Evaluation of Alacepril Administration in Canine Patent Ductus Arteriosus According to Plasma Chymase Activity

Simple Summary Chymase is a protease stored in mast cell granules and is released triggered by tissue, especially cardiovascular, damage. Many studies showed the potentials of measuring chymase activity for the prognostic factor. However, the mechanism of chymase in veterinary cardiac disease was unknown. Recently, the plasma chymase activity has become possible to measure. Moreover, in patent ductus arteriosus, a congenital heart disease with a high incidence in veterinary medicine, chymase activity was significantly high at the preoperative time. In the present study, the changes of plasma chymase activity were further investigated after medical therapy for preoperative cardiac disease. The measurement of plasma chymase activity may be a useful tool for diagnosing the pathophysiology and the effect of medical therapy.Abstract Chymase in the renin-angiotensin system (RAS) actively contributes to cardiac disease progression. Chymase is activated to produce angiotensin II during tissue injury and is involved in hemodynamics. A recent study demonstrated that plasma chymase activity reflects hemodynamic changes and aids in understanding patent ductus arteriosus (PDA) pathophysiology. The present study examined the relationship between plasma chymase activity and the administration of angiotensin-converting enzyme (ACE) inhibitor. Alacepril was administered to 13 puppies with PDA. Conventional echocardiographic parameters and non-invasive blood pressure were measured before and after medication. Plasma chymase activity was calculated using the colorimetric absorbance method. Plasma chymase activity significantly increased, but blood pressure significantly decreased. We detected an increase in plasma chymase activity due to ACE inhibition in PDA cases treated with alacepril. Plasma chymase activity was affected and altered by alacepril. In veterinary medicine, plasma chymase activity may be a novel method for assessing the pathology of and therapy for cardiac diseases.