Influence of Carbon Dioxide Inhalation on Renal Circulation and Electrolyte Metabolism

Abstract

Kidney plays an important role to regulate, so-called "milieu interne" In the body. The purpose of this study is to investigate the change of electrolyte metabolism and renal circulation in state of respiratory acidosis induced by carbon dioxide inhalation. Material and Method Thirteen subjects with renal disease, the subjects with essential hypertension and six hospitalized normal subjects were observed for the study. Renal vein catheterization was performed. Arterial blood and renal venous blood were obtained from brachial artery and renal vein, before and during inhalation of 5% CO2 for 30 minutes. And plasma sodium, potassium, chloride and bicarbonate concentrations were determined respectively. Renal vascular resistance (RVR), renal vein pressure (RVP), renal plasma flow (RPF), renal blood flow (RBF), glomerular filtration rate (GFR), and filtration fraction (FF) were measured before and during CO2 inhalation. Results Carbon dioxide partial pressure (PCO2) was increased and pH was decreased by 5% CO2 inhalation both in arterial blood and renal venous blood in all subjects. Concentration of sodium, potassium and chloride of arterial blood and renal venous blood remained almost unchanged during CO2 inhalation in all subjects. On the other hand bicarbonate concentration increased in both arterial and venous blood. Renal arterio-venous concentration difference of sodium (a-v Na-diff.) was decreased by CO2 inhalation in the subjects with renal disease. A-v differences of potassium concentration (a-v K-diff.) and chloride (a-v Cl-diff.) had a tendency to decrease by CO2 inhalation in the subjects with advanced renal disease. A-v difference of bicarbonate concenration (a-v HCO-3-diff.) had a tendency to increase by CO2 inhalation in the subjects with advanced renal disease.