D. Spina et Rg. Goldie, CONTRACTILE PROPERTIES OF SYNTHETIC CATIONIC POLYPEPTIDES IN GUINEA-PIG ISOLATED TRACHEA, British Journal of Pharmacology, 111(1), 1994, pp. 29-34
1 The synthetic polypeptides, poly-L-arginine, poly-L-lysine and poly-
D-lysine contract guinea-pig isolated trachea in a concentration-depen
dent, epithelium-independent manner. Indomethacin augmented the contra
ctile 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 H-1-receptor antag
onist, mepyramine nor significantly augmented by the neutral endopepti
dase inhibitor, phosphoramidon. 3 The contractile response to poly-L-a
rginine was inhibited in a concentration-dependent manner by prior inc
ubation of guinea-pig tracheal rings with a number of anionic polypept
ides including, low molecular weight heparin, poly-L-aspartic acid and
bovine serum albumin. 4 In vitro capsaicin-induced desensitization fa
iled to attenuate the contractile response to poly-L-arginine, suggest
ing little, if any role for sensory neuropeptides in the functional re
sponse in the guinea-pig. 5 Synthetic polypeptides induce an epitheliu
m-independent, charge-dependent contraction of guineapig isolated trac
hea.