Determination of effect of aspirin and captopril on cat glomerular filtration rate using renovascular hypertension scintigraphy
Purpose: To compare the effects of aspirin and captopril on glomerular filtration rate (GFR) during renal perfusion scintigraphy in cats after experimentally-induced unilateral renal-artery stenosis.
Methods: Twenty mixed-breed adult cats weighing 3-4 kg were used. After conducting renal scintigraphy operations, their GFRs were measured by the method of Gate. Four days later, renovascular hypertension was induced through renal-artery stenosis by clipping half of the left renalarteries. Renal scintigraphy was conducted after four days. After confirming the presence of hypertension, the cats were divided into two groups of 10 animals each (aspirin and captopril groups, respectively). The drugs were administered orally to the groups. One hour later, scintigraphic operations were repeated under anaesthesia after injecting 2 mCi of the radiopharmaceutical, technetium-99m diethylene triamine pentaacetic acid (99mTc-DTPA), via the femoral vein as a bolus dose. In all groups, regions of interest (ROIs) were drawn and GFRs were measured by Gate method.
Results: Mean total GFR (both right and left kidneys) in operated animals treated with captopril was 5.459 ml/min while the mean value for the left kidney and right kidneys were 1.585 and 3.874 ml/min, respectively. In operated animals treated with aspirin, mean total GFR was 5.440 ml/min, while the values for the left kidney and right kidneys were 1.567 and 3.866 ml/min, respectively.
Conclusion: These results indicate that aspirin has similar reduction effect on GFRs and similar shape of renograms as captopril in cat renovascular hypertension scintigraphy. Thus, aspirin is a suitable substitute for captopril in the diagnosis of renovascular hypertension in renal scintigraphy.
Keywords: Aspirin, Captopril, Cat, Renovascular Hypertension, Scintigraphy