ascorbic-acid and Bronchial-Spasm

The effect of vitamin C pretreatment in preventing ragweed-induced bronchospasm was evaluated in 6 ragweed-sensitive asthmatics studied in a double-blind randomized fashion. The patients received either lactose capsules or 500 mg of ascorbic acid and were studied out of season. Antigen dose-response curves were determined prior to the administration of lactose or ascorbic acid in each individual subject and subsequently after administration of ascorbic acid or lactose. Bothe PD20FEV1 (provocation dose necessary for a 20% reduction in forced expiratory volume in 1 second) and PD35SGaw (provocation dose necessary for a 35% reduction in specific airways conductance) were determined. In none of the six patients was there a change in baseline FEV 1 (p greater than 0.70) nor the overall average baseline specific airways conductance (rho greater than 0.90). Additionally, no statistically significant difference (p greater than 0.60) was noted between log PD35SGaw vitamin C day and lactose day. Likewise, no statistically significant difference (p greater than 0.60) was evident when comparing log PD20FEV1 lactose and ascorbic acid days. Vitamin C (500 MG) HAS NO PROTECTIVE EFFECT AGAINST RAGWEED ANTIGEN-INDUCED BRONCHOSPASM.

Topics: Adult; Antigens; Ascorbic Acid; Bronchial Spasm; Clinical Trials as Topic; Dose-Response Relationship, Immunologic; Female; Forced Expiratory Volume; Humans; Lactose; Male

We have investigated the effects of ascorbic acid (1.0 gm orally) and indomethacin (50 mg orally) on airway tone in the basal state in six health nonsmoking male adults. Airway tone was assessed from measurements of specific airway conductance and flow rates interpolated from partial expiratory flow-volume curves by means of whole-body plethysmography and spirometry, respectively. Neither ascorbic acid nor indomethacin alone produced a significant change in basal tone. However, both the duration and intensity of the bronchoconstriction induced by methacholine aerosol (10 mg/ml for 30 sec) were significantly reduced by prior administration of ascorbic acid. This ameliorating action of ascorbic acid was blocked by ingestion of indomethacin. The results suggest that ascorbic acid exerts its effects by altering the production of a bronchodilator prostaglandin.

Topics: Airway Resistance; Ascorbic Acid; Bronchial Spasm; Humans; Indomethacin; Male; Methacholine Compounds; Peak Expiratory Flow Rate; Total Lung Capacity

Topics: Ascorbic Acid; Bronchial Spasm; Humans

Topics: Animals; Ascorbic Acid; Bradykinin; Bronchial Spasm; Epinephrine; Guinea Pigs; Histamine; Serotonin