title: Guanylin activates rat colonic particulate guanylate cyclase.
abstract: The polypeptide guanylin is an endogenous activator of small intestinal guanylate cyclase. In rat, guanylin mRNA is found predominantly in intestinal tissues, with its highest abundance in the colon. To date, the effect of guanylin on rat colonic particulate guanylate cyclase, however, has not been examined. It was, therefore, of interest to determine whether the addition of guanylin to intact rat colonocytes, or directly to isolated crude colonic membranes, stimulated guanylate cyclase activity. These studies demonstrated that: 1) rat guanylin, in a concentration-dependent manner, rapidly (within min), but transiently, stimulated particulate guanylate cyclase activity when added to intact colonocytes; 2) guanylin also stimulated guanylate cyclase activity when added directly to isolated colonic membranes; and 3) this latter effect of guanylin on guanylate cyclase activity was increased by ATP or ADP and markedly accentuated by ATP gamma S. Taken together, these results demonstrate that guanylin rapidly stimulates rat colonic particulate guanylate cyclase activity and, moreover, that this effect can be modulated by adenine nucleotides.
authors.affiliation: Department of Medicine, University of Chicago, IL 60637.
authors.forename: S
authors.initials: S
authors.lastname: Khare
authors.forename: D
authors.initials: D
authors.lastname: Wilson
authors.forename: R K
authors.initials: RK
authors.lastname: Wali
authors.forename: X Y
authors.initials: XY
authors.lastname: Tien
authors.forename: M
authors.initials: M
authors.lastname: Bissonnette
authors.forename: S M
authors.initials: SM
authors.lastname: Niedziela
authors.forename: M J
authors.initials: MJ
authors.lastname: Bolt
authors.forename: M D
authors.initials: MD
authors.lastname: Sitrin
authors.forename: T A
authors.initials: TA
authors.lastname: Brasitus
mesh_terms: D000255:Adenosine Triphosphate / Q000031:analogs & derivatives; D000704:Analysis of Variance; D000818:Animals; D001427:Bacterial Toxins / Q000494:pharmacology; D002462:Cell Membrane / Q000201:enzymology; D002478:Cells, Cultured; D003106:Colon / Q000201:enzymology*; D004768:Enterotoxins / Q000494:pharmacology; D004789:Enzyme Activation; D029968:Escherichia coli Proteins; D005768:Gastrointestinal Hormones; D006162:Guanylate Cyclase / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D045265:Natriuretic Peptides; D010455:Peptides / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D005768:Gastrointestinal Hormones; D045265:Natriuretic Peptides; D010455:Peptides; C034151:heat stable toxin (E coli); C072685:guanylin; C022571:adenosine 5'-O-(3-thiotriphosphate); D000255:Adenosine Triphosphate; D006162:Guanylate Cyclase