Effects of different subchronic treatments with lindane on some brush border enzymes in rat jejunum.

Subchronic lindane (gamma-HCH) intoxication by oral or s.c. injection over 7 and 15 days, induced a significant inhibition in rat jejunum maltase activity when the pesticide was administered at doses of 20 mg/kg b. wt. However, maltase levels remained unaffected in those animals injected with 10 mg/kg of lindane. A longer period of s.c. lindane exposure (30 days) at doses of 10 mg/kg induced a significant decrease in maltase activity, although the injection of 20 mg/kg over the same period did not alter this enzyme activity. When this lindane dose was s.c. injected over 20 days a significant inhibition of maltase activity was observed. However no changes in this enzyme were found in rats injected over 25 days. This fact seems to suggest that between 20-25 days of pesticide exposure the organism develops possible regulatory mechanisms to counteract the alterations induced by this dose of lindane on maltase activity. Lactase and alkaline phosphatase activities were not altered by lindane action in different treatments performed. Sucrase activity was only altered in oral injected rats at doses of 20 mg/kg over 15 days. In conclusion, maltase activity seems to be more sensitive to lindane action than other brush border enzymatic proteins; lindane effects on this enzyme depend on the injected dose and the pesticide administration period duration.