Effects of endosulfan on fish carbohydrate metabolism

Abstract

Exposure of the Indian catfish ( Heteropneustes fossilis) to a high sublethal concentration of 0.0015 ppm (0.75 of the 96-hr LC 50) of endosulfan for 3, 6, 12, 48, and 96 hr affected carbohydrate metabolism. Muscle glycogen levels decreased significantly at 3, 6, 48, and 96 hr; liver glycogen content declined at 6 hr but there was a resynthesis of liver glycogen stores at 12 hr. Blood glucose levels in fish were elevated at 3, 6, 48, and 96 hr. Mean values of blood pyruvate were elevated significantly at 6 and 48 hr. Blood lactate levels were elevated at 3 and 6 hr but hypolacticemia resulted at 12 and 96 hr in pesticide-treated fish. The observed effects of endosulfan on carbohydrate metabolism in fish are discussed in relation to acute stress syndrome. Measurement of carbohydrate metabolites in fish for 3 hr or longer could prove useful as a rapid method for evaluating toxicity of pesticides and other toxicants.