[Does calmodulin participate in the regulation of the Ca-pump of erythrocytes in vivo?].
Using a highly effective chelator of Ca2+ and 45Ca, the concentration of Cai2+ in human and rat erythrocytes was measured both at normal and accelerated Ca2+ influx into the cells. No effect of the calmodulin-dependent reaction inhibitor R24571 was observed. The Ca-ATPase from saponin-treated erythrocytes was characterized by a high affinity for Ca2+ (K 0.5-0.7 microM). This value is 2-3 times as low as that for Ca2+ concentration causing a 50% increase of the Ca-ATPase activity in erythrocyte ghosts obtained during hypoosmotic hemolysis. The Ca-ATPase activity in saponin-treated erythrocytes did not change either under the effect of calmodulin or by R24571. It was assumed that calmodulin did not participate in the regulation of the Ca2+-pump operation in erythrocytes in vivo.
Pokudin
N I
NI
Petruniaka
V V
VV
Orlov
S N
SN
D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002118:Calcium / Q000097:blood* / Q000378:metabolism; D000252:Calcium-Transporting ATPases / Q000097:blood; D002147:Calmodulin / Q000037:antagonists & inhibitors / Q000502:physiology*; D004910:Erythrocyte Membrane / Q000201:enzymology / Q000378:metabolism; D004912:Erythrocytes / Q000201:enzymology / Q000378:metabolism*; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D051381:Rats
D002147:Calmodulin; D007093:Imidazoles; C031938:calmidazolium; D000252:Calcium-Transporting ATPases; D002118:Calcium
Uchastvuet li kal'modulin v reguliatsii aktivnosti Ca-nasosa v éritrotsitakh in vivo?