Effect of metabolic acidosis on pulmonary microcirculation in the cat.

Using a new X-ray TV system, we studied the effects of metabolic acidosis, produced by intravenous injection of lactic acid, on internal diameter (ID; 100-500 micron), flow velocity, and volume flow in pulmonary microcirculation of anesthetized cats. We found that metabolic acidosis decreased the ID of arteries by 21%, whereas it increased flow velocity by 28% but not volume flow.