Estrogen receptors alpha and beta mediate distinct pathways of vascular gene expression, including genes involved in mitochondrial electron transport and generation of reactive oxygen species.

Estrogen plays an important role in the regulation of vascular tone and in the pathophysiology of cardiovascular disease. Physiological effects of estrogen are mediated through estrogen receptors alpha (ERalpha) and beta (ERbeta), which are both expressed in vascular smooth muscle and endothelial cells. However, the molecular pathways mediating estrogen effects in blood vessels are not well defined.

Activation of heterotrimeric G proteins by a high energy phosphate transfer via nucleoside diphosphate kinase (NDPK) B and Gbeta subunits. Specific activation of Gsalpha by an NDPK B.Gbetagamma complex in H10 cells.

Formation of GTP by nucleoside diphosphate kinase (NDPK) can contribute to G protein activation in vitro. To study the effect of NDPK on G protein activity in living cells, the NDPK isoforms A and B were stably expressed in H10 cells, a cell line derived from neonatal rat cardiomyocytes. Overexpression of either NDPK isoform had no effect on cellular GTP and ATP levels, basal cAMP levels, basal adenylyl cyclase activity, and the expression of G(s)alpha and G(i)alpha proteins.