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Abstract

As differentiated from Wistar rats, myocardial ischemia and reperfusion produce no ventricular fibrillation in August rats. Pretreatment with nitric oxide synthase inhibitor Nw-nitro-L-arginine increased mortality rate in August rats with acute myocardial infarction from 20 to 40%. Under these conditions mortality rate in Wistar rats increased from 50 to 71%. Interstrain differences in the resistance of these animals to the arrhythmogenic effect of ischemia are probably associated with higher activity of the nitric oxide system in August rats compared to Wistar rats.

Heart resistance to oxidative stress in rats of different genetic strains

“…The weights of the heart and LV in August rats were higher than in Wistar rats by 14%. Our results are consistent with published data that August rats are more resistant to arrhythmia than Wistar rats [1]. Moreover, in August rats myocardial resistance to ischemia and reperfusion is higher than in Wistar rats.…”

“…Moreover, August rats are characterized by lower incidence and shorter duration of severe arrhythmias during acute ischemia and reperfusion compared to Wistar rats [1]. Activation of free radical processes plays a major role in the pathogenesis of ischemic and reperfusion injury.…”

Peculiarities of autonomic regulation assessed by variability of hemodynamic parameters in rats with different stress resistance

“…Probably, enhanced resistance of August rats to stress-induced ulceration is primarily related to moderated activity of PNS, which plays an important role in this pathology. In addition, August rats demonstrate enhanced resistance to ischemia, which can be related to increased activity of the NO system known to protect the heart against ischemic damages [2]. Thus, the pathogenetic role of HR and BP oscillations is different in various genetic strains of the same animals.…”

“…August rats are less resistant to long-term immobilization stress due to dramatic drop in BP [8], but more resistant to stress-induced ulceration of the gastric mucosa [6] compared to Wistar rats. Moreover, August rats demonstrate lower mortality during acute myocardial infarction and lower incidence of severe arrhythmias than Wistar rats [2]. An important role in the pathogenesis of these diseases is played by activation of sympathetic nervous system (SNS).…”

Adaptation of the cardiovascular system to postinfarction cardiosclerosis in rats with congenital adrenoreactivity of the myocardium

“…Published data show that the mortality rate and incidence of arrhythmias and contractile dysfunction caused by acute myocardial infarction in August rats are much lower than in Wistar rats [1,3,9]. Stress-induced activation of the sympathoadrenal system (SAS) plays an important role in the pathogenesis of ischemic damage to the myocardium.…”