Mechanism for the paradoxical aciduria following alkali administration to prolonged-fasted patients.
Rapidly induced systemic alkalinization due to either sodium-lactate or sodium-bicarbonate infusion in prolonged-fasted subjects with steady-state ketoacidosis was associated with a decrease in urine pH. This decrease in urine pH from 5.50 to 5.20 was the result of a significant decrease in urinary ammonium excretion from 8.40 to 6.35 mEg/hr and was not accompanied by an increase in net acid excretion (11.3 vs. 10.6 mEg/hr). The decreased ammonium excretion is attributed to the raised pH of the proximal tubular fluid resulting in a less favorable pH gradient for gaseous ammonia entry. This would decrease gaseous ammonia generated in the loop of Henle for collecting duct buffering of secreted hydrogen ions.
D000138:Acidosis / Q000209:etiology*; D000293:Adolescent; D000328:Adult; D000468:Alkalies / Q000627:therapeutic use*; D001639:Bicarbonates / Q000627:therapeutic use; D005215:Fasting; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007662:Ketosis / Q000188:drug therapy / Q000209:etiology* / Q000652:urine; D007687:Kidney Tubules, Proximal / Q000503:physiopathology; D007773:Lactates / Q000627:therapeutic use; D008138:Loop of Henle / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000628:therapy; D000644:Quaternary Ammonium Compounds / Q000652:urine; D012964:Sodium / Q000627:therapeutic use; D013997:Time Factors; D014556:Urine
D000468:Alkalies; D001639:Bicarbonates; D007773:Lactates; D000644:Quaternary Ammonium Compounds; D012964:Sodium