REgulation of ion transport across porcine glandular enoometrium

Previous studies have shown that surface endometrial cells absorb Na and secrete K ions and that these processes are regulated by prostaglandins. The objective of this study was to investigate the regulation of ion transport within glandular endometrium. Glandular epithelial cells, isolated from porcine uterus, were cultured on permeable supports. The filters (4.5 cm2) with high resistance were mounted on Ussing chambers and bathed on both sides with porcine Ringer solution. The mean tissue conductance was 1.00 ±0.07 mS/cm and the mean basal Isc was 3.33 ±0.25 nA/cnf. Luminal addition of benzamil, a Na channel blocker, at a concentration of 10 nM inhibited the basal Isc by 61.12 ±10.28 %. Luminal addition of NPPB, a CI channel blocker, at a concentration of 200 nM inhibited the basal Isc by 66.38 ±4.98 %. These results indicate that the basal Isc is dependent on benzamil-sensitive Na channels and on NPPB-sensitive CI channels. Addition of 3 (iM PGEZ to basolateral solution increased Isc by 3.70 ±0.59 \iMcnf. Pretreatment of monolayers with benzamil had no significant effect on the increase in Isc produced by PGE;. However, pretreatment with NPPB blocked the PGE;- mediated increase in Isc, suggesting that the PGE2 response is dependent on the activity of apical NPPB-sensitive CI channels.