Andrew Brem, MD
Research within the division of pediatric nephrology focuses on the relationship between the local metabolism of selected steroids and the evolution of hypertension. Studies are being conducted both in sodium-transporting renal epithelial cells and in vascular tissue. This laboratory has documented and characterized the presence of glucocorticoid metabolism within vascular smooth muscle and vascular endothelial cells by the enzyme 11ß-OH steroid dehydrogenase. Enzyme direction and activity appear to determine whether endogenous glucocorticoids will bind to either glucocorticoid or mineralocorticoid receptors and induce a biologic response.
Glucocorticoids alone do not affect vascular contractile responses. However, vascular tissues chronically exposed to these steroids, in presence of inhibitors of 11ß-OH steroid dehydrogenase, show an enhanced contractile response to circulating vasoconstrictors like catecholamine and angiotensin II. In separate studies, this laboratory has also demonstrated the isoforms of 11ß-OH steroid dehydrogenase can modulate steroid induced sodium transport in renal epithelial cells.