[Phosphatase activity in the forearm bones of rats after a flight aboard the biosatellite "Cosmos-936"]

Activities of alkaline and acid phosphatases in ulnar and radial bones of rats flown for 18.5 days aboard Cosmos-936 and kept in a ground-based mock-up were investigated. In both bones activity of acid phosphatase increased significantly and that of alkaline phosphatase decreased 6--10 hours postflight; in the synchronous experiment the only change was a decrease in the activity of alkaline phosphatase in the radius. An exposure of rats to artificial gravity did not normalize changes in phosphatase activities observed postflight. At R + 25 phosphatase activity in bones of flight rats returned to normal and even tended to exceed the control level in synchronous animals.