal boys, A secretion is not constant and often negligible; 2) the contribution of testicular secretion to the circulating T is much more important than the contribution to the circulating A; 3) no significant differences were found between the testicular secretory pattern of prepubertal boys with inguinal hernia and unselected boys with unilateral undescended testis.