Tissue vitamin A insufficiency results in adverse ventricular remodeling after experimental myocardial infarction.
OBJECTIVE
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.


CONCLUSIONS
Local tissue vitamin A insufficiency intensified ventricular remodeling after MI, worsening diastolic dysfunction.
Internal Medicine Department, Botucatu Medical School, UNESP-São Paulo State University, Botucatu, Brazil. minicucci@fmb.unesp.br
Marcos F
MF
Minicucci
Paula S
PS
Azevedo
Silvio A
SA
Oliveira
Paula F
PF
Martinez
Fernanda
F
Chiuso-Minicucci
Bertha F
BF
Polegato
Luis A
LA
Justulin
Luiz S
LS
Matsubara
Beatriz B
BB
Matsubara
Sergio A R
SA
Paiva
Leonardo A M
LA
Zornoff
D000818:Animals; D007371:Interferon-gamma / Q000378:metabolism; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology*; D018995:Myosin Heavy Chains / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D014463:Ultrasonography; D016277:Ventricular Function, Left / Q000502:physiology; D020257:Ventricular Remodeling; D014801:Vitamin A / Q000032:analysis / Q000097:blood / Q000502:physiology*
D014409:Tumor Necrosis Factor-alpha; D014801:Vitamin A; D007371:Interferon-gamma; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D018995:Myosin Heavy Chains