Dexamethasone lacks effect on blood pressure in mice with a disrupted endothelial NO synthase gene.

Cushing's syndrome and systemic administration of glucocorticoids are associated with hypertension, but the underlying molecular mechanism is only partially understood. We have shown previously that dexamethasone downregulates the expression of the endothelial NO synthase (eNOS) gene in human endothelial cells and in the rat and that this may contribute to the blood pressure-raising effect of the steroid [Proc. Natl. Acad. Sci. USA 96 (1999) 13357]. In the current communication, we demonstrated that dexamethasone increased mean arterial blood pressure in wild-type C-57 Bl6 mice (eNOS+/+ mice), but had no effect on blood pressure in mice with a disrupted eNOS gene (eNOS-/- mice) derived from…