Your browser doesn't support javascript.
loading
Angiotensin II type 1 receptor is involved in flow-induced vasomotor responses of isolated middle cerebral arteries: role of oxidative stress.
Jukic, Ivana; Mihaljevic, Zrinka; Matic, Anita; Mihalj, Martina; Kozina, Natasa; Selthofer-Relatic, Kristina; Mihaljevic, Dubravka; Koller, Akos; Tartaro Bujak, Ivana; Drenjancevic, Ines.
Afiliación
  • Jukic I; Institute and Department of Physiology and Immunology, Faculty of Medicine Osijek, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia.
  • Mihaljevic Z; Scientific Centre of Excellence for Personalized Health Care, University of Josip Juraj Strossmayer University of Osijek, Osijek, Croatia.
  • Matic A; Institute and Department of Physiology and Immunology, Faculty of Medicine Osijek, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia.
  • Mihalj M; Scientific Centre of Excellence for Personalized Health Care, University of Josip Juraj Strossmayer University of Osijek, Osijek, Croatia.
  • Kozina N; Institute and Department of Physiology and Immunology, Faculty of Medicine Osijek, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia.
  • Selthofer-Relatic K; Scientific Centre of Excellence for Personalized Health Care, University of Josip Juraj Strossmayer University of Osijek, Osijek, Croatia.
  • Mihaljevic D; Institute and Department of Physiology and Immunology, Faculty of Medicine Osijek, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia.
  • Koller A; Scientific Centre of Excellence for Personalized Health Care, University of Josip Juraj Strossmayer University of Osijek, Osijek, Croatia.
  • Tartaro Bujak I; Department of Dermatology and Venereology, University Hospital Centre Osijek, Osijek, Croatia.
  • Drenjancevic I; Institute and Department of Physiology and Immunology, Faculty of Medicine Osijek, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia.
Am J Physiol Heart Circ Physiol ; 320(4): H1609-H1624, 2021 04 01.
Article en En | MEDLINE | ID: mdl-33666506
ABSTRACT
This study aimed to determine the mechanosensing role of angiotensin II type 1 receptor (AT1R) in flow-induced dilation (FID) and oxidative stress production in middle cerebral arteries (MCA) of Sprague-Dawley rats. Eleven-week old, healthy male Sprague-Dawley rats on a standard diet were given the AT1R blocker losartan (1 mg/mL) in drinking water (losartan group) or tap water (control group) ad libitum for 7 days. Blockade of AT1R attenuated FID and acetylcholine-induced dilation was compared with control group. Nitric oxide (NO) synthase inhibitor Nω-nitro-l-arginine methyl ester (l-NAME) and cyclooxygenase inhibitor indomethacin (Indo) significantly reduced FID in control group. The attenuated FID in losartan group was further reduced by Indo only at Δ100 mmHg, whereas l-NAME had no effect. In losartan group, Tempol (a superoxide scavenger) restored dilatation, whereas Tempol + l-NAME together significantly reduced FID compared with restored dilatation with Tempol alone. Direct fluorescence measurements of NO and reactive oxygen species (ROS) production in MCA, in no-flow conditions revealed significantly reduced vascular NO levels with AT1R blockade compared with control group, whereas in flow condition increased the NO and ROS production in losartan group and had no effect in the control group. In losartan group, Tempol decreased ROS production in both no-flow and flow conditions. AT1R blockade elicited increased serum concentrations of ANG II, 8-iso-PGF2α, and TBARS, and decreased antioxidant enzyme activity (SOD and CAT). These results suggest that in small isolated cerebral arteries 1) AT1 receptor maintains dilations in physiological conditions; 2) AT1R blockade leads to increased vascular and systemic oxidative stress, which underlies impaired FID.NEW & NOTEWORTHY The AT1R blockade impaired the endothelium-dependent, both flow- and acetylcholine-induced dilations of MCA by decreasing vascular NO production and increasing the level of vascular and systemic oxidative stress, whereas it mildly influenced the vascular wall inflammatory phenotype, but had no effect on the systemic inflammatory response. Our data provide functional and molecular evidence for an important role of AT1 receptor activation in physiological conditions, suggesting that AT1 receptors have multiple biological functions.
Asunto(s)
Palabras clave

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Vasodilatación / Endotelio Vascular / Circulación Cerebrovascular / Estrés Oxidativo / Arteria Cerebral Media / Mecanotransducción Celular / Receptor de Angiotensina Tipo 1 / Leucocitos Límite: Animals Idioma: En Revista: Am J Physiol Heart Circ Physiol Asunto de la revista: CARDIOLOGIA / FISIOLOGIA Año: 2021 Tipo del documento: Article País de afiliación: Croacia

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Vasodilatación / Endotelio Vascular / Circulación Cerebrovascular / Estrés Oxidativo / Arteria Cerebral Media / Mecanotransducción Celular / Receptor de Angiotensina Tipo 1 / Leucocitos Límite: Animals Idioma: En Revista: Am J Physiol Heart Circ Physiol Asunto de la revista: CARDIOLOGIA / FISIOLOGIA Año: 2021 Tipo del documento: Article País de afiliación: Croacia
...