BACKGROUND: Oxidative stress is a key mediator in the maintenance of sympathoexcitation and hypertension in human and experimental models. Green tea is widely known to be potent antioxidant. OBJECTIVE: We aimed to evaluate the effects of green tea in a model of hypertension. METHODS: Hypertension was induced by the nitric oxide synthase inhibitor [N-nitro-L-arginine-methyl-ester (L-NAME); 20 mg/kg per day, orally, for 2 weeks] in male Wistar rats. After the first week of L-NAME treatment, animals received green tea ad libitum for 1 week. At the end of the treatment period, blood pressure, heart rate, baroreflex sensitivity, renal sympathetic nerve activity, and vascular and systemic oxidative stress were assessed. RESULTS: L-NAME-treated animals exhibited an increase in blood pressure (165 ± 2 mmHg) compared with control rats (103 ± 1 mmHg) and green tea treatment reduced hypertension (119 ± 1 mmHg). Hypertensive animals showed a higher renal sympathetic nerve activity (161 ± 12 spikes/s) than the control group (97 ± 2 spikes/s), and green tea also decreased this parameter in the hypertensive treated group (125 ± 5 spikes/s). Arterial baroreceptor function and vascular and systemic oxidative stress were improved in hypertensive rats after green tea treatment. CONCLUSIONS: Taken together, short-term green tea treatment improved cardiovascular function in a hypertension model characterized by sympathoexcitation, which may be because of its antioxidant properties.
BACKGROUND: Oxidative stress is a key mediator in the maintenance of sympathoexcitation and hypertension in human and experimental models. Green tea is widely known to be potent antioxidant. OBJECTIVE: We aimed to evaluate the effects of green tea in a model of hypertension. METHODS:Hypertension was induced by the nitric oxide synthase inhibitor [N-nitro-L-arginine-methyl-ester (L-NAME); 20 mg/kg per day, orally, for 2 weeks] in male Wistar rats. After the first week of L-NAME treatment, animals received green tea ad libitum for 1 week. At the end of the treatment period, blood pressure, heart rate, baroreflex sensitivity, renal sympathetic nerve activity, and vascular and systemic oxidative stress were assessed. RESULTS:L-NAME-treated animals exhibited an increase in blood pressure (165 ± 2 mmHg) compared with control rats (103 ± 1 mmHg) and green tea treatment reduced hypertension (119 ± 1 mmHg). Hypertensive animals showed a higher renal sympathetic nerve activity (161 ± 12 spikes/s) than the control group (97 ± 2 spikes/s), and green tea also decreased this parameter in the hypertensive treated group (125 ± 5 spikes/s). Arterial baroreceptor function and vascular and systemic oxidative stress were improved in hypertensiverats after green tea treatment. CONCLUSIONS: Taken together, short-term green tea treatment improved cardiovascular function in a hypertension model characterized by sympathoexcitation, which may be because of its antioxidant properties.
Authors: Erika E Nishi; Vitor R Almeida; Fernanda G Amaral; Karin A Simon; Henrique A Futuro-Neto; Roberto B Pontes; Juliana G Cespedes; Ruy R Campos; Cássia T Bergamaschi Journal: Hypertens Res Date: 2019-07-17 Impact factor: 3.872
Authors: Alynne Carvalho-Galvão; Danilo D A Gadelha; José L de Brito Alves; Barkat A Khan; Raul J H Castro-Gomez; Josiane C Cruz; Marciane Magnani; Valdir A Braga Journal: Front Physiol Date: 2018-05-23 Impact factor: 4.566
Authors: Lysien I Zambrano; Roberto B Pontes; Michelle L Garcia; Erika E Nishi; Fernando N Nogueira; Elisa M S Higa; Juliana G Cespedes; Cassia T Bergamaschi; Ruy R Campos Journal: Physiol Rep Date: 2019-07