Male Reproductive Tract

Oxytocin and Vasopressin Stimulate Anion Secretion by Human and Porcine Vas Deferens Epithelia

Abstract
Experiments were conducted to characterize the effects of oxytocin (OT) and vasopressin (VP) on epithelial cells isolated from human (1°HVD) and porcine (1°PVD) vas deferens and an immortalized epithelial cell line derived from porcine vas deferens (PVD9902 cells). Cultured monolayers were assessed in modified Ussing flux chambers and the OT- or VP-induced change in short circuit current (I_SC) was recorded. All cell types responded to basolateral OT or VP with a transient increase in I_SC that reached a peak of 3-5 µA cm-2. Concentration-response curves constructed with 1°PVD and PVD9902 cells revealed that the apparent K_D (k_app) for OT was ~100 fold less than the k_app for VP. Amplicons for the OT receptor (OXTR) and vasopressin type 2 and type 1a receptors (AVPR2 and AVPR1A) were generated with RT-PCR and the identification of each amplicon confirmed by sequence analysis. A selective antagonist for OXTR and AVPR1A fully blocked the effects of OT and partially blocked the effects of VP when assessed in both 1°PVD and PVD9902 monolayers. APVR2 antagonists blocked the effects of low (30 nM), but not high concentrations of VP, indicating that VP was affecting both AVPR2 and a second receptor subtype, likely OXTR and/or AVPR1A. Experiments employing chelerythrine demonstrated that OT stimulation of vas deferens monolayers requires PKC activity. Alternatively, VP, but not OT, increased the accumulation of cytosolic cAMP in vas deferens epithelial cells. Results from this study demonstrate that OT and VP can modulate ion transport across vas deferens epithelia by independent mechanisms. OT and VP have the potential to acutely change the environment to which sperm are exposed and thus, have the potential to affect male fertility.

Key words: Male Reproductive Tract • Mechanisms of Hormone Action • Oxytocin • Vas deferens • Vasopressin

This article has been cited by other articles:

				F. Pierucci-Alves and B. D. Schultz Bradykinin-Stimulated Cyclooxygenase Activity Stimulates Vas Deferens Epithelial Anion Secretion In Vitro in Swine and Humans Biol Reprod, September 1, 2008; 79(3): 501 - 509. [Abstract] [Full Text] [PDF]