TY - JOUR
T1 - The role of AT1-receptor blockade on reactive oxygen species and cardiac autonomic drive in experimental hyperthyroidism
AU - Baraldi, D.
AU - Casali, K.
AU - Fernandes, R. O.
AU - Campos, C.
AU - Sartório, C.
AU - Conzatti, A.
AU - Couto, G. K.
AU - Schenkel, P. C.
AU - Belló-Klein, A.
AU - Araujo, A. R.S.
PY - 2013/10
Y1 - 2013/10
N2 - The objective of this study was to explore the influence of the renin-angiotensin system on cardiac prooxidants and antioxidants levels and its association to autonomic imbalance induced by hyperthyroidism. Male Wistar rats were divided into four groups: control, losartan (10mg/kg/day by gavage, 28day), thyroxine (T4) (12mg/L in drinking water for 28days), and T4+losartan. Spectral analysis (autonomic balance), angiotensin II receptor (AT1R), NADPH oxidase, Nrf2 and heme-oxygenase-1 (HO-1) myocardial protein expression, and hydrogen peroxide (H2O2) concentration were quantified. Autonomic imbalance induced by hyperthyroidism (~770%) was attenuated in the T4+losartan group (~32%) (P<0.05). AT1R, NADPH oxidase, H2O2, as well as concentration, Nrf2 and HO-1 protein expression were elevated (~172%, 43%, 40%, 133%, and 154%, respectively) in T4 group (P<0.05). H2O2 and HO-1 levels were returned to control values in the T4+losartan group (P<0.05). The overall results demonstrate a positive impact of RAS blockade in the autonomic control of heart rate, which was associated with an attenuation of H2O2 levels, as well as with a reduced counter-regulatory response of HO-1 in experimental hyperthyroidism.
AB - The objective of this study was to explore the influence of the renin-angiotensin system on cardiac prooxidants and antioxidants levels and its association to autonomic imbalance induced by hyperthyroidism. Male Wistar rats were divided into four groups: control, losartan (10mg/kg/day by gavage, 28day), thyroxine (T4) (12mg/L in drinking water for 28days), and T4+losartan. Spectral analysis (autonomic balance), angiotensin II receptor (AT1R), NADPH oxidase, Nrf2 and heme-oxygenase-1 (HO-1) myocardial protein expression, and hydrogen peroxide (H2O2) concentration were quantified. Autonomic imbalance induced by hyperthyroidism (~770%) was attenuated in the T4+losartan group (~32%) (P<0.05). AT1R, NADPH oxidase, H2O2, as well as concentration, Nrf2 and HO-1 protein expression were elevated (~172%, 43%, 40%, 133%, and 154%, respectively) in T4 group (P<0.05). H2O2 and HO-1 levels were returned to control values in the T4+losartan group (P<0.05). The overall results demonstrate a positive impact of RAS blockade in the autonomic control of heart rate, which was associated with an attenuation of H2O2 levels, as well as with a reduced counter-regulatory response of HO-1 in experimental hyperthyroidism.
KW - Autonomic balance
KW - Heme-oxygenase-1
KW - Hydrogen peroxide
KW - Hyperthyroidism
KW - Nrf2
KW - ROS
UR - https://www.scopus.com/pages/publications/84883783135
U2 - 10.1016/j.autneu.2013.04.003
DO - 10.1016/j.autneu.2013.04.003
M3 - Article
C2 - 23623788
AN - SCOPUS:84883783135
SN - 1566-0702
VL - 177
SP - 163
EP - 169
JO - Autonomic Neuroscience: Basic and Clinical
JF - Autonomic Neuroscience: Basic and Clinical
IS - 2
ER -