[The effect of head-down hypokinesia on functional state of diaphragm in rats].
The effects of long-term (21 days) head-down (-30 degrees) hypokinesia (HDH) on respiratory system and a functional state of diaphragm were investigated in rats. Minute ventilation, oesophageal and abdominal pressure, integrated electrical activity of diaphragm were measured in control and experimental group (after 21 days of HDH) of animals. The measurements were made in several body positions atresting and in occlusion breathing. The results indicate that HDH causes reduction in minute ventilation of lungs, decrease in orthostatic stability and functional reserve of the respiratory system capacity. It was established that the basic mechanism of HDH respiratory effects is contractile failure of diaphragm related to damage in excitation-contraction coupling in its muscular fibres.
Aleksandrova
N P
NP
Baranov
V M
VM
Tikhonov
M A
MA
Kolesnikov
V I
VI
Kotov
A N
AN
Kochanov
V S
VS
D000818:Animals; D003964:Diaphragm / Q000503:physiopathology*; D018475:Head-Down Tilt; D018476:Hypokinesia / Q000503:physiopathology*; D009119:Muscle Contraction; D051381:Rats; D017208:Rats, Wistar; D012143:Respiratory Physiological Phenomena; D012137:Respiratory System / Q000503:physiopathology*; D018474:Weightlessness Simulation