The endometrium is responsible for the transfer of nutrients, fluid and electrolytes between the circulatory system and the uterine lumen. to a peptide sequence within the regulatory website of CFTR. The effect of PGE2was clogged by basolateral addition of bumetanide and furosemide at concentrations that are Cops5 selective for inhibition of Na+-K+-2Clcotransport activity. The effect of bumetanide onIscwas Cldependent, suggesting a role for the bumetanide-sensitive transport pathway in Clsecretion. PGE2and cAMP also triggered an outwardly rectifying basolateral K+channel which presumably sustains the traveling push for electrogenic Clefflux across the apical membrane. The concentration-conductance and concentration-Iscresponse human relationships for PGE2showed that basolateral K+permeability was rate limiting with respect to transepithelial anion secretion and that activation of a basolateral K+channel by PGE2was necessary to accomplish maximum rates of Clsecretion. The endometrial epithelium consists of a surface epithelium which faces the uterine lumen and a glandular epithelium which invaginates into the endometrial stroma (Davis & Blair, 1993). The endometrium is responsible for the transfer of nutrients, fluid and electrolytes between the circulatory system and the uterine lumen. The transport-related activity of the surface and glandular epithelium provides an ideal intrauterine environment for implantation and embryo development. Previous studies of uterine fluid (-)-Nicotine ditartrate ionic composition from pigs, humans and rats have exposed that the K+concentration is definitely 4- to 5-fold higher than that in plasma, and the Na+concentration is definitely significantly lower than its concentration in plasma (Clemetson, Kim, Mallikarjuneswara & Wilds, 1972;Iritani, Sato & Nishikawa, 1974;Casslen & Nilsson, 1984). Rules of Na+and K+concentrations within uterine and oviduct fluids appears to be important for reproductive events including sperm capacitation, acrosomal reaction, sperm-egg fusion and implantation of the developing embryo (Clemetsonet al.1972;Boldt, Casas, Whaley, Creazzo & Lewis, 1991;Fraser, 1992,1995). Additional important functions of endometrial epithelial cells include rules of luminal pH and uterine fluid volume. Active secretion of Cland HCO3ions offers been shown to establish a driving push for fluid secretion and to regulate luminal fluid pH in the intestine (Wenzl, Sjaastad, Weintraud & Machen, 1989;MacLeod, Redican, Lembessis, Hamilton & (-)-Nicotine ditartrate Field, 1996) and airways (Smith & Welsh, 1992). In rabbit, fluid secretion into the oviduct lumen is definitely driven by active secretion of Clacross the oviduct epithelium (Leese, 1988). Earlier studies using main cultures of human being endometrial epithelial cells cultivated on permeable supports shown that amiloride-sensitive Na+absorption was accompanied by K+secretion across the cell monolayers (Matthews, Thomas, Redfern & Hirst, 1993). Additional studies with main ethnicities of rodent endometrial epithelial cells cultivated on permeable supports showed the short circuit current was stimulated by forskolin, an activator of adenylyl cyclase (Rochwerger, Dho, Parker, Foskett & Buchwald, 1994;Leung, Wong, Gabriel, Yankaskas & Boucher, 1995). In cultured mouse endometrial cells, adrenergic agonists were shown to produce an increase inIscthat was consistent with anion secretion. This response was mediated by -adrenergic receptors and was clogged by apical addition of either glibenclamide or diphenylamine 2,2-dicarboxylic acid (DPC) (Chan, Fong, Chung & Wong, 1997). These experiments indicate that endometrial epithelial cells in tradition are capable of both Na+absorption and anion secretion. Prostaglandins are produced by epithelial (-)-Nicotine ditartrate and stromal endometrial cells in human being and other varieties (Alecozay, Harper, Scheken & Hanahan, 1991;Zhang, Paria & Davis, 1991;Chen, Yang, Hilsenrath, Le & Harper, 1995). They take action in both an endocrine and paracrine manner to increase uterine blood flow, vascular permeability and to regulate menstruation and implantation (Ford, Reynolds & Magness, 1982;Secrets, King & Kennedy, 1986;Chaudhuri, 1991;Yee & Kennedy, 1993). Prostaglandins, specifically PGE2, have been shown to regulate electrolyte transport function in rabbit cortical collecting duct (Sakairi & Jacobson, 1995), prairie puppy gallbladder (Saunders-Kirkwood, Cates & Roslyn, 1993) and porcine distal colon epithelium (Traynor, Brown & O’Grady, 1993). However, little is known concerning the transport-related actions of prostaglandins on endometrial epithelial cells. Recent studies with porcine surface endometrium using amphotericin B-permeabilized cells showed that PGF2improved Na+absorption by activation of.