Effect of Heart Failure on Dipeptidyl Peptidase IV Activity in Plasma of Dogs

Abstract

Background: In congestive heart failure (HF), plasma B-type natriuretic peptide (BNP) seems devoid of biological effectiveness. BNP1-32 could be truncated into BNP3-32 by dipeptidyl peptidase IV (DPP4), and BNP3-32 has reduced biological activities. Hypothesis: Increased DPP4 activity is associated with pathophysiology of HF. Animals: One hundred twenty-eight client-owned dogs and 9 experimental Beagles from the Clinical Veterinary Unit of the University of Liège. Methods: We prospectively measured plasma DPP4 activity in 5 groups of dogs: normal growing dogs (n = 21), normal adult dogs (n = 60), healthy Beagle (n = 9), dogs with myxomatous mitral valve disease (n = 35), and dogs with dilated cardiomyopathy (n = 12). The final diagnosis and the severity of HF were determined by Doppler echocardiography. Plasma DPP4 activity was measured kinetically by a fluorimetric method. Results: In growing dogs, DPP4 activity was higher than in adults (P < .001) and inversely correlated with age (r = -0.57, P < .01). In adults, DPP4 activity increased linearly with body weight (r = 0.39, P