Stress triggers different pathophysiological mechanisms in younger and older cardiomyopathic hamsters
Stress triggers different pathophysiological mechanisms in younger and older cardiomyopathic hamsters
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DOI：
10.1016/s0008-6363(95)00165-4
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发表时间：
1995-12-01
影响因子：
10.8
通讯作者：
Conway, RS
中科院分区：
文献类型：
--
作者：
Chang, Q;Natelson, BH;Conway, RS
目的：由于心肌病仓鼠（CMH）在其疾病的病变形成期比老年CMH更容易受到应激的致命影响，我们测试了这一假设，即不同的病理生理学影响的压力可能会发生：冠状动脉血管痉挛在年轻的CMH和充血性心力衰竭在老年人。方法：2.5月龄和6.5月龄CMH采用仰卧位冷制动2 h，连续5d。在应激后3、5和7天，切除心脏并使用改良的Langendorff系统进行灌注。记录最大+/-dP/dt、发展压、心室舒张时间（Tau）和冠状动脉血管阻力（CVR），并在冠状动脉内灌注精氨酸加压素（AVP）后测定CVR。结果如下：在老年CMH中，应激导致心室功能障碍（最大+/-dP/dt降低，压力增加，Tau增加）（P < 0.05），但在年轻CMH中则没有。年轻CMH的基线CVR显著高于老年CMH（P < 0.01），AVP输注使年轻应激CMH的CVR增加幅度大于年轻非应激CMH或老年应激CMH（P < 0.05）。结论：年轻的CMH心脏表现出更大的静息血管张力，压力产生冠状动脉血管收缩，这与冠状动脉痉挛一致。相比之下，老年CMH经历了心脏功能的下降，其在应激后保持7天，并且表明CHF从应激前存在的轻度形式加重。应激的致死效应可能是由于在年轻和老年CMH中激活了不同的病理过程。
Objectives: Because cardiomyopathic hamsters (CMHs) in the lesion-forming period of their disease are more susceptible to the lethal effects of stress than older CMHs, we tested the hypothesis that different pathophysiological effects of stress may occur: coronary vasospasm in younger CMHs and congestive heart failure in older ones. Methods: CMHs aged 2.5 and 6.5 months were stressed with 2 h supine cold immobilization for 5 consecutive days. Three, 5 and 7 days after stress, the hearts were excised and perfused using a modified Langendorff system. Maximum +/-dP/dt, developed pressure, ventricular relaxation time (Tau) and coronary vascular resistance (CVR) were recorded and CVR was also measured following coronary infusion of arginine vasopressin (AVP). Results: Stress produced ventricular dysfunction (decreased maximum +/-dP/dt, developed pressure, and increased Tau) in older CMHs (P < 0.05) but not in younger CMHs. Baseline CVR in younger CMHs was significantly higher than in older CMHs(P < 0.01) and AVP infusion produced a bigger increase in CVR in younger stressed CMHs than in either younger nonstressed or older stressed CMHs (P < 0.05). Conclusion: The younger CMH heart exhibits greater resting vascular tone and stress produces coronary vasoconstriction that is consistent with coronary spasm. In contrast, the older CMH experiences a decrease in cardiac function which remains 7 days after stress and indicates an exacerbation of CHF from the mild form existing prior to stress. The lethal effects of stress may occur because of the activation of different pathological processes in younger and older CMHs.