Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

The vas deferens forms part of the male reproductive tract and extends from the cauda epididymis to the prostate. Using the patch clamp technique, we have identified a Ca(2+)-activated, voltage-dependent, maxi K+ channel on the apical membrane of epithelial cells cultured from human fetal vas deferens. The channel had a conductance of approximately 250 pS in symmetrical 140 mM K+ solutions, and was highly selective for K+ over Na+. Channel activity was increased by depolarization and by an elevation of bath (cytoplasmic) Ca2+ concentration, and reduced by cytoplasmic Ba2+ (5 mM) but not by cytoplasmic TEA (10 mM). Channel activity was also dependent on the cation bathing the cytoplasmic face of the membrane, being higher in a Na(+)-rich compared to a K(+)-rich solution. We estimated that up to 600 maxi K+ channels were present on the apical membrane of a vas cell, and that their density was 1-2 per mu 2 of membrane. Activity of the channel was low on intact cells, suggesting that it does not contribute to a resting K+ conductance. However, fluid in the lumen of the human vas deferens has a high K+ concentration and we speculate that the maxi K+ channel could play a role in transepithelial K+ secretion.


Journal article


J Membr Biol

Publication Date





69 - 82


Calcium, Cells, Cultured, Epithelium, Female, Fetus, Humans, Male, Patch-Clamp Techniques, Potassium, Potassium Channels, Pregnancy, Vas Deferens