It was reported that ethanol-induced bronchoconstriction was associated with elevated serum levels of acetaldehyde and histamine in Japanese asthmatic patients, but there is no study to investigate the airway response to acetaldehyde. We performed this animal study to test the hypothesis that acetaldehyde has the bronchospastic action via histamine release. First, we investigated the airway response to ascending doses (31.3, 62.5, 125, and 250 mM) of inhaled ethanol or acetaldehyde in guinea-pigs. Secondly, guinea-pigs pretreated with intraperitoneal injection of saline or 20 mg/kg diphenhydramine inhaled acetaldehyde. Finally, guinea-pigs pretreated with intraperitoneal injection of saline or 0.5 mg/kg atropine sulfate inhaled acetaldehyde. Inhalation of acetaldehyde, but not ethanol, caused bronchoconstriction in a dose-dependent manner. The bronchoconstriction induced by inhaled acetaldehyde was completely prevented by pretreatment with diphenhydramine. Atropine had no preventing effect against the acetaldehyde-induced bronchoconstriction. In conclusion, acetaldehyde has the bronchospastic action via histamine release in guinea-pigs. It is suggested that histamine H1-antagonists may be available for preventing alcohol-induced asthma.

Endothelial and vascular smooth muscle dysfunction of epicardial coronary arteries play a pivotal role in the pathogenesis of vasospastic angina (VSA). However, coronary microvascular (MV) function in patients with VSA is not fully understood. In the present study, subjects without coronary obstruction were divided into two groups according to the acetylcholine provocation test: VSA group (n = 29) and non-VSA group (n = 21). Hyperemic MV resistance (hMR) was measured using a dual-sensor (Doppler velocity and pressure)-equipped guidewire, and guidewire-derived hemodynamic parameters were compared. There were no between-group differences in clinical demographics, including potential factors affecting MV function (e.g., diabetes). Although coronary flow velocity reserve was similar between the two groups [2.4 ± 1.0 (VSA group) vs. 2.4 ± 0.9 (non-VSA group); P = 0.8], coronary vessel resistance and hMR were significantly elevated in the VSA group compared with the non-VSA group (2.6 ± 3.1 vs. 1.2 ± 0.8, P = 0.04; 1.9 ± 0.6 vs. 1.6 ± 0.5, P = 0.03, respectively). Coronary vasospasm, older age, E/e', and estimated glomerular filtration rate were significantly associated with MV dysfunction [defined as ≥ median value of hMR (1.6)] in univariate analysis. Coronary vasospasm most strongly predicted higher hMR in multivariate logistic regression analysis (odds ratio, 4.61; 95% confidence interval, 0.98-21.60; P = 0.053). In conclusion, coronary MV resistance is impaired in patients with VSA compared with non-VSA patients, whereas coronary flow velocity reserve is maintained at normal levels in both groups. In vivo assessment of hMR might be a promising index of coronary MV dysfunction in patients with VSA.

Abstract-Littleis known about the physiological role of surface active phos pholipids (SAP) in the central respiratory tract.In the present study, the effect of SAP on acid-inducing inhibition of particle transport by the tracheal mucociliary function was investigated in unanesthetized pigeons. SAP and acids were directly nebulized to the surface of the trachea.The composition of SAP was based on that of the pulmonary surfactant.The experiment was carried out under application of acetylcholine providing a constant mucociliary transport. SAP significantly diminished HCI and H2S04-inducing inhibitions of the mucociliary transport. Benzalkonium chloride also reduced the inhibition.The results suggest that SAP may be a protecting factor of the mucociliary clearance and that SAP may be con nected with hydrophobicity not only of the alveolar surface but of the tracheal epithelium.

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