Histochemical Effects of Diazinon on Reticulin and Fibrin Proteins in the Intestine and Kidney of Channa punctatus

The widespread and indiscriminate use of agricultural pesticides has resulted in significant ecological disturbances, particularly in aquatic environments where pesticide residues accumulate.Diazinon, a commonly used organophosphate insecticide, is known for its persistence and toxic effects on non-target organisms, including fish.The present study was conducted to evaluate the impact of Diazinon on two basic connective tissue proteins-reticulin and fibrin-in the intestine and kidney of the freshwater fish Channa punctatus.Healthy specimens were acclimatized and divided into control and experimental groups, each containing 20 fish.The experimental group was exposed to Diazinon at a concentration of 3.1 mg/L for 30 days, while the control group was maintained in normal tap water.After exposure, tissues (intestine and kidney) were processed for histochemical analysis using Gomori's Reticulin Method and Mallory's PTAH Method.Control fish exhibited strong and well-defined reticulin and fibrin reactions across tissue layers.In contrast, Diazinon-treated fish showed markedly reduced or feeble staining, demonstrating disruption and deterioration of these non-cellular connective tissue proteins.Reticulin fibers were significantly diminished in intestinal mucosa and submucosa as well as in renal tubules and glomeruli.Similarly, fibrin presence decreased prominently in both organs following pesticide exposure.The results indicate that Diazinon adversely affects structural proteins essential for tissue integrity, suggesting that prolonged exposure may lead to connective tissue damage and impaired organ function.Although the exact mechanism remains unclear, the findings support the growing concern regarding pesticide-induced histopathological changes in aquatic organisms and highlight the potential ecological risks associated with Diazinon contamination.