Behavior of the Nitrate Ion in the Dog

Abstract

The absorption, distr., fate, toxicity and effect on electrolyte balance of nitrate salts were studied in 30 expts. on 13 dogs. By using the Na salt, it was possible to vary the anion composition of body fluids without changing the cation. At doses as high as 41 meq./kg. intraven. and 20 meq./kg. orally, there were no evidences of toxicity, nor were there marked changes in blood pressure or renal hemo-dynamics. A slight increase in glomerular filtration rate and renal plasma flow was usually observed. The vol. of distr. of nitrate averaged 28% of body wt. The avg. rate of metabolic alteration as detd. from the slope of the plasma concn. curves in nephrectomized dogs was 0.016 meq./kg./hr. The amt. of administered nitrate recovered in the urine varied directly with the dose, reaching 80-90% with doses of 10 meq./kg. or more. The rate of excretion of Na administered with nitrate was much greater than its rate of excretion when given with chloride. With NaNO3 admn., as much as 40% more Na was excreted than was injected, bringing about loss of extracellular fluid.