Y. Kawakami

Evaluation of aerosols of prostaglandins E1 and E2 as bronchodilators

SummaryAerosols of prostaglandin E1 (PGE1) and E2 (PGE2) were evaluated as bronchodilators in 32 subjects (6 normals, 15 with bronchial asthma and 11 with chronic bronchitis). PGE2 caused a significant decrease in pulmonary resistance (mean values 3.2 and 2.6 cm H2O/l/sec before and after inhalation, respectively). There were no significant changes in pulmonary resistance after PGE1. Bronchoconstriction occurred in some subjects whose pulmonary resistance had been within normal limits. Static pulmonary compliance did not show any definite change. The frequency dependence of dynamic compliance was measured in 19 subjects; in 3 the results suggested that bronchoconstriction after PGE1 preferentially affected small airways; in 1 other subject bronchodilatation occurred exclusively in the small airways. Arterial Po2 decreased in 4 out of 5 patients after inhalation of PGE1. This was thought to be due to greater unevenness of the ventilation perfusion ratio, since the dynamic pulmonary compliance became more dependent on respiratory frequency even though pulmonary resistance improved in these subjects. The pulse rate did not change significantly, but mean blood pressure decreased in 8 out of 15 subjects. Cough and irrtation of the pharynx were noted in 42 and 62 per cent of subjects during and after the inhalation of PGE1 and PGe2, respectively. Five and 23 percent of the subjects complained of headache after inhaling PGE1 and PGE2. The results suggest that aerosols of PGE2 have a bronchodilating action which could be of use in clinical practice, if untoward responses such as irritation of the pharynx, cough and headache could be avoided.

Changes in Potassium Content of Erythrocytes during Exercise in Man

Abstract. Factors affecting erythrocyte K+ content and plasma electrolytes during light exercise were examined in 8 normal subjects and 27 patients with chronic obstructive lung disease. The patients were classified into bronchitis, emphysema and intermediate groups. Arterial blood was obtained during rest, after 2, 5, and 7 min. of exercise on a bicycle ergometer (30 km/h without mechanical brake), and at 10 and 20 min. during recovery for analysis of PO2, PCO2, plasma H, Na+, K, and Cl‐, erythrocyte K+ content and whole blood lactate. Plasma H increased significantly in all subjects after 2 min. of exercise and PCO2 rose in normal, bronchitis, and emphysema groups during exercise, whereas PO2 did not change significantly. Plasma K rose promptly after the beginning of exercise and remained at high values during exercise. The rapid rise in PCO2 was associated with a significant decrease of calculated erythrocyte K in patients with chronic bronchitis. Although changes in plasma H were dependent on both PCO2 and lactate, erythrocyte K+ changes were significantly related only to changes in PCO2. These results indicate that the decrease in erythrocyte K+ is mainly controlled by changes in arterial PCO2 during light exercise in patients with chronic bronchitis.