[Ca2+ transport by the skeletal muscle sarcoplasmic reticulum in rats after suspension of the hindlimbs].
The functional capacity of skeletal muscle SR was examined in the lateral gastrocnemius (LG) of rats submitted to 1-40-day of disuse produced by a hindlimb suspension (HS). The Ca uptake by SR was measured in homogenate of muscle by means fo Ca-selective electrode, and the time course of SR Ca(2+)-pump inactivation in tissue homogenates incubated at 45 degrees C was studied. There were po significant effects of hindlimb unweighting on muscular Ca pump during 1-14 days of HS. The amount of Ca uptake in SR of LG was about 41% higher in the HS group than in the control after 25 days of HS. After 40 days of HS, the activity of Ca(2+) transport increased by 58% in SR atrophied HS muscle compared with the control. The increased resistance of LG muscle SR Ca pump to thermal exposure was observed after HS. The possible reasons of muscular Ca-pump activation after HS were discussed.
Arkhipenko
Iu V
IuV
Popova
I A
IA
Stepanova
V V
VV
Sazontova
T G
TG
Meerson
F Z
FZ
D000818:Animals; D001692:Biological Transport; D001835:Body Weight; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000378:metabolism; D006614:Hindlimb; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012044:Regression Analysis; D012519:Sarcoplasmic Reticulum / Q000378:metabolism*; D013696:Temperature; D013997:Time Factors; D014893:Weightlessness / Q000009:adverse effects*
D000252:Calcium-Transporting ATPases; D002118:Calcium
Transport Ca2+ sarkoplazmaticheskim retikulumom skeletnykh myshts krys pri vesovoĭ razgruzke zadnikh konechnosteĭ.