Pulmonary capillary pressure in intact dog lungs.

We used a gravimetric method to determine the ratio (gamma) of pulmonary venous to total pulmonary vascular resistance in intact dog lungs. From this ratio, pulmonary capillary pressure (Pc) can be calculated. The average value of gamma was 0.50 +/- 0.06 (mean +/- SD) in 10 dogs. We found no correlation between gamma and PO2, PCO2, pH, or hematocrit in the narrow ranges of these experiments. Over the capillary pressure range of 22.4--35.2 mmHg we found no correlation between gamma and Pc. The value of gamma found in this study is not significantly different from the value found in isolated perfused lungs.