Protein synthesis and secretion by the rat seminiferous tubule in vivo not affected by experimental varicocele.

Abstract

Varicocele is associated with testicular dysfunction and male infertility. In vivo protein synthesis and secretion by the seminiferous tubules can be studied as an overall assessment of Sertoli cell function. The present experiments were undertaken to determine the effect of experimental left varicocele (ELV) on seminiferous tubule protein synthesis and secretion. Androgen binding protein (ABP) was determined in native testicular interstitial fluid by radioimmunoassay. 35S-methionine was perifused around seminiferous tubules in vivo in testes of control rats and those with 30 day ELV. Interstitial fluid (IF) and lumen fluid (LF) were subsequently collected by micropuncture, and a tubule extract (TE) was prepared. Proteins in all fluids were subjected to one- and two-dimensional electrophoresis and autoradiography to evaluate the total synthesized proteins (those in TE) as well as the secreted proteins (those in LF). Two-dimensional electrophoresis allowed detection of approximately 170 proteins synthesized by the seminiferous tubules in vivo with 60 of those being secreted into the tubule lumen within a 3-hour time period. Experimental left varicocele significantly reduced the concentration of a specific protein, ABP, in ipsilateral interstitial fluid, but more extensive evaluation of protein synthesis and secretion into the tubule lumen did not corroborate a significant change in protein synthesis and secretion by rat seminiferous tubules under the influence of varicocele. Experimental varicocele does not significantly alter the panel of proteins synthesized by rat seminiferous tubules and secreted into the lumen in vivo. At this level it does not appear that altered Sertoli cell function is within the primary mechanism of dysfunction subsequent to varicocele.