@article{oai:niigata-u.repo.nii.ac.jp:00006369,
 author = {Nakajima, Toshiaki and Ohdaira, Tetsuro and Satoh, Makoto and Kurashige, Kazuyuki and Yokota, Tatsuya and Suzuki, Eiichi and Kioi, Satoru and Arakawa, Masaaki},
 issue = {3},
 journal = {Acta medica et biologica, Acta medica et biologica},
 month = {Sep},
 note = {This study aims to elucidate the relationship between arterial plasma potassium concentration ([K^+]_a) and ventilation, and evaluate the effect of hyperoxia on the ventilation- [K^+]_a relationship during incremental exercise testing in patients with chronic obstructive pulmonary disease (COPD). We studied 16 male patients with COPD. Using a bicycle ergometer, each patient started to exercise with a work load of 25W, which was increased in steps of 5W in one minute intervals until the symptom-limited endpoint. The same trial with oxygen inhalation was also performed in 6 out of 16 patients. During the exercise testing in room air (n=16), [K^+]_a increased from the baseline (3.82 ± 0.18 mEq / L) to 4.62±0.33 mEq/L (p<0.01). Once exercise stopped, [K^+]_a decreased rapidly. In all patients, the increase in minute ventilation volume(V^^・_E) was significantly correlated with the elavation of [K^+]_a (p<0.05). Ventilatory response to [K^+]_a (the slope of △V_E/△K^+) varied markedly among the patients (13.1 to 50.7 L/min/mEq/L), and was correlated with forced vital capacity (FVC) (P< 0.05). During the trial with oxygen inhalation (n=6), the mean slope of △V^^・_E/△K^+ was not depressed, compared with the room air run, which was 21.9±11.9 in the former and 25.4±13.1 L/min/mEq/L in the latter, respectively. These findings indicate that: 1) ventilation and [K^+]_ a were correlated during exercise; 2) the slope of ventilatory response to [K^+]_a differed markedly among the patients, and was correlated with FVC; and 3) hyperoxia did not significantly affect the ventilation[K^+]_a relationship. We conclude that, while [K^+]_a may play some role, certain unknown factors may also be involved in determining the degree of exercise hyperpnea in patients with COPD.},
 pages = {81--87},
 title = {The Relationship between Arterial Plasma Potassium Concentration and Ventilation during Exercise in Patients with Chronic Obstructive Pulmonary Disease},
 volume = {46},
 year = {1998}
}