Paraquat myopathy: report on two suicide cases

We describe two suicide cases in which old paraquat was ingested. In conjun ction with lung involvement a pronounced degeneration was observed in skele tal muscle of one who died on the 14th day after the ingestion. The followi ng sarcoplasmic or endoplasmic reticulum Ca2+ ATPase (SERCA) monoclonal ant ibodies were used for skeletal muscle fiber typing by an immunohistochemica l method: NCL-SERCA1, reactive with type 2 fiber (fast-twitch), and NCL-SER CA2, reactive with type 1 fiber (slow-twitch). The examination revealed tha t the remarkably degenerated fibers belonged to type 1 muscle fibers. This case showed an abrupt increase of plasma CK levels (1796 mU/ml) on the fift h day after the ingestion. The authors presume that the damage to the skele tal muscle had occurred in this period. The degeneration of the muscle seem ed to be attributable to the long retention of paraquat in the tissue becau se these findings were not observed in the other case who died on the fifth day. Paraquat-induced myopathy may develop in prolonged paraquat poisoning . The examination of CK levels in plasma will be useful for diagnosis of da mage of skeletal muscle. (C) 1999 Elsevier Science Ireland Ltd, All rights reserved.