Abstract
The objective of this study was to analyze the cardiac effects of exposure to monosodium glutamate for a period of 7 days alone and in combination with beta-carotene supplementation. Rats were allocated into: control (I), experimental group (II) exposed to 4 mg of monosodium glutamate for 7 days and experimental group (III) exposed to monosodium glutamate and 300 mg/kg/diet beta-carotene for 7 days. After three days of randomization, cardiac structure was assessed by electron microscopy. The myocardial cells after exposure to monosodium glutamate illustrated branching cytoplasmic network of cardiac muscle with cross striations which are retracted around the nuclei. These nuclei showed dense and electron dense heterochromatin that associated with nuclear covering and dense chromatin distributed in the nucleoplasm. Delicate supportive tissue filling the intercellular spaces containing blood was also seen. Ultrastructurally, vacuolation of the mitochondria with fragmentation of its cristae with loss of its striations were observed. The myofibrils were dissociated with irregularities of its sarcomere. Empty spaces in the cytoplasm with disrupted intercalated disc were observed. In beta-carotene plus monosodium glutamate, most fibers showed normal morphological aspects. In conclusion: One week monosodium glutamate exposure induces morphological cardiac alterations and beta-carotene supplementation attenuates this ventricular remodeling process.