Adrenomedullin Increases the Short-Circuit Current in the Mouse Seminal Vesicle: Actions on Chloride Secretion

Adrenomedullin (ADM) may regulate seminal vesicle fluid secretion and this may affect sperm quality. In this study, we have investigated the effect of adrenomedullin on chloride secretion in the mouse seminal vesicle. The presence of ADM in mouse seminal vesicle was confirmed using immunostaining and the molecular species was determined using gel filtration chromatography coupled with enzyme-linked assay for ADM. The effects of ADM on chloride secretion were studied by short-circuit current technique in a whole mount preparation of mouse seminal vesicle in an Ussing Chamber. The effects of specific ADM and calcitonin gene-related peptide (CGRP) receptor antagonists were investigated. Whether it depended on the cAMP- and/or calcium-activated chloride channel was also studied using specific chloride channel blockers. The results showed that ADM was present in seminal vesicle epithelial cells. The major molecular species was precursor in the mouse seminal vesicle. ADM increased the short circuit current through the activation of the calcium-activated chloride channel in the mouse seminal vesicle. This stimulatory effect was blocked by the CGRP receptor antagonist, hCGRP8-37. We conclude that ADM may regulate the chloride and fluid secretion from the seminal vesicle, which may affect the composition of the seminal plasma bathing the sperm and hence fertility