Changes in Plasma Bradykinin Concentration and Citric Acid Cough Threshold at High Altitude

Changes in ventilatory threshold at high altitude: effect of antioxidants.

PURPOSE To investigate the effects of prolonged hypoxia and antioxidant supplementation on ventilatory threshold (VT) during high-altitude (HA) exposure (4300 m). METHODS Sixteen physically fit males (25 +/- 5 yr; 77.8 +/- 8.5 kg) performed an incremental test to maximal exertion on a cycle ergometer at sea level (SL). Subjects were then matched on VO2peak, ventilatory chemosensitivity, and b...

Citric acid cough threshold and airway responsiveness in asthmatic patients and smokers with chronic airflow obstruction.

The relation between citric acid cough threshold and airway hyperresponsiveness was investigated in 11 non-smoking patients with allergic asthma (mean FEV1 94% predicted) and 25 non-atopic smokers with chronic airflow obstruction (mean FEV1 65% predicted). Cough threshold was determined on two occasions by administering doubling concentrations of citric acid. Seven of the 11 asthmatic subjects ...

Cough threshold to citric acid in diabetic patients with and without autonomic neuropathy.

The cough reflex has been investigated in insulin dependent diabetic patients with and without autonomic neuropathy. The cough response to inhaled citric acid was determined in eight patients with diabetes who had severe autonomic neuropathy and compared with that in 10 who had no evidence of neuropathy. The patients with autonomic neuropathy had a higher median threshold for the cough response...

Cough frequency and cough receptor sensitivity to citric acid challenge during a simulated ascent to extreme altitude.

The aim of this study was to determine the frequency of cough and the citric acid cough threshold during hypobaric hypoxia under controlled environmental conditions. Subjects were studied during Operation Everest 3. Eight subjects ascended to a simulated altitude of 8,848 m over 31 days in a hypobaric chamber. Frequency of nocturnal cough was measured using voice-activated tape recorders, and c...

Respiratory Changes at High Altitude.