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Roles of myosin light-chain kinase in platelet shape change and aggregation.
- Source :
-
Biochimica et biophysica acta [Biochim Biophys Acta] 1994 Sep 08; Vol. 1223 (2), pp. 163-9. - Publication Year :
- 1994
-
Abstract
- We examined the roles of myosin light-chain kinase in platelet responses to ADP using wortmannin, which almost completely inhibited myosin light-chain kinase at 3-6 microM. This concentration of wortmannin did not affect ADP-induced changes in the shape of the platelets, but it markedly inhibited aggregation in platelet-rich plasma and washed platelets. ML-9, another inhibitor of myosin light chain kinase, elicited similar effects on the platelet responses to wortmannin. Electron microscopic studies showed that there was no wortmannin effect on the ADP-induced spheration of discoid platelets, pseudopod formation, or granule centralization. Wortmannin at concentrations which prevented myosin light-chain kinase also inhibited platelet aggregation induced by ADP in the presence of U46619, an analogue of thromboxane A2, which is a prerequisite for ADP-induced irreversible aggregation. Although wortmannin partially inhibited protein kinase C, the protein kinase C inhibitor Ro-31-7549 (5 microM) prevented neither ADP- or ADP/U46619-induced changes in the shape of the platelets nor aggregation. These results suggest that myosin light-chain kinase activation is a prerequisite for ADP-induced platelet aggregation, but not for changes in their shape.
- Subjects :
- Adenosine Diphosphate pharmacology
Androstadienes pharmacology
Blood Platelets drug effects
Blood Platelets ultrastructure
Cell Size
Enzyme Activation
Humans
Myosin-Light-Chain Kinase antagonists & inhibitors
Platelet Aggregation drug effects
Wortmannin
Blood Platelets physiology
Myosin-Light-Chain Kinase physiology
Platelet Aggregation physiology
Subjects
Details
- Language :
- English
- ISSN :
- 0006-3002
- Volume :
- 1223
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Biochimica et biophysica acta
- Publication Type :
- Academic Journal
- Accession number :
- 8086484
- Full Text :
- https://doi.org/10.1016/0167-4889(94)90222-4