[Response of the rat erythrocyte glycolytic system to hyperosmotic shrinkage].
Hyperosmotic shrinkage (adding 300 microM sucrose to isotonic medium) stimulates lactate and ATP accumulation in rat but not human erythrocytes in which ATP pool was preliminary depleted. Inhibitors of Na(+)-K(+)-2Cl(-)-cotransport, Na+/H(+)- exchange and Na(+)- pump known to be activated by hypertonic medium had no influence on volume-induced effect. EGTA (1 microM), Ca(2+)-ATPase inhibitor vanadate (200 microM) and antagonist of calmodulin R24571 (10 microM) suppressed the stimulation of glycolysis by 80 and 30%, respectively. Addition of 1 microM Ca2+ and 1 mM Ca(2+)-ionophore A23187 in Ca2+ free medium stimulated glycolysis by 20% at isotonic conditions while additional hyperosmotic shrinkage resulted in a two-fold activation. It is suggested that shrinkage regulates activity of glycolytic enzymes through the mechanism of intracellular signaling involving Ca2+.
Levko
A V
AV
Aksentsev
S L
SL
Gurlo
T G
TG
Konev
S V
SV
Orlov
S N
SN
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors; D002147:Calmodulin / Q000037:antagonists & inhibitors; D002352:Carrier Proteins / Q000037:antagonists & inhibitors; D004533:Egtazic Acid / Q000494:pharmacology; D004912:Erythrocytes / Q000378:metabolism*; D006019:Glycolysis; D006801:Humans; D007773:Lactates / Q000378:metabolism; D019344:Lactic Acid; D008565:Membrane Proteins / Q000037:antagonists & inhibitors; D009997:Osmotic Pressure; D051381:Rats; D017923:Sodium-Hydrogen Exchangers / Q000037:antagonists & inhibitors; D028021:Sodium-Potassium-Chloride Symporters; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors
D002147:Calmodulin; D002352:Carrier Proteins; D007773:Lactates; D008565:Membrane Proteins; D017923:Sodium-Hydrogen Exchangers; D028021:Sodium-Potassium-Chloride Symporters; D019344:Lactic Acid; D000001:Calcimycin; D004533:Egtazic Acid; D000255:Adenosine Triphosphate; D000252:Calcium-Transporting ATPases; D000254:Sodium-Potassium-Exchanging ATPase
Otvet glikoliticheskoĭ sistemy éritrotsitov krysy na giperosmoticheskoe szhatie.