Role of calcium on protein phosphorylation in collagen-stimulated platelets. Effect of a new dihydropyridine derivative.
We investigated the effect of extracellular calcium on protein phosphorylation stimulated by collagen in rabbit platelets. We found that collagen-induced increase in 40 kDa protein phosphorylation was maximum at 2 mM Ca2+, and was evident in buffer with zero Ca2+ but not in the presence of EGTA. We also studied the effects of a new dihydropyridine derivative, which has antithrombotic properties, on protein phosphorylation induced by collagen. This compound inhibited the phosphorylation of 40 kDa and 20 kDa protein independently of the extra-cellular Ca2+. The inhibitory effect was dose-dependent but not time-dependent and was more evident when the drug was added before or simultaneously with collagen.
Catalán
R E
RE
Departamento de Biología Molecular, Universidad Autónoma de Madrid, Spain.
Martínez
A M
AM
Aragonés
M D
MD
Encabo
P
P
Hernández
F
F
D000818:Animals; D001792:Blood Platelets / Q000378:metabolism*; D002118:Calcium / Q000494:pharmacology*; D003094:Collagen / Q000494:pharmacology*; D004095:Dihydropyridines / Q000494:pharmacology*; D010766:Phosphorylation; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors; D011817:Rabbits
D004095:Dihydropyridines; D010975:Platelet Aggregation Inhibitors; C038806:1,4-dihydropyridine; D003094:Collagen; D002118:Calcium