Tissue Vitamin A Insufficiency Results in Adverse Ventricular Remodeling after Experimental Myocardial Infarction

Abstract

Background/Aims: The role of tissue vitamin-A insufficiency on post-infarction ventricular remodeling is unknown. We tested the hypothesis that cardiac vitamin A insufficiency on post-infarction is associated with adverse myocardial remodeling. Methods: After infarction, rats were allocated into two groups: C (controls, n=25); VA (dietary vitamin A restriction, n= 26). After 3 months, the animals were submitted to echocardiogram, morphometric and biochemical analysis. Results: Rats fed the vitamin-A-deficient diet had lower heart and liver retinol concentration and normal plasma retinol. There were no differences in infarct size between the groups. VA showed higher diastolic left ventricular area normalised by body weight (C= 1.81 ± 0.4 cm2/kg, VA= 2.15 ± 0.3 cm2/ kg; p=0.03), left ventricular diameter (C= 9.4 ± 1.4 mm, VA= 10.5 ± 1.2 mm; p=0.04), but similar systolic ventricular fractional area change (C= 33.0 ± 10.0 %, VA= 32.1 ± 8.7 %; p=0.82). VA showed decreased isovolumetric relaxation time normalised by heart rate (C= 68.8 ± 11.4 ms, VA= 56.3 ± 16.8 ms; p=0.04). VA showed higher interstitial collagen fraction (C= 2.8 ± 0.9 %, VA= 3.7 ± 1.1 %; p=0.05). There were no differences in myosin heavy chain expression, metalloproteinase 2 and 9 activation, or IFN-γ and TNF-α cardiac levels. Conclusion: Local tissue vitamin A insufficiency intensified ventricular remodeling after MI, worsening diastolic dysfunction.

Cardiac dysfunction in β-carotene-15,15′-dioxygenase-deficient mice is associated with altered retinoid and lipid metabolism

“…These investigators further proposed that ATRA signaling may play a role in regulating damage and repair during heart remodeling (5). Minicucci et al (26) reported that local heart retinoid insufficiency is associated with intensified ventricular remodeling after experimental myocardial infarction, worsening diastolic dysfunction. These differences were accompanied by an increase in BNP expression.…”

Cardiac Remodeling Induced by All-Trans Retinoic Acid is Detrimental in Normal Rats

“…Pressure values, maximum LV pressure decrease rate, and maximum LV pressure development rate were recorded. Procedures and measurements were performed according to a previously described method [22-24]. …”

Pamidronate Attenuates Diastolic Dysfunction Induced by Myocardial Infarction Associated with Changes in Geometric Patterning

“…Infarct size was calculated by dividing the endocardial and epicardial circumferences of the infarcted area by the total epicardial and endocardial ventricular circumferences. The measurements were performed on midventricular sections (5-6 mm from the apex) under the assumption that the left midventricular slice shows a close linear relation with the sum of the area measurements from all of the heart sections [25]. …”