Antibodies against phospholipase C inhibit smooth muscle contraction induced by acetylcholine and histamine.
The rationale of this study was to obtain a highly specific inhibitor of phospholipase C by raising rabbit antibodies against the purified bacterial phospholipase C. The antibodies inhibited the enzyme activity in vitro and, as shown by immunofluorescence, cross-reacted with the membrane-bound phospholipase C of isolated guinea-pig smooth muscle cells. Incubation (0-4 h) of guinea-pig taenia coli and ileum with antibodies resulted in a progressive inhibition (up to 85%) of the contractile response evoked by 2 microM acetylcholine or 2 microM histamine but did not inhibit significantly the contraction produced by prostaglandin F2 alpha (0.1 microM). These inhibitory antibodies presumably represent the 'missing tool' needed to establish unequivocally if a given agonist acts via stimulation of the membrane-bound phospholipase C, and implicitly phosphoinositide hydrolysis.
D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D000906:Antibodies / Q000276:immunology*; D015237:Dinoprost; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology*; D007074:Immunoglobulin G / Q000276:immunology; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology*; D011460:Prostaglandins F / Q000494:pharmacology; D011817:Rabbits; D010738:Type C Phospholipases / Q000276:immunology / Q000502:physiology*
D000906:Antibodies; D007074:Immunoglobulin G; D011460:Prostaglandins F; D006632:Histamine; D015237:Dinoprost; D010738:Type C Phospholipases; D000109:Acetylcholine