The calpastatin defect in hypertension is possibly due to a specific degradation by calpain.
Calpastatin activity, significantly reduced in erythrocytes of patients affected by essential hypertension, is restored to normal values by appropriate therapeutical treatments in a time-dependent fashion and in parallel with the decline in blood pressure. Evidence is also presented indicating that red cell calpastatin is degraded in human and rat red cells by homologous calpain, and that the rate of degradation is approx. 5-times higher in rat erythrocytes. Thus, increased proteolytic degradation catalyzed by calpain could explain both the decrease in the amount of calpastatin activity and the profound difference between the intracellular level of the calpain inhibitor observed in erythrocytes from patients with essential hypertension and the genetically hypertensive rats.
Salamino
F
F
Institute of Biological Chemistry, University of Genoa, Italy.
Sparatore
B
B
De Tullio
R
R
Pontremoli
R
R
Melloni
E
E
Pontremoli
S
S
D000818:Animals; D001794:Blood Pressure; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D002154:Calpain / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism; D006801:Humans; D006973:Hypertension / Q000378:metabolism* / Q000628:therapy; D007700:Kinetics; D051381:Rats
D002135:Calcium-Binding Proteins; C033668:calpastatin; D002154:Calpain