Tyrphostin A23

Tyrphostin A23, also known as tyrphostin-23, belongs to a novel class of low molecular weight proteins that inhibit protein tyrosine kinase and block the EGF-dependent autophosphorylation of the receptor. The inhibitors can bind to the EGF receptor kinase domain with different affinities. It also inhibits PDGFR kinase. Tyrphostin A23 has been used to inhibit agonist-induced GP IIb-IIIa activation in permeabilized platelets and in other studies to block calcium channel currents in vascular smooth muscle cells. In human and rat adrenocrotical cell studies tyrphostin-A23 can improved steroid-hormone secretion. Tyrphostin A23 can also inhibit the internalization of (125)I-transferrin in Heb7a cells.