Vascular endothelium is critically involved in the hypotensive and hypovolemic actions of atrial natriuretic peptide.
Atrial natriuretic peptide (ANP), via its vasodilating and diuretic effects, has an important physiological role in the maintenance of arterial blood pressure and volume. Its guanylyl cyclase-A (GC-A) receptor is highly expressed in vascular endothelium, but the functional relevance of this is controversial. To dissect the endothelium-mediated actions of ANP in vivo, we inactivated the GC-A gene selectively in endothelial cells by homologous loxP/Tie2-Cre-mediated recombination. Notably, despite full preservation of the direct vasodilating effects of ANP, mice with endothelium-restricted deletion of the GC-A gene (EC GC-A KO) exhibited significant arterial hypertension and cardiac hypertrophy. Echocardiographic and Doppler flow evaluations together with the Evan's blue dilution technique showed that the total plasma volume of EC GC-A KO mice was increased by 11-13%, even under conditions of normal dietary salt intake. Infusion of ANP caused immediate increases in hematocrit in control but not in EC GC-A KO mice, which indicated that ablation of endothelial GC-A completely prevented the acute contraction of intravascular volume produced by ANP. Furthermore, intravenous ANP acutely enhanced the rate of clearance of radio-iodinated albumin from the circulatory system in control but not in EC GC-A KO mice. We conclude that GC-A-mediated increases in endothelial permeability are critically involved in the hypovolemic, hypotensive actions of ANP.
Sabrane
Karim
K
Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany.
Kruse
Markus N
MN
Fabritz
Larissa
L
Zetsche
Bernd
B
Mitko
Danuta
D
Skryabin
Boris V
BV
Zwiener
Melanie
M
Baba
Hideo A
HA
Yanagisawa
Masashi
M
Kuhn
Michaela
M
D000818:Animals; D001158:Arteries / Q000378:metabolism / Q000473:pathology; D009320:Atrial Natriuretic Factor / Q000378:metabolism*; D002199:Capillary Permeability / Q000235:genetics; D006332:Cardiomegaly / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D004730:Endothelium, Vascular / Q000378:metabolism* / Q000473:pathology; D006162:Guanylate Cyclase / Q000235:genetics / Q000378:metabolism*; D006400:Hematocrit; D006801:Humans; D007022:Hypotension / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D020896:Hypovolemia / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D019426:Integrases / Q000235:genetics; D051379:Mice; D018345:Mice, Knockout; D032383:Myocytes, Cardiac / Q000378:metabolism / Q000473:pathology; D017461:Receptors, Atrial Natriuretic Factor / Q000235:genetics / Q000378:metabolism*; D014664:Vasodilation / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics
D014764:Viral Proteins; D009320:Atrial Natriuretic Factor; C045073:Cre recombinase; D019426:Integrases; D006162:Guanylate Cyclase; D017461:Receptors, Atrial Natriuretic Factor; C091715:atrial natriuretic factor receptor A