title: Intracellular signals in IgG-mediated anaphylactic contraction of single smooth muscle cells.
abstract: Single smooth muscle cells from the taenia coli of guinea pigs passively sensitized with anti-egg albumin IgG fraction were used to evaluate the intracellular signal transduction system during anaphylactic contraction. 125I-IgG was bound to single smooth muscle cells, and sensitized smooth muscle cells contracted in response to antigen treatment. In response to neuraminidase treatment, 125I-IgG binding to the cells was decreased, along with an inhibition of anaphylactic contraction. Pretreatment with islet-activating protein (IAP), neomycin, quercetin and H-7 inhibited anaphylactic contraction, whereas pretreatment with phorbol 12,13-dibutylate augmented the contraction. The signal produced by the interaction between IgG bound to the smooth muscle cells and antigen appears to be transmitted to the intracellular contractile element via the signal transduction system involving G protein. Phospholipase-C and -A2 appear to be the effectors in the signal transduction system for anaphylactic contractions. Protein kinase C, activated with reference to phospholipase-C, also may be involved in anaphylactic contraction.
authors.affiliation: Department of Pharmacology, Nippon Medical School.
authors.forename: K
authors.initials: K
authors.lastname: Nemoto
authors.forename: T
authors.initials: T
authors.lastname: Okamura
mesh_terms: D000707:Anaphylaxis / Q000276:immunology* / Q000503:physiopathology; D000818:Animals; D003106:Colon; D005260:Female; D019204:GTP-Binding Proteins / Q000502:physiology; D006168:Guinea Pigs; D007074:Immunoglobulin G / Q000502:physiology*; D066298:In Vitro Techniques; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000378:metabolism / Q000503:physiopathology*; D015398:Signal Transduction
chemical_list: D007074:Immunoglobulin G; D019204:GTP-Binding Proteins