title: Effects of heparin on inositol 1,4,5-trisphosphate and guanosine 5'-O-(3-thio triphosphate) induced calcium release in cultured smooth muscle cells from rabbit trachea.
abstract: The effects of heparin on intracellular calcium release in monolayers of permeabilised cultured rabbit smooth muscle cells were determined using 45Ca effluxes. Low molecular weight heparin inhibited inositol 1,4,5-trisphosphate (InsP3) induced Ca2+ release (IC50 = 0.8 microgram/ml), but not guanosine 5'-O-(3-thio triphosphate) (GTP gamma S) stimulated Ca2+ release. Only a small inhibition was noted with high molecular weight heparin and de-N-sulphated heparin, although chondroitin sulphate A potently inhibited the InsP3 response. These results indicate the competitive and specific nature of the heparin effect and give information about the structure of the InsP3 site.
authors.affiliation: Department of Medicine, U.M.D.S., St Thomas' Hospital, London, UK.
authors.forename: L C
authors.initials: LC
authors.lastname: Chopra
authors.forename: C H
authors.initials: CH
authors.lastname: Twort
authors.forename: J P
authors.initials: JP
authors.lastname: Ward
authors.forename: I R
authors.initials: IR
authors.lastname: Cameron
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D006493:Heparin / Q000494:pharmacology*; D066298:In Vitro Techniques; D015544:Inositol 1,4,5-Trisphosphate; D007295:Inositol Phosphates / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D008970:Molecular Weight; D009130:Muscle, Smooth / Q000187:drug effects / Q000378:metabolism*; D011817:Rabbits; D013329:Structure-Activity Relationship; D013403:Sugar Phosphates / Q000494:pharmacology*; D013873:Thionucleotides / Q000494:pharmacology*; D014132:Trachea
chemical_list: D007295:Inositol Phosphates; D013403:Sugar Phosphates; D013873:Thionucleotides; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D015544:Inositol 1,4,5-Trisphosphate; D006160:Guanosine Triphosphate; D006493:Heparin; D002118:Calcium