title: Deletion of microsomal prostaglandin E synthase-1 increases sensitivity to salt loading and angiotensin II infusion.
abstract: Microsomal prostaglandin E synthase-1 (mPGES-1), a membrane-associated protein, is critically involved in the inflammatory response and may be involved in physiological processes as well. The present study examined the role of mPGES-1 in regulation of sodium balance and blood pressure in the settings of salt loading and angiotensin II infusion. mPGES-1 -/- mice developed severe and progressive hypertension associated with an inappropriate increase in sodium balance when fed a high-salt diet. These mice exhibited a significantly impaired ability to excrete an acute enteral load of NaCl. Under these 2 settings of salt loading, urinary excretion of prostaglandin E(2) and nitrate/nitrite were remarkably increased in wild-type animals but not in mPGES-1 -/- mice. The changes of urinary cGMP paralleled that of urinary nitrate/nitrite. mPGES-1 -/- mice exhibited a remarkable inhibition of high salt-induced increase in gene expression of all 3 NO synthase isoforms, whereas these mice had upregulated expression of NO synthase III but not NO synthase I and NO synthase II at basal state. Chronic salt loading remarkably induced mPGES-1 protein expression exclusively in the distal nephron. In primary cultures of CD cells, mPGES-1 expression was significantly increased following exposure to hypertonic NaCl, in parallel with increased prostaglandin E(2) release. These findings have revealed a mPGES-1/prostaglandin E(2)/NO/cGMP pathway that appears to be critically important for salt adaptation. In addition, we provide evidence that mPGES-1 deficiency sensitized the hypertensive effect of angiotensin II. Overall, this study has characterized the natriuretic and antihypertensive role of mPGES-1 that likely contributes to blood pressure homeostasis.
authors.affiliation: Department of Internal Medicine, University of Utah and Veterans Affairs Medical Center, Salt Lake City, UT 84132, USA.
authors.forename: Zhanjun
authors.initials: Z
authors.lastname: Jia
authors.forename: Aihua
authors.initials: A
authors.lastname: Zhang
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.forename: Zheng
authors.initials: Z
authors.lastname: Dong
authors.forename: Tianxin
authors.initials: T
authors.lastname: Yang
mesh_terms: D000804:Angiotensin II / Q000008:administration & dosage* / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D015870:Gene Expression / Q000187:drug effects; D007260:Infusion Pumps; D019746:Intramolecular Oxidoreductases / Q000172:deficiency* / Q000235:genetics; D007679:Kidney Medulla / Q000033:anatomy & histology / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009569:Nitric Oxide / Q000096:biosynthesis; D010641:Phenotype; D000071876:Prostaglandin-E Synthases; D012964:Sodium / Q000378:metabolism*; D017673:Sodium Chloride, Dietary / Q000494:pharmacology*
chemical_list: D017673:Sodium Chloride, Dietary; D000804:Angiotensin II; D009569:Nitric Oxide; D012964:Sodium; D019746:Intramolecular Oxidoreductases; D000071876:Prostaglandin-E Synthases; C000605865:Ptges protein, mouse