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Altered cardiovascular reflexes responses in conscious angiotensin-(1-7) receptor Mas knockout mice

Item Type:Article
Title:Altered cardiovascular reflexes responses in conscious angiotensin-(1-7) receptor Mas knockout mice
Creators Name:Moura, M.M., Souza dos Santos, R.A., Campagnole-Santos, M.J., Todiras, M., Bader, M., Alenina, N. and Haibara, A.S.
Abstract:This study evaluated the physiological importance of Angiotensin-(1-7) receptor Mas on reflex control of circulation. Experiments were performed in male Mas-knockout (Mas-KO) and Wild Type (WT) conscious mice (12-20 wk of age). Baroreceptor reflex was evaluated by the bradycardic response induced by phenylephrine (0.25mug/5mul, i.v.). Bezold-Jarisch reflex was evaluated by phenylbiguanide (0.5mug/5mul, i.v.) and chemoreflex by potassium cyanide (2.5mug/5mul, i.v.). Baseline mean arterial pressure was higher in Mas-KO (n=14) as compared with WT mice (n=18) (118+/-1 vs. 109+/-2 mmHg); however, heart rate was similar in both strains (615+/-30 vs. 648+/-13 bpm). Baroreflex bradycardia was lower (0.78+/-0.44 vs. 1.30+/-0.14ms/mmHg) in Mas-KO compared with WT mice. The depressor (-17+/-5 vs. -45+/-6 mmHg) and bradycardic (-212+/-36 vs. -391+/-29 bpm) components of the Bezold-Jarisch reflex were also lower in Mas-KO mice. In addition, chemoreflex pressor response (+20+/-3 vs. +12+/-0.8 mmHg) and bradycardic response (-250+/-74 vs. -52+/-26 bpm) were significantly higher in Mas-KO. These results further advances previous studies by showing that the lack of Mas receptor induced important imbalance in the neural control of blood pressure, altering not only the baroreflex but also the chemo- and Bezold Jarisch reflexes.
Keywords:Angiotensin-(1-7) Receptor Mas, Conscious Mice, Blood Pressure Control, Cardiovascular Reflexes, Animals, Mice
Page Range:1934-1939
Date:October 2010
Official Publication:https://doi.org/10.1016/j.peptides.2010.06.030
PubMed:View item in PubMed

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