Contractile properties of synthetic cationic polypeptides in guinea-pig isolated trachea.
1. The synthetic polypeptides, poly-L-arginine, poly-L-lysine and poly-D-lysine contract guinea-pig isolated trachea in a concentration-dependent, epithelium-independent manner. Indomethacin augmented the contractile response to poly-L-arginine. 2. The contractile response to poly-L-arginine was not significantly inhibited by nicardipine, a selective L-type calcium channel blocker or by the histamine H1-receptor antagonist, mepyramine nor significantly augmented by the neutral endopeptidase inhibitor, phosphoramidon. 3. The contractile response to poly-L-arginine was inhibited in a concentration-dependent manner by prior incubation of guinea-pig tracheal rings with a number of anionic polypeptides including, low molecular weight heparin, poly-L-aspartic acid and bovine serum albumin. 4. In vitro capsaicin-induced desensitization failed to attenuate the contractile response to poly-L-arginine, suggesting little, if any role for sensory neuropeptides in the functional response in the guinea-pig. 5. Synthetic polypeptides induce an epithelium-independent, charge-dependent contraction of guinea-pig isolated trachea.
Department of Pharmacology, University of Western Australia, Nedlands.
D
D
Spina
R G
RG
Goldie
D000818:Animals; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D006020:Glycopeptides / Q000494:pharmacology; D006168:Guinea Pigs; D006493:Heparin / Q000494:pharmacology; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D015260:Neprilysin / Q000037:antagonists & inhibitors; D009529:Nicardipine / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology*; D011107:Polylysine / Q000494:pharmacology*; D011738:Pyrilamine / Q000494:pharmacology; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D014132:Trachea / Q000187:drug effects* / Q000502:physiology
D006020:Glycopeptides; D010455:Peptides; D011107:Polylysine; C015462:polyarginine; C017645:polyaspartate; D012710:Serum Albumin, Bovine; D006493:Heparin; D009529:Nicardipine; D015260:Neprilysin; D011738:Pyrilamine; C008890:phosphoramidon