Non-genomic effect of estradiol on plasma membrane calcium pump activity in vitro.

The aim of the presented study was to compare the effect of 17-beta-estradiol on the hydrolytic activity of plasma membrane calcium pump (PMCA) purified from excitable (rat cortical synaptosomes) and non-excitable (human erythrocytes) cells. Both types of cell membranes contained different composition of the PMCA isoforms. To elucidate if the hormone action could depend on structure of PMCA protein, we assayed the hormone effect on Ca(2+)-ATP-ases pretreated for 15 and 40 min with trypsin.