The effect of hypophysectomy on proluminal movement of 3H-androgens across the epididymal epithelium in the rat.

The effect of hypophysectomy on transepithelial movement of 3H-androgen in the rat epididymis was examined by using in vivo microperifusion of 3H-testosterone followed by in vivo micropuncture to obtain peritubular and intraluminal fluids. Experiments were performed on animals without hypophysectomy or on animals 5-6 days after hypophysectomy and 9-10 days after hypophysectomy. Tubules were perifused with Minimum Essential Medium containing 3H-testosterone. 14C-polyethyleneglycol was included in the perifusion fluid as a marker for contamination of the intraluminal fluid by peritubular fluid. Radioactivity of isotopes in the interstitial and intraluminal fluid was determined at 1 and 2 hours after perifusion and the percentage of peritubular isotopes appearing in the intraluminal fluid was determined. A sperm concentration microassay was performed on micropuncture samples from the epididymal tubules to assess testicular contribution to the lumen content. Proluminal movement of 3H-androgen and intratubular sperm concentrations in the caput epididymal tubules of rats 9-10 days after hypophysectomy were significantly decreased. Proluminal movement of 3H-androgen and intratubular sperm concentrations in the cauda epididymal tubules of rats 9-10 days after hypophysectomy were significantly increased. These results suggest that proluminal androgen movement is controlled by the presence of some testicular product in the epididymal lumen.