[Functional capabilities of the papillary muscles of the left heart in rats during adaptation to high altitude conditions].

The amplitude of papillary muscles shortening at gradual increase of the rate of stimulation from 12 to 60, 120 180/min in conditions of permanent high altitude hypoxia on 3rd, 15th, 30th, and 45th day of adaptation noticeably increased at 180/min stimulation starting from the 15th day of mountain exposure and remaining till the 30th and 45th day. The performance of the muscles had been considerably decreased as compared with the control tests, on the 3rd day of adaptation.