Methomyl induced effect on fortilin and S100A1 in serum and cardiac tissue: Potential biomarkers of toxicity.

Methomyl toxicity has been reported as a cause of several accidental and suicidal fatalities. The study is evaluating the effect of lethal methomyl toxicity on fortilin and S100A1 in serum and cardiac tissues. Adult 96 female Sprague-Dawley rats were divided equally into a control (euthanized by cervical dislocation) and a study group (overdosed with methomyl). The levels of fortilin and S100A1 in serum were measured antemortem (to establish the basal levels in serum) and postmortem (to evaluate changes after methomyl exposure) using enzyme-linked immunoassay. S100A1 was immunostained in sections from cardiac tissues. Both proteins in the control were not significantly different (p > 0.05) compared with the antemortem levels. On the contrast, both biomarkers levels in the intoxicated group were remarkably higher (p < 0.001) than the control and the antemortem levels. Ventricular tissues from the intoxicated rats presented depleted S100A1 immunostain in cardiomyocytes localized mainly in the epicardium with deeply stained adjacent cardiac fibroblasts. The cardiomyocytes were damaged with a prominent loss of striations compared to normal cardiac tissues from the control. The present outcomes explain to a certain degree the potential toxic effect of methomyl poisoning on the cardiac tissue. Both proteins could be added to the currently available battery of markers for assessing methomyl toxicity.