Leydig cell function was studied in 108 varicocele (V) patients with a mean age of 30.9 years, and a control group (C) of 46 men with a mean age of 30 years. Plasma gonadotropin levels were determined before and after GNRH stimulation. Testosterone (T), 17-OH-progesterone (17-OH-P), dihydrotestosterone (DHT) and estradiol (E2) were also assayed. Mean plasma T levels were significantly decreased in varicocele patients (V = 416 +/- 12.9, n = 106; C = 487 +/- 19.9, n = 40; P less than 0.01), while the basal 17-OH-P/T ratio was significantly increased (V = 0.38 +/- 0.02, n = 56; C = 0.28 +/- 0.02, n = 40; 0.02 greater than P greater than 0.01) and remained higher after hCG stimulation (P less than 0.01). No significant differences in mean sex steroid levels were observed when comparing varicocele patients with normal sperm counts (VN) and those who had oligozoospermia (VO). There was a significant negative linear correlation between age and 17-OH-P (n = 56; r = -0.47; P less than 0.01) and T values (n = 106; r = 0.27; P less than 0.01) in varicocele patients, which contrasted with the absence of any significant correlation with age in the controls. These data suggest that the duration of idiopathic varicocele influences testicular hormone secretion.

Abstract. In order to study Leydig cell function in patients with varicoceles, we determined plasma levels of the most important testicular steroids, 17-OH-progesterone (17-OH-P) and testosterone (T) in the basal condition and after hCG stimulation. There was a significant inverse linear correlation between age, plasma testosterone, and 17-OH-P (n = 65, r = 0.316, P = 0.01, n = 48, r = 0.532, P = 0.01). This was in contrast to the absence of such correlations in normal men in the same age range. Following hCG stimulation in 16 patients the 17-OH-P/T ratio was significantly increased with respect to normal controls. No correlation was been observed between sperm count and age in varicocele patients. Analysis of variance of 17-OH-P plasma levels between the patients with a sperm count less than 10 million/ml and that of more than 10 million/ml did not reveal any significant difference. These results suggest that the deleterious effects of varicocele on seminiferous tubules and Leydig cells are unrelated. Moreover the increased 17-OH-P/T ratio after hCG stimulation suggests that some enzymatic impairment involving the last steps of testosterone biosynthesis exists in patients with varicoceles. This is evident in middle aged varicocele patients with a premature decrease of plasma levels of testosterone.

In the present study we determined progesterone (p), 17-OH-progesterone (17-OH-P), androstenedione (\g=D\4), dehydroepiandrosterone (DHEA) and testosterone (T) in spermatic venous blood of 34 varicocele patients and of 13 normal subjects. We also used the DHEA/\g=D\4 ratio as an index of the \ g=D\ 5/ \ g=D\ 4 pathway ratio in testosterone biosynthesis.

In the present study, we have evaluated the influence of the location of the blood sampling in the spermatic vein on the steroid concentrations observed. Simultaneous blood sampling at two different points of the spermatic vein (iliac level and pampiniform plexus) was perfomed in the same patients during a surgical protocol for varicocelectomy. In order to further evaluate which of the two sampling points is more useful to investigate testicular secretion, we have performed both forms of sampling in 4 volunteers given an HCG stimulation 24 h before the surgical procedure. It was found that levels of testosterone (T) and 17α-hydroxyprogesterone (17-OHP) were higher in the pampiniform plexus (scrotal) than at the iliac sampling point (T scrotal 1,168.343 ± 142.65 nmol/l, iliac 850.63 ± 143.411 nmol/l, n = 21, p < 0.01; 17-OHP scrotal 260.130 ± 43.14 nmol/l, iliac 164.46 ± 31.02 nmol/l, n = 17, p < 0.01). This indicates that spermatic blood collected at the scrotal sampling point has received more blood coming from the testis than the blood collected at the iliac point. We did not observe significant differences in progesterone and Δ4-androstene-dione (Δ4) levels between the two samplings. The T/Δ4 ratio was significantly lower in the iliac than in the scrotal sampling (T/Δ4 scrotal 31.420 ± 6.69; iliac 15.41 ± 3.84; p < 0.05). After HCG stimulation, testosterone concentrations were higher in the pampiniform plexus than in the iliac sample. This suggests that the first sampling point is more proper for studying testicular secretion. Both T/Δ4 and T/17-OHP ratios were significantly higher at the iliac sampling (median T/Δ4 scrotal 33.909, iliac 17.64, 0.03 > p > 0.02; median T/17-OHP scrotal 4.86, iliac 3.06, p < 0.05). These results show that the ratio between testosterone and its precursors is also influenced by the point of blood collection in the spermatic vein.