Platelet secretion (exocytosis) is critical in amplifying platelet activation, in stabilizing
thrombi, and in arteriosclerosis and vascular remodeling. The signaling mechanisms
leading to secretion have not been well defined. We have shown previously that cGMP-
dependent protein kinase (PKG) plays a stimulatory role in platelet activation via the
glycoprotein Ib-IX pathway. Here we show that PKG also plays an important stimulatory role
in mediating aggregation-dependent platelet secretion and secretion-dependent second …