Regulation of Regional Perfusion Distribution in the Lungs. Experimental Model and Effect of Alveolar Pressure

Effect of isoproterenol on regional pulmonary perfusion and its blockade by propranolol.

“…Judging from the fact that isoproterenol can reverse the hypoxia-induced regional pulmonary vasoconstriction, stimulation of the fl-adrenergic system can modify the pulmonary vascular response to alveolar hypoxia. Once the fl-adrenergic system is blocked, stimulation of the f3-adrenergic system by isoproterenol is no longer feasible, and pulmonary vascular responses to the regional 02 tensions occur as expected from the previous reports (Isawa et al 1978b(Isawa et al , 1979(Isawa et al , 1980. Porcelli and Bergofsky (1973) reported that enhanced pulmonary pressor responses to hypoxia occurred during fl-blockade, and they attributed this enhancement to the unmasking of additional but previously antagonized a-receptors.…”

Effect of aminophylline on regional perfusion distribution in the lungs.

“…The increased alveolar pressure decreases regional pulmonary perfusion distribution due to a mechanical compression of the pulmonary vascular beds 'Isawa et al 1978a). Alveolar hypoxia induces regional pulmonary vasocon ?triction, while alveolar hyperoxia causes regional pulmonary vasodilation and/or ?ascular recruitment (Isawa et al 1978b).…”

Effect of isoproterenol on regional pulmonary perfusion in the reimplanted lung of the dog.

“…The experimental procedures were the same as described previously (Isawa et al 1978a(Isawa et al ,, b, 1981. Especially the use of medications and the sequence of studies were the same as adopted in the normal dogs as reported previously (Isawa et al 1981) so that comparison of the data was possible between the normal and the denervated lung lobes.…”