TY - JOUR
T1 - Salt-sensitive hypertension in endothelin-B receptor-deficient rats
AU - Gariepy, Cheryl E.
AU - Ohuchi, Takashi
AU - Williams, S. Clay
AU - Richardson, James A
AU - Yanagisawa, Masashi
PY - 2000/4
Y1 - 2000/4
N2 - The role of the endothelin-B receptor (ET(B)) in vascular homeostasis is controversial because the receptor has both pressor and depressor effects in vivo. Spotting lethal (sl) rats carry a naturally occurring deletion in the ET(B) gene that completely abrogates functional receptor expression. Rats homozygous for this mutation die shortly after birth due to congenital distal intestinal aganglionosis. Genetic rescue of ET(B)(sl/sl) rats from this developmental defect using a dopamine - hydroxylase (DBH)-ET(B) transgene results in ET(B)-deficient adult rats. On a sodium-deficient diet, DBH- ET(B);ET(B)(sl/sl) and DBH-ET(B);ET(B)(+/+) rats both exhibit a normal arterial blood pressure, but on a high-sodium diet, the former are severely hypertensive. We find no difference in plasma renin activity or plasma aldosterone concentration between salt-fed wild-type, DBH-ET(B);ET(B)(+/+) or DBH-ET(B);ET(B)(sl/sl) rats, and acute responses to intravenous L-NAME and indomethacin are similar between DBH-ET(B);ET(B)(sl/sl) and DBH- ET(B);ET(B)(+/+) rats. Irrespective of diet, DBH-ET(B);ET(B)(sl/sl) rats exhibit increased circulating ET-1, and, on a high-sodium diet, they show increased but incomplete hypotensive responses to acute treatment an ET(A)- antagonist. Normal pressure is restored in salt-fed DBH-ET(B);ET(B)(sl/sl) rats when the epithelial sodium channel is blocked with amiloride. We conclude that DBH-ET(B);ET(B)(sl/sl) rats are a novel single-locus genetic model of severe salt-sensitive hypertension. Our results suggest that DBH- ET(B);ET(B)(sl/sl) rats are hypertensive because they lack the normal tonic inhibition of the renal epithelial sodium channel.
AB - The role of the endothelin-B receptor (ET(B)) in vascular homeostasis is controversial because the receptor has both pressor and depressor effects in vivo. Spotting lethal (sl) rats carry a naturally occurring deletion in the ET(B) gene that completely abrogates functional receptor expression. Rats homozygous for this mutation die shortly after birth due to congenital distal intestinal aganglionosis. Genetic rescue of ET(B)(sl/sl) rats from this developmental defect using a dopamine - hydroxylase (DBH)-ET(B) transgene results in ET(B)-deficient adult rats. On a sodium-deficient diet, DBH- ET(B);ET(B)(sl/sl) and DBH-ET(B);ET(B)(+/+) rats both exhibit a normal arterial blood pressure, but on a high-sodium diet, the former are severely hypertensive. We find no difference in plasma renin activity or plasma aldosterone concentration between salt-fed wild-type, DBH-ET(B);ET(B)(+/+) or DBH-ET(B);ET(B)(sl/sl) rats, and acute responses to intravenous L-NAME and indomethacin are similar between DBH-ET(B);ET(B)(sl/sl) and DBH- ET(B);ET(B)(+/+) rats. Irrespective of diet, DBH-ET(B);ET(B)(sl/sl) rats exhibit increased circulating ET-1, and, on a high-sodium diet, they show increased but incomplete hypotensive responses to acute treatment an ET(A)- antagonist. Normal pressure is restored in salt-fed DBH-ET(B);ET(B)(sl/sl) rats when the epithelial sodium channel is blocked with amiloride. We conclude that DBH-ET(B);ET(B)(sl/sl) rats are a novel single-locus genetic model of severe salt-sensitive hypertension. Our results suggest that DBH- ET(B);ET(B)(sl/sl) rats are hypertensive because they lack the normal tonic inhibition of the renal epithelial sodium channel.
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U2 - 10.1172/JCI8609
DO - 10.1172/JCI8609
M3 - Article
C2 - 10749572
AN - SCOPUS:0034093159
SN - 0021-9738
VL - 105
SP - 925
EP - 933
JO - Journal of Clinical Investigation
JF - Journal of Clinical Investigation
IS - 7
ER -