title: Renal medullary 11 beta-hydroxysteroid dehydrogenase type 1 in Dahl salt-sensitive hypertension.
abstract: The Dahl salt-sensitive rat is a widely used model of human salt-sensitive forms of hypertension. The kidney plays an important role in the pathogenesis of Dahl salt-sensitive hypertension, but the molecular mechanisms involved remain a subject of intensive investigation. Gene expression profiling studies suggested that 11 beta-hydroxysteroid dehydrogenase type 1 might be dysregulated in the renal medulla of Dahl salt-sensitive rats. Additional analysis confirmed that renal medullary expression of 11 beta-hydroxysteroid dehydrogenase type 1 was downregulated by a high-salt diet in SS-13BN rats, a consomic rat strain with reduced blood pressure salt sensitivity, but not in Dahl salt-sensitive rats. 11 beta-Hydroxysteroid dehydrogenase type 1 is known to convert inactive 11-dehydrocorticosterone to active corticosterone. The urinary corticosterone/11-dehydrocorticosterone ratio as well as urinary excretion of corticosterone was higher in Dahl salt-sensitive rats than in SS-13BN rats. Knockdown of renal medullary 11 beta-hydroxysteroid dehydrogenase type 1 with small-interfering RNA attenuated the early phase of salt-induced hypertension in Dahl salt-sensitive rats and reduced urinary excretion of corticosterone. Knockdown of 11 beta-hydroxysteroid dehydrogenase type 1 did not affect blood pressure in SS-13BN rats. Long-term attenuation of salt-induced hypertension was achieved with small hairpin RNA targeting renal medullary 11 beta-hydroxysteroid dehydrogenase type 1. In summary, we have demonstrated that suppression of 11 beta-hydroxysteroid dehydrogenase type 1 expression in the renal medulla attenuates salt-induced hypertension in Dahl salt-sensitive rats.
authors.affiliation: Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA.
authors.forename: Yong
authors.initials: Y
authors.lastname: Liu
authors.forename: Ravinder J
authors.initials: RJ
authors.lastname: Singh
authors.forename: Kristie
authors.initials: K
authors.lastname: Usa
authors.forename: Brian C
authors.initials: BC
authors.lastname: Netzel
authors.forename: Mingyu
authors.initials: M
authors.lastname: Liang
mesh_terms: D043205:11-beta-Hydroxysteroid Dehydrogenase Type 1 / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D006973:Hypertension / Q000201:enzymology*; D007679:Kidney Medulla / Q000201:enzymology* / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D051381:Rats; D020303:Rats, Inbred Dahl; D017673:Sodium Chloride, Dietary / Q000378:metabolism / Q000494:pharmacology
chemical_list: D034741:RNA, Small Interfering; D017673:Sodium Chloride, Dietary; D043205:11-beta-Hydroxysteroid Dehydrogenase Type 1