Ammonia-induced change in the hepatic glutathione level of an air-breathing freshwater teleost Channa punctatus (Bloch).

Exposure to ammonia (NH4OH) for 48 h resulted in greater than 50% depletion of the hepatic glutathione pool in Channa punctatus (Bloch). Removal of fish to ammonia free ambience induced a rapid and excessive resynthesis of glutathione within 24 h. This level, however, decreased within 5 days of return to ammonia-free fresh water. It is concluded that ammonia stress in a freshwater air-breathing teleost is counteracted by the glutathione system of detoxication of xenobiotics and resynthesis of glutathione is induced by short-term exposure to ammonia followed by transfer to ammonia-free water.