TC-99M DMSA RENAL UPTAKE - INFLUENCE OF BIOCHEMICAL AND PHYSIOLOGIC FACTORS

  • 1 January 1981
    • journal article
    • research article
    • Vol. 22  (12) , 1054-1058
Abstract
Female Sprague-Dawley rats [38] were studied to determine the effects of tubular blockade and commonly encountered changes in hydration and acid-base balance, on the urinary excretion and renal localization of 99mTc dimercaptosuccinic acid (DSA). Additional rats [10] were studied to quantitate the in vivo protein binding of 99mTc DMSA, and a final group of 12 was used to quantitate DMSA distribution in animals with diminished functional renal mass. Both osmotic diuress and dehydration by H2O deprivation for 24 h resulted in a plasma clearance of DMSA slower than in control animals. Acid-base imbalances significantly affected the renal accumulation of DMSA, and acidosis was associated with markedly increased background due to increased liver accumulation. The protein-bound portion of 99mTc DMSA in the plasma was high, reaching 89% within the first 5 min, and rising very slightly [not significant] with time. The unbound portion of DMSA had a plasma clearance slightly higher than the GFR [glomerular filtration rate]. Ablation of large amounts of renal tissue, resulting in significant decreases in GFR, did not significantly affect the renal localization of DMSA in the intact portions of the kidneys. Commonly encountered changes in acid-base balance and hydration will significantly alter the biologic distribution of 99mTc DMSA. These factors should be controlled when carrying out clinical studies.