Retinoic Acid Supplementation Attenuates Ventricular Remodeling after Myocardial Infarction in Rats

Abstract

The objective of this study was to evaluate the role of retinoic acid in experimental postinfarction myocardial remodeling. Wistar rats were subjected to myocardial infarction (MI) and treated with retinoic acid (RA), 0.3 mg/(kg x d) (MI-RA, n = 29), or fed a control diet (MI, n = 34). After 6 mo, the surviving rats (MI-RA = 18 and MI = 22) underwent echocardiograms, and isolated hearts were tested for function in vitro. The cross-sectional area of the myocyte (CSA) and interstitial collagen fraction (IC) were measured in a cross section of the heart stained by hematoxylin-eosin and picrosirius red, respectively. The CSA was smaller in the MI-RA group [229 (220,234) microm2] [medians (lower quartile, upper quartile)] than in the MI group [238 (232,241) microm2] (P = 0.01) and IC was smaller in the MI-RA group [2.4 (1.7, 3.1)%] than in the MI group [3.5 (2.6, 3.9)%] (P = 0.05). The infarct size did not differ between the groups [MI = 44.6 (40.8, 48.4)%, MI-RA = 45 (38.6, 47.2)%]. Maximum rate of rise of left ventricular pressure (+dp/dt) was greater in the MI-RA group (2645 +/- 886 mm Hg/s) than in the MI group (2081 +/- 617 mm Hg/s) (P = 0.05). The other variables tested did not differ between groups. Retinoic acid supplementation of rats for 6 mo attenuates the ventricular remodeling process after MI.

Retinoic acid and sodium butyrate suppress the cardiac expression of hypertrophic markers and proinflammatory mediators in Npr1 gene-disrupted haplotype mice

“…Our findings are consistent with previous reports that an RA-mediated effect suppresses the hypertrophy of myocardial cells (48,74). Chronic RA treatment has been shown to prevent ventricular fibrosis and improve impaired systolic heart function in rodent models of myocardial infarction (37,47). Furthermore, the treatments with RA and SB protected the heart against fibrosis (15,35,62).…”

13-cis-Retinoic acid specific down-regulation of angiotensin type 1 receptor in rat liver epithelial and aortic smooth muscle cells

“…The atRA treatment significantly attenuated the expression of the hypertrophic effects after AngII exposure. In a related study involving an in vivo model, retinoic acid significantly attenuated ventricular remodeling after myocardial infarction, a process known to be enhanced by AngII stimulation (Paiva et al 2005). It has been reported that MAP kinase phosphatases are up-regulated during atRA treatment (Palm-Leis et al 2004).…”

Infarto do miocárdio experimental em ratos: análise do modelo

“…For the functional assessment, several methods are available: analysis by the papillary muscle 60 , isolated heart 61,62 and invasive hemodynamic evaluation 12,63 . In the recent years, however, the echocardiogram has become increasingly important in the morphological and functional assessment of infarcted rats.…”