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PubMed1981

[Nitroglycerin also as a broncholytic].

0,8 mg nitroglycerin administered sublingually to 10 patients with asthma bronchiale and chronic obstructive pulmonary disease effects a reduction of airway resistance up to 21% in the second and fifth minute. Even one hour after application the oscillatory resistance (Ros) is 15% lower than at the beginning. In the same patients 0,4 mg inhaled fenoterol has a stronger effect (-30%). After intravenous administration of nitroglycerin (2,5 mg/h) over 15 minutes there is a significant decrease of the plethysmographic measured resistance (Rt) (-23%), an increase of the vital capacity and a decrease of the residual volume. Side effects are a small reduction of pO2 and blood pressure and an increase of heart rate. Orthostatic disturbances may occur. The venous lactate concentration does not change. The investigation shows that patients with obstructive airway disease may benefit from the application of nitroglycerin.

Airway Resistance↗

PubMedDate not supplied

Studies on the regulation of myocardial blood flow in man. I.: Training effects on blood flow and metabolism of the healthy heart at rest and during standardized heavy exercise.

In a comparative study 11 athletes and 11 untrained students were investigated at rest, of these 6 trained and 5 untrained individuals during exercise as well. Myocardial blood flow was measured by the argon method. Myocardial oxygen consumption, myocardial substrate uptake of glucose, lactate, and free fatty acids and cardiac output were determined by the direct Fick principle. Exercise was standardized according to 65% of an individual's maximal oxygen uptake (delta VO2 max). Coronary flow reserve was determined by dipyridamole injections. All measurements were made during hemodynamic and respiratory steady-state conditions with the subject in a supine position. At rest, myocardial blood flow and myocardial oxygen consumption were significantly lower in trained subjects compared to the untrained ones. These differences were more pronounced during heavy exercise. They cannot be explained completely by hemodynamic parameters. - During exercise, myocardial substrate uptake shifted to a predominant lactate uptake of almost 90% of total substrate uptake. Total substrate uptake as well as lactate uptake correlated significantly with myocardial oxygen. - Coronary flow reserve was lower in the trained group. It is concluded that the heart muscle of a trained individual requires less energy at a given work load than in the untrained state.

Adult↗