EFFECTS OF CARBON DIOXIDE UPON URINE FORMATION AND GLOMERULAR BLOOD FLOW

Abstract

Tensions of CO2 greater than 30% of an atm. inhibited urine formation in intact frogs. Pithed frogs, not breathing, and with one ureter cannulated, tended to become anuric at slightly lower CO2 tensions. In the renal glomeruli the blood flow was frequently reduced, and sometimes reversibly stopped. The slight decreases of arterial blood pressure and of heart rate observed did not fully account for the reductions of glomerular blood flow. The latent periods for the onset of anuria were very brief (2-8 min.) ; recovery of urine formation required 5-25 min. Blood could flow rapidly through the glomeruli while no urine was formed. It is suggested that under the influence of CO2 the pressures in the renal arterioles diminished out of proportion to the decrease of pressure in the aorta.