肺における血管作動性物質の作用におよぼす気管支動脈結紮の効果について

抄録

The effect of histamine, acetylcholine, serotonin and prostaglandin F_2α on the tracheobronchial tree, pulmonary circulation and systemic circulation before and after ligation of bronchial arteries was studied to examine the mechanism and site of action of these vasoactive substances in anesthetized dogs.
The left hemithorax was opened under artificial ventilation, bronchial arteries with their parent intercostal arteries were carefully dissected. Drugs were injected through catheters inserted into the right and left ventricle, respectively. The same injection was repeated after ligation of bronchial arteries. The data of intratracheal pressure (Ptr), pulmonary artery pressure (Ppa) and systemic arterial blood pressure (Psyst) before and after ligation of bronchial arteries were compared by Student's paired-t test.
1) The percent increase of Ptr after left ventricular injection of acetylcholine (200μg), serotonin (200μg) and prostaglandin F_2α (100μg), except histamine (200μg), was significantly attenuated by ligation of bronchial arteries.
2) The percent increase of Ptr after right ventricular injection of serotonin and prostaglandin F_2α, except acetylcholine and histamine, was attenuated significantly by ligation of bronchial arteries.
3) The influence of bronchial arteries ligation on increase of P_PA was observed following histamine injection only.
4) Ligation of bronchial arteries has no influence on the change of Psyst induced by these vasoactive substances.
The above results may suggest that acetylcholine, serotonin and prostaglandin F_2α act on relatively proximal portions of the airway, while histamine acts on relatively peripheral airway portions.