Selective dietary potassium depletion and acid-base equilibrium in the rat.
K+ depletion of two kinds was induced in two groups of rats by selective dietary restriction for up to 5 weeks. Complete metabolic studies for H+, K+, Na+ and Cl- were carried out daily during weeks 1, 3 and 5. In control rats of group A (receiving K+ with sodium chloride), plasma pH (7.47) and HCO3- (25 mmol/l), as well TA (titratable acid)--HCO3- and NH+4 urinary excretion rates, were stable, while balances were nil for K+ and slightly positive for Cl-. In K+-deprived rats of group A receiving sodium chloride, a progressive metabolic alkalosis developed (plasma pH reached 7.57 and HCO3- 35.8 mmol/l by 5 weeks), and TA--HCO3- and NH+4 urinary excretion rates were not different from controls. Plasma K+ fell progressively from 4.20 to 2.20 mmol/l, with negative K+ balance. Balances for Na+ and H2O were highly positive and plasma renin activity and aldosterone decreased by week 5. Hypochloraemia developed with positive Cl- balance. In control rats of group B (receiving K+ with neutral sodium phosphate), a slight metabolic alkalosis developed, and TA--HCO3- excretion rate was increased compared with control rats of group A.(ABSTRACT TRUNCATED AT 250 WORDS)
D000136:Acid-Base Equilibrium; D000471:Alkalosis / Q000209:etiology; D000818:Animals; D001639:Bicarbonates / Q000097:blood; D002245:Carbon Dioxide / Q000097:blood; D002712:Chlorides / Q000097:blood; D008297:Male; D010100:Oxygen / Q000097:blood; D011188:Potassium / Q000097:blood; D011191:Potassium Deficiency / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000097:blood
D001639:Bicarbonates; D002712:Chlorides; D002245:Carbon Dioxide; D012964:Sodium; D011188:Potassium; D010100:Oxygen