Effects of vascular pressure on the pulmonary microvasculature in isolated dog lungs

Publisher Website
Google Scholar
Abstract
The effects of short periods of high pulmonary vascular pressures on the filtration characteristics of the lung''s microcirculation were studied in isolated dog lungs. When left atrial pressures (Pla) were < 30 cmH2O, the capillary filtration coefficient (Kf,C) was not different from that of controls (0.192 .+-. 0.009 ml .cntdot. min-1 .cntdot. cmH2O-1 .cntdot. 100 g-1). In 17 of 23 observations, where Pla exceeded 55 cmH2O, Kf,C was at least 1.5 times control. In 10 of 13 lungs, Kf,C returned to control values within 2 h after the Pla increase. In the other 3 experiments, Kf,C did not return to control values. The filtration coefficient of pulmonary microvessels increases at high left atrial pressures (> 55 cmH2O) and may represent either a stretching of existing pores or opening of a few large pores.