Hypertension in mice with transgenic activation of the brain renin-angiotensin system is vasopressin dependent.

American journal of physiology. Regulatory, integrative and comparative physiology (2013-03-29)
Nicole K Littlejohn, Rick B Siel, Pimonrat Ketsawatsomkron, Christopher J Pelham, Nicole A Pearson, Aline M Hilzendeger, Beth A Buehrer, Benjamin J Weidemann, Huiping Li, Deborah R Davis, Anthony P Thompson, Xuebo Liu, Martin D Cassell, Curt D Sigmund, Justin L Grobe
RESUMEN

An indispensable role for the brain renin-angiotensin system (RAS) has been documented in most experimental animal models of hypertension. To identify the specific efferent pathway activated by the brain RAS that mediates hypertension, we examined the hypothesis that elevated arginine vasopressin (AVP) release is necessary for hypertension in a double-transgenic model of brain-specific RAS hyperactivity (the "sRA" mouse model). sRA mice experience elevated brain RAS activity due to human angiotensinogen expression plus neuron-specific human renin expression. Total daily loss of the 4-kDa AVP prosegment (copeptin) into urine was grossly elevated (≥8-fold). Immunohistochemical staining for AVP was increased in the supraoptic nucleus of sRA mice (~2-fold), but no quantitative difference in the paraventricular nucleus was observed. Chronic subcutaneous infusion of a nonselective AVP receptor antagonist conivaptan (YM-087, Vaprisol, 22 ng/h) or the V(2)-selective antagonist tolvaptan (OPC-41061, 22 ng/h) resulted in normalization of the baseline (~15 mmHg) hypertension in sRA mice. Abdominal aortas and second-order mesenteric arteries displayed AVP-specific desensitization, with minor or no changes in responses to phenylephrine and endothelin-1. Mesenteric arteries exhibited substantial reductions in V(1A) receptor mRNA, but no significant changes in V(2) receptor expression in kidney were observed. Chronic tolvaptan infusion also normalized the (5 mmol/l) hyponatremia of sRA mice. Together, these data support a major role for vasopressin in the hypertension of mice with brain-specific hyperactivity of the RAS and suggest a primary role of V(2) receptors.

MATERIALES
Referencia del producto
Marca
Descripción del producto

Sigma-Aldrich
Tolvaptan, ≥98% (HPLC), powder

Redes sociales

LinkedIn icon
Twitter icon
Facebook Icon
Instagram Icon

Merck

Investigación. Desarrollo. Producción.

Somos un proveedor líder para la industria de Ciencias de la Vida con soluciones y servicios para investigación, desarrollo y producción biotecnológicos, y para desarrollo y producción de tratamientos farmacéuticos

© 2021 Merck KGaA, Darmstadt, Alemania y/o sus filiales. Todos los derechos reservados.

Queda estrictamente prohibida la reproducción sin permiso de cualquiera de los materiales de la página web.