The effects of halothane on the DNase I activity in an isolated enzyme preparation and in the DNase I-G actin complex

Abstract

The effects of halothane on the DNase I activity in an isolated enzyme preparation and in a DNase I-globular (G) actin complex was investigated. DNase I, DNase I-G actin complexes and G actin were exposed to various (0.2–4.0 vol./%) halothane concentrations for 3 h. Thereafter, DNase I was mixed with a DNA solution and the extinction of the acid soluble supernatant of the DNase I assay was determined as a measure of DNase I activity. After 10 min of halothane exposure the DNase I activity is inhibited in direct proportion to halothane concentrations between 0.6 and 4.0 vol/%. After 10 min halothane activates inactive DNase I by inhibiting G actin, an inhibitor of DNase I. G actin, exposed to halothane, does not inhibit the activity of DNase I. The results suggest a mechanism by which halothane may contribute to chromosomal defects and disturbances of DNA metabolism in cells.