Human platelets activated by thrombin rapidly produce diglyceride from phosphatidylinositol (PI). Concomitantly, a protein having a molecular weight of about 40,000 is heavily phosphorylated and serotonin is released. These reactions are inhibited in parallel manners by sodium nitroprusside which elevates cyclic GMP. 8-Bromocyclic GMP also inhibits the reactions. Instead, both agents stimulate the phosphorylation of a distinct protein having a molecular weight of about 50,000. Since stimulants of platelets such as thrombin normally increase cyclic GMP, the results imply that this cyclic nucleotide may be involved in a circuit leading to the feedback inhibition of PI hydrolysis presumably through protein phosphorylation.
|Number of pages||7|
|Journal||Biochemical and Biophysical Research Communications|
|Publication status||Published - 16-07-1981|
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cell Biology