PARTITION OF ANDROGEN BETWEEN THE LYMPH AND VENOUS BLOOD OF THE TESTIS IN THE RAM

Abstract

SUMMARY Testicular lymph collected from rams contained testosterone and androstenedione. The concentration of testosterone in testicular lymph ranged from < 2·5 to 10·6 μg./100 ml. in untreated rams, and from 8·9 to 61·4 μg./100 ml. in rams treated with human chorionic gonadotrophin, and was closely correlated with the hormone level in testicular venous blood. Testosterone concentration in lymph was lower than that in the plasma of spermatic vein blood (mean ratio 0·61), but was two to eight times higher than the concentration in arterial blood plasma. Blood flow rate through the testis (2–3 l./hr.) was 300 to 400 times higher than the mean rate of lymph collection (7·5 ml./hr./testis). It is concluded that only a very small fraction of the androgen output of the testis is carried to the general circulation in lymph. It appears, however, that androgen release is attended by escape of testosterone into the tissue fluid of the testis, and hence the seminiferous tubules may be exposed to much higher concentrations of the hormone than are androgen target organs remote from the testis.