Angiotensin Converting Enzyme Inhibition Reduces Cardiovascular Responses to Acute Stress in Myocardially Infarcted and Chronically Stressed Rats

Abstract

Previous studies showed that chronically stressed and myocardially infarcted rats respond with exaggerated cardiovascular responses to acute stress. The present experiments were designed to elucidate whether this effect can be abolished by treatment with the angiotensin converting enzyme (ACE) inhibitor captopril. Sprague Dawley rats were subjected either to sham surgery (Groups 1 and 2) or to myocardial infarction (Groups 3 and 4). The rats of Groups 2 and 4 were also exposed to mild chronic stressing. Four weeks after the operation, mean arterial blood pressure (MABP) and heart rate (HR) were measured under resting conditions and after application of acute stress. The cardiovascular responses to the acute stress were determined again 24 h after administration of captopril orally. Captopril significantly reduced resting MABP in each group. Before administration of captopril, the maximum increases in MABP evoked by the acute stressor in all (infarcted and sham-operated) chronically stressed rats and also in the infarcted nonchronically stressed rats were significantly greater than in the sham-operated rats not exposed to chronic stressing. These differences were abolished by captopril. The results suggest that ACE may improve tolerance of acute stress in heart failure and during chronic stressing.

Emotional Stress and Cardiovascular Complications in Animal Models: A Review of the Influence of Stress Type

“…Based on this, Nalivaiko ( 2011 ) proposed that the identification of hypertensive effect preferentially by the tail-cuff method would be due to a more vigorous reaction of the animals stressed to the tail-cuff procedure. Hence, it has been reported that exposure to chronic stressors increases pressor response during acute aversive stimuli (Grippo et al, 2002 , 2006 ; Cudnoch-Jedrzejewska et al, 2010 , 2014 ; Maslova et al, 2010 ).…”

Cardiovascular Reactivity to a Novel Stressor: Differences on Susceptible and Resilient Rats to Social Defeat Stress

“…Exaggerated pressure response to acute stress challenge has been described in the literature in the animal models of depression (Grippo et al, 2002(Grippo et al, , 2010Nalivaiko, 2011;Cudnoch-Jedrzejewska et al, 2014;McNeal et al, 2014;Benini et al, 2020) but not consistently. In men, social discrimination was related to increased cardiovascular reactivity during a stress session (Richman et al, 2007), while a positive emotional style accelerated the cardiovascular recovery after an acute stressor (Bostock et al, 2011).…”

Envolvimento do sistema renina-angiotensina na modulação das respostas autonômicas, neuroendócrina e funcionais ocasionadas pela exposição aguda ao estresse de restrição em ratos

“…Adicionalmente, ratos previamente estressados de maneira crônica e posteriormente tratados com captopril, apresentaram uma redução da resposta pressora máxima ocasionada por uma nova exposição ao air-jet stress, além disso, em ratos infartados cirurgicamente, o tratamento com captopril foi capaz de reduzir a resposta taquicárdica máxima ocasionada pelo air-jet stress, tanto no grupo previamente estressado de maneira crônica, quando no grupo nãoestressado (CUDNOCH-JEDRZEJEWSKA et al, 2014). Em conjunto, esses resultados sugerem que a inibição da ECA, e consequente diminuição da formação de Ang-II, pode ser importante na prevenção de alterações cardiovasculares desencadeadas por modelos de estresse.…”