<b>CHARACTERIZATION OF RECOMBINANT ENDOTHELIN RECEPTOR TYPE B OVEREXPRESSED IN CHINESE HAMSTER OVARY </b><b>CELLS </b>

Abstract

The recombinant B type of endothelin (ET) receptor (ETB receptor) was expressed at high levels in Chinese hamster ovary (CHO) cells. The recombinant ETB receptor possessed biochemical characteristics of the endogenous ETB receptor with regard to affinities, specificities for ET isopeptides, and molecular mass. In the transfected CHO cells, high concentrations of ET (10-10 Mg) caused a rapid, transient increase in intracellular free Ca2+ concentrations ([Ca2"],) followed by a lower, sustained phase. In contrast, low concentrations of ET (g10_" M) induced only the sustained [Ca2+], phase. Removal of extracellular Ca2+ and the