title: Inhibition of renal alkaline phosphatase by cimetidine.
abstract: Alkaline phosphatase (ALP) belongs to hydrolase group of enzymes. It is responsible for removing phosphate groups from many types of molecules, including nucleotides and proteins. Cimetidine (trade name Tagamet) is an antagonist of histamine H2-receptor that inhibits the production of gastric acid. Cimetidine is used for the treatment of gastrointestinal diseases. In this study the inhibitory effect of cimetidine on mouse renal ALP activity was investigated. Our results showed that cimetidine can inhibit ALP by uncompetitive inhibition. In the absence of inhibitor the V(max) and K(m) of the enzyme were found to be 13.7 mmol/mg prot.min and 0.25 mM, respectively. Both the Vmax and Km of the enzyme decreased with increasing cimetidine concentrations (0- 1.2 mM). The Ki and IC(50) of cimetidine were determined to be about 0.5 mM and 0.52 mM, respectively.
authors.affiliation: BioResearch Lab, Faculty of Biological Sciences, Shahid Beheshti University G.C, Iran. D_MTehrani@sbu.ac.ir
authors.forename: Dariush
authors.initials: D
authors.lastname: Minai-Tehrani
authors.forename: Somayeh
authors.initials: S
authors.lastname: Khodai
authors.forename: Somayeh
authors.initials: S
authors.lastname: Aminnaseri
authors.forename: Saeed
authors.initials: S
authors.lastname: Minoui
authors.forename: Zahra
authors.initials: Z
authors.lastname: Sobhani-Damavadifar
authors.forename: Sana
authors.initials: S
authors.lastname: Alavi
authors.forename: Raheleh
authors.initials: R
authors.lastname: Osmani
authors.forename: Shiva
authors.initials: S
authors.lastname: Ahmadi
mesh_terms: D000469:Alkaline Phosphatase / Q000037:antagonists & inhibitors*; D000818:Animals; D002927:Cimetidine / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006635:Histamine H2 Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D020128:Inhibitory Concentration 50; D007668:Kidney / Q000201:enzymology / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C
chemical_list: D006635:Histamine H2 Antagonists; D002927:Cimetidine; D000469:Alkaline Phosphatase