P: Microvascular pressures measured by micropuncture in isolated perfused lamb lungs

cular pressures measured by micropipettes in isolated edematous rabbit lungs. J. Appl. Physiol. 60(2): 539-545, 1986.-To study the mechanical effects of lung edema on the pulmonary circu-lation, we determined the longitudinal distribution of vascular resistance in the arteries, veins, and microvessels, and the distribution of blood flow in isolated blood-perfused rabbit lungs with varying degrees of edema. Active vasomotor changes were eliminated by adding papaverine to the perfusate. In three groups of lungs with either minimal [group 1, mean wet-to-dry weight ratio (W/D) = 5.3-+ 0.6 (SD), n = 71, moderate (group II, W/D = 8.5 t 1.2, n = lo), or severe (group III, W/D = 9.9 k 1.6, n = 5) edema, we measured by direct micropuncture the pressure in subpleural arterioles and venules (20-60 pm diam) and in the interstitium surrounding these vessels. We also measured pulmonary arterial and left atria1 pressures and lun