The effects of L-ascorbic acid and prostaglandins on isolated tracheal smooth muscle

On the isolated tracheal smooth muscle, L-ascorbic acid alone induced a dose-related relaxation. When L-ascorbic acid was added in a standard concentration of 10(-5) g/ml to increasing concentrations of PGE2, an increase of relaxation was evident. The opposite effect was observed when PGF2 alpha was added in presence of L-ascorbic acid: a depression of tracheal smooth muscle contraction occurred. L-ascorbic acid increased the relaxing effect of isoprenaline on the tracheal smooth muscle. The relaxation effect of L-ascorbic acid was abolished by propranolol. These data support the hypothesis, that the effect of L-ascorbic acid may be related to stimulation of beta adrenergic receptors.