Testosterone upregulates anion secretion across porcine vas deferens epithelia in vitro

Abstract

Testosterone induces and maintains prostaglandin-endoperoxide synthase 2 (PTGS2, also known as cyclooxygenase 2) expression in vas deferens epithelial cells, but it remains unknown whether this has a physiological role in the context of male reproductive biology. Prostaglandins (PG) induce concentration-dependent increases in anion secretion in porcine vas deferens epithelial cell monolayers (1ºPVD), where bicarbonate contributes to cAMP-stimulated anion secretion. Moreover, bradykinin (BK) induces anion secretion across 1ºPVD monolayers that is indomethacin-sensitive, and both PTGS2 and PTGS1 are expressed in this model system. Therefore, it was hypothesized that testosterone modulates anion secretion across vas deferens epithelia via PTGS-dependent pathways and PG synthesis. Porcine vas deferens epithelial cells were isolated and cultured as monolayers on permeable supports until assayed in modified Ussing chambers. RNA and protein were isolated concurrently for semi-quantitative expression analysis. Testosterone upregulated basal and BK-induced short circuit current across 15 1ºPVD monolayers, indicative of anion secretion. Testosterone also induced greater transepithelial electrical resistance. Increases in anion secretion were associated with preferential upregulation of PTGS2 at the mRNA and protein levels. In addition, testosterone induced greater basal and BK-induced anion secretion across vas deferens epithelial cells isolated from the distal segment of the duct. Taken together, these results suggest that testosterone upregulates epithelial responsiveness to acute modulations of anion secretion (likely bicarbonate secretion) that ultimately modifies the environment to which sperm are exposed.