BACKGROUND: The literature describes contradictory data regarding the onset of the baroreflex reduction in spontaneously hypertensive rats. OBJECTIVE: This investigation was undertaken to evaluate the baroreflex function in 13-week-old spontaneously hypertensive rats. METHODS: Male Wistar Kyoto (n=15) and spontaneously hypertensive rats (n=15) aged 13 weeks were studied. Cannulas were inserted in the abdominal aortic artery through the right femoral artery to measure mean arterial pressure and heart rate. Baroreflex function was calculated as the derivative of the variation of HR in function of the MAP variation (Delta heart rate/Delta mean arterial pressure) tested with a depressor dose of sodium nitroprusside (50microg/kg) and with a pressor dose of phenylephrine (8microg/kg) in the right femoral venous approach through an inserted cannula in awake spontaneously hypertensive rats and Wistar-Kyoto. Differences with p values < 0.05 were considered statistically significant. RESULTS: Spontaneously hypertensive rats: Delta mean arterial pressure=43.5mmHg+/-5.2, Delta heart rate=-59.7ppm+/-17.9 and Delta heart rate/Delta mean arterial pressure=1.3ppm/mmHg+/-0.1 tested with phenylephrine; Wistar Kyoto: Delta mean arterial pressure=&56mmHg+/-3, Delta heart rate=*-114.9ppm+/-11.3 and Deltaheart rate/Delta mean arterial pressure=#1.9ppm/mmHg+/-0.3 tested with phenylephrine; spontaneously hypertensive rats: Delta mean arterial pressure=-45.6mmHg+/-8.1, Delta heart rate=40.1ppm+/-11.6 and Delta heart rate/Delta mean arterial pressure=0.9ppm/mmHg+/-0.5 tested with sodium nitroprusside; Wistar Kyoto: Delta mean arterial pressure=-39.8mmHg+/-6.2, Delta heart rate=51.9ppm+/-21.8 and Delta heart rate/Delta mean arterial pressure=1.4ppm/mmHg+/-0.7 tested with sodium nitroprusside (*p<0.05; #p<0.01; &<0.001). CONCLUSION: Our results showed that 13-week-old spontaneously hypertensive rats presented reduced baroreflex function when tested with phenylephrine.
BACKGROUND: The literature describes contradictory data regarding the onset of the baroreflex reduction in spontaneously hypertensiverats. OBJECTIVE: This investigation was undertaken to evaluate the baroreflex function in 13-week-old spontaneously hypertensiverats. METHODS: Male Wistar Kyoto (n=15) and spontaneously hypertensiverats (n=15) aged 13 weeks were studied. Cannulas were inserted in the abdominal aortic artery through the right femoral artery to measure mean arterial pressure and heart rate. Baroreflex function was calculated as the derivative of the variation of HR in function of the MAP variation (Delta heart rate/Delta mean arterial pressure) tested with a depressor dose of sodium nitroprusside (50microg/kg) and with a pressor dose of phenylephrine (8microg/kg) in the right femoral venous approach through an inserted cannula in awake spontaneously hypertensiverats and Wistar-Kyoto. Differences with p values < 0.05 were considered statistically significant. RESULTS: Spontaneously hypertensiverats: Delta mean arterial pressure=43.5mmHg+/-5.2, Delta heart rate=-59.7ppm+/-17.9 and Delta heart rate/Delta mean arterial pressure=1.3ppm/mmHg+/-0.1 tested with phenylephrine; Wistar Kyoto: Delta mean arterial pressure=&56mmHg+/-3, Delta heart rate=*-114.9ppm+/-11.3 and Deltaheart rate/Delta mean arterial pressure=#1.9ppm/mmHg+/-0.3 tested with phenylephrine; spontaneously hypertensiverats: Delta mean arterial pressure=-45.6mmHg+/-8.1, Delta heart rate=40.1ppm+/-11.6 and Delta heart rate/Delta mean arterial pressure=0.9ppm/mmHg+/-0.5 tested with sodium nitroprusside; Wistar Kyoto: Delta mean arterial pressure=-39.8mmHg+/-6.2, Delta heart rate=51.9ppm+/-21.8 and Delta heart rate/Delta mean arterial pressure=1.4ppm/mmHg+/-0.7 tested with sodium nitroprusside (*p<0.05; #p<0.01; &<0.001). CONCLUSION: Our results showed that 13-week-old spontaneously hypertensiverats presented reduced baroreflex function when tested with phenylephrine.
Authors: José R Cisternas; Vitor E Valenti; Thales B Alves; Celso Ferreira; Márcio Petenusso; João R Breda; Adilson C Pires; Nadir Tassi; Luiz Carlos de Abreu Journal: Int Arch Med Date: 2010-01-27
Authors: Vitor E Valenti; Luiz Carlos de Abreu; Fernando L A Fonseca; Jose-Luiz Figueiredo; Fernando Adami; Celso Ferreira Journal: Int J Health Sci (Qassim) Date: 2013-06
Authors: Vitor E Valenti; Luiz Carlos de Abreu; Monica A Sato; Celso Ferreira; Fernando Adami; Fernando L A Fonseca; Valdelias Xavier; Moacir Godoy; Carlos B Monteiro; Luiz Carlos M Vanderlei; Paulo H N Saldiva Journal: BMC Cardiovasc Disord Date: 2012-03-30 Impact factor: 2.298
Authors: Vitor E Valenti; Luiz Carlos M Vanderlei; Celso Ferreira; Fernando L A Fonseca; Fernando R Oliveira; Fernando H Sousa; Luciano M Rodrigues; Carlos B M Monteiro; Fernando Adami; Rubens Wajnsztejn; Luiz Carlos de Abreu Journal: Int Arch Med Date: 2013-03-07
Authors: Vitor E Valenti; Luiz Carlos de Abreu; Fernando L A Fonseca; Fernando Adami; Monica A Sato; Luiz Carlos M Vanderlei; Lucas Lima Ferreira; Luciano M Rodrigues; Celso Ferreira Journal: Clinics (Sao Paulo) Date: 2013-06 Impact factor: 2.365