EFFECT OF ASCORBIC-ACID ON RESPONSE TO METHACHOLINE CHALLENGE IN ASTHMATIC SUBJECTS

Abstract
The effect of ascorbic acid was studied in 14 mild asthmatic [human] subjects. The effect of ascorbic acid (1.0 g orally) was assessed by the changes in concentration of methacholine required to decrease the specific airway conductance by 40% (pD40). Ascorbic acid increased pD40 from control values of 9.38 .+-. 1.97 mg/ml (mean .+-. SEM [standard error of the mean]) to 12.59 mg/ml .+-. 2.52 (P < 0.05). Administration of 50 mg of indomethacin, orally, reversed the effect of ascorbic acid. Indomethacin alone had no effect on the mean pD40. Apparently, ascorbic acid exerts its effect via alteration of arachidonic acid metabolism.