ENHANCEMENT OF THE RENAL EXCRETION OF CESIUM-137 IN RATS TREATED WITH ACETAZOLAMIDE AND RELATED COMPOUNDS

Journal Article · Tue Dec 31 23:00:00 EST 1963 · J. Pharmacol. Exptl. Therap.

OSTI ID:4051517

Sastry, B V.R.; Bush, M T

Since Cs and K are closely similar in physicochemical properties and therefore handled similarly physiologically, agents effective in increasing K excretion were tested for ability to increase excretion of /sup 137/Cs, a major fallout radionuclide. In rats the renal excretion of /sup 137/Cs was shown to be increased by carbonic anhydrase inhibitors (acetazolamide, ethoxzolamide), inhibitors of the H/sup +/ exchange system (maleate) and materials producing hyperchloremic acidosis (ammonium chloride). The results indicate that Cs/sup +/ substitutes for K/sup +/ in the H/sup +/ exchange system. Metalluride blocked the effect of acetazolamide on /sup 137/Cs excretion without influence on urine volume and pH. This indicates that acetazolamide increases the urinary excretion of /sup 137/Cs by increasing its secretion through the renal tubule in the same manner as it increases excretion of K. Metabolic acidosis nullified the effect of acetazolamide on /sup 137/Cs excretion. Rats treated with ammonium chloride and ammonium chloride followed by acetazolamide excreted equal amounts of /sup 137/Cs. Repeated doses of acetazolamide did not increase /sup 137/Cs excretion, which is similar to the influence of the repeated doses of acetazolamide on K excretion. A relation was noted between the activities of the structural analogs of acetazolamide in their inhibition of carbonic anhydrase and their efficacies for increasing the urinary excretion of /sup 137/Cs. Clinical doses of the very active carbonic anhydrase inhibitors, ethoxzolamide and acetazolamide, increased / sup 137/Cs excretion for 6 hours. Chlorothiazide is a weak carbonic anhydrase inhibitor, and large doses increased the /sup 137/Cs excretion only for the first hour. Clinical doses of hydrochlorothiazide, which do not inhibit carbonic anhydrase, did not increase /sup 137/Cs excretion. Maleate increased /sup 137/Cs and bicarbonate in urine for 6 hours. Acetazolamide increased /sup 137/Cs excretion and thereby decreased the retention in the muscle. Chlorothiazide increased /sup 137/Cs excretion during the first hour, but its cumulative effect was to decrease /sup 137/Cs excretion, and thereby favor accumulation of higher concentrations of /sup 137/Cs in the skeletal muscle. These findings indicate that the excretions of /sup 137/Cs and K are controlled by similar renal mechanisms, and the /sup 137/Cs excretion can be influenced effectively by pharmacologic agents. (BBB)

• Research Organization: Vanderbilt Univ., Nashville
• NSA Number: NSA-18-017439
• OSTI ID: 4051517
• Journal Information: J. Pharmacol. Exptl. Therap., Journal Name: J. Pharmacol. Exptl. Therap. Vol. Vol: 143
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ACETIC ACID
ACIDITY
AMIDES
AMMONIUM COMPOUNDS
BIOCHEMISTRY
BIOLOGY AND MEDICINE
CARBONATES
CESIUM 137
CHLORIDES
CHLOROTHIAZIDE
DECONTAMINATION
DRUGS
ENZYMES
HETEROCYCLICS
HYDROGEN
ION EXCHANGE
IONS
KIDNEYS
MALEIC ACID
METABOLISM
MUSCLES
ORGANIC ACIDS
ORGANIC CHLORINE COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PHYSIOLOGY
POTASSIUM
RATS
REACTION KINETICS
URINE
VARIATIONS