E. Sipahi et Zs. Ercan, THE MECHANISM OF THE RELAXING EFFECT OF ASCORBIC-ACID IN GUINEA-PIG ISOLATED TRACHEAL MUSCLE, General pharmacology, 28(5), 1997, pp. 757-760
1. The effect of ascorbic acid was studied in the guinea pig isolated
tracheal muscle. 2. Ascorbic acid with relatively higher concentration
s produced a dose-dependent relaxation in tracheal muscle submaximally
precontracted with KCl, histamine, and carbachol. 3. Removing the epi
thelium did not significantly alter the relaxing effect of ascorbic ac
id in histamine- and KCl-precontracted strips. 4. The relaxing effect
of ascorbic acid is stronger in carbachol-precontracted epithelium-den
uded strips than in epithelium-intact strips. 5. Indomethacin, but not
L-NAME, partially inhibited the relaxing effect of ascorbic acid. 6.
These results indicate that the relaxation induced by ascorbic acid in
guinea pig isolated tracheal muscle does not fully depend on the pres
ence of epithelium but is partially mediated by the production of pros
tanoids from smooth muscle. (C) 1997 Elsevier Science Inc.