Beta-carotene supplementation results in adverse ventricular remodeling after acute myocardial infarction.
OBJECTIVE
We studied the effects of beta-carotene (BC) on ventricular remodeling after myocardial infarction.


METHODS
Myocardial infarction was induced in Wistar rats that were then treated with a BC diet (500 mg/kg of diet per day; MI-BC; n = 27) or a regular diet (MI; n = 27). Hearts were analyzed in vivo and in vitro after 6 mo.


RESULTS
BC caused decreased left ventricular wall thickness (MI = 1.49 +/- 0.3 mm, MI-BC = 1.23 +/- 0.2 mm, P = 0.027) and increased diastolic (MI = 0.83 +/- 0.15 cm2, MI-BC = 0.98 +/- 0.14 cm2, P = 0.020) and systolic (MI = 0.56 +/- 0.12 cm2, MI-BC = 0.75 +/- 0.13 cm2, P = 0.002) left ventricular chamber areas. With respect to systolic function, the BC group presented less change in fractional area than did controls (MI = 32.35 +/- 6.67, MI-BC = 23.77 +/- 6.06, P = 0.004). There was no difference in transmitral diastolic flow velocities between groups. In vitro results showed decreased maximal isovolumetric systolic pressure (MI = 125.5 +/- 24.1 mmHg, MI-BC = 95.2 +/- 28.4 mmHg, P = 0.019) and increased interstitial myocardial collagen concentration (MI = 3.3 +/- 1.2%, MI-BC = 5.8 +/- 1.7%, P = 0.004) in BC-treated animals. Infarct sizes were similar between groups (MI = 45.0 +/- 6.6%, MI-BC = 48.0 +/- 5.8%, P = 0.246).


CONCLUSIONS
Taken together, these data suggest that BC has adverse effects on ventricular remodeling after myocardial infarction.
Zornoff
Leonardo A M
LA
Faculdade de Medicina, Departamento de Clinia Medica, Botucatu, Sao Paulo, Brazil. lzornoff@fmb.unesp.br
Matsubara
Beatriz B
BB
Matsubara
Luiz S
LS
Azevedo
Paula S
PS
Minicucci
Marcos F
MF
Campana
Alvaro O
AO
Paiva
Sergio A R
SA
D000818:Animals; D000975:Antioxidants / Q000009:adverse effects* / Q000494:pharmacology; D019587:Dietary Supplements; D006321:Heart / Q000033:anatomy & histology; D008297:Male; D009203:Myocardial Infarction / Q000473:pathology*; D009206:Myocardium / Q000473:pathology; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D016896:Treatment Outcome; D016276:Ventricular Function / Q000187:drug effects / Q000502:physiology; D020257:Ventricular Remodeling / Q000187:drug effects*; D019207:beta Carotene / Q000009:adverse effects* / Q000494:pharmacology
D000975:Antioxidants; D019207:beta Carotene