Effect of sodium ascorbate on rat uterus and guinea pig atria in vitro.

Sodium ascorbate, an antioxidant, has been reported to have a complex stimulating action on guinea pig ileal longitudinal smooth muscle (3.5-7). Acetylcholine-induced contractions are augmented (3,6) in small concentrations. Larger concentrations inhibit spasmogenic responses induced by acetylcholine, histamine and 5-hydroxytryptamine (2,3,5), potentiate the effect of DMPP on guinea pig ileum but potassium induced contractions are not altered (5). Large doses also inhibit the bronchospasm induced by histamine, bradykinin, 5-hydroxytryptamine (5-HT) and acetylcholine in guinea pigs and have been found to exert a beneficial effect in anaphylaxis (1,3).