Increased ACE Expression and iNOS Protein Levels in the Aorta of 2‐month‐old Syrian Cardiomyopathic Hamsters

Abstract

Endothelial dysfunction, increased ACE activity, and oxidative stress are present in 2‐month‐old Syrian cardiomyopathic hamsters (SCH) before the clinical manifestations of heart failure. To evaluate the mechanisms underlying vascular alterations at this early stage, we assessed RNA expression and protein levels of ACE, eNOS and iNOS in aortic tissue of SCH and age matched controls (CT). RNA expression was quantified with Real‐Time RT‐PCR and protein levels with Western blot. ACE RNA expression and protein levels were higher in SCH than in CT (141 % and 1.54 AU vs. 100% and 0.030 AU respectively, P<0.05). eNOS RNA was four‐fold higher in SCH than in CT (P<0.05), although no changes in protein levels were found. In contrast, iNOS RNA expression was significantly lower in SCH (38%) than in CT (100%), whereas protein levels were higher in SCH (0.416 AU) than in CT (0.155 AU)(N=6, P<0.05). Our results suggest that overactivation of vascular ACE combined with increased iNOS protein content are crucial in the etiology of the vascular abnormalities that precede cardiac dysfunction in young SCH. Supported by MBRS‐RISE R25‐GM061838.