A study on cardiac injury of methamphetamine abusers

目的：探讨长期给药机械胺（MA）对动物的影响。马5。10. 注射20 mg/kg b.w.，每周6次，连续注射2、4周。在显微镜下观察发现：肥大。萎缩。嗜酸性粒细胞改变、空泡化、收缩带坏死和肌纤维紊乱。最小斑片状纤维化。间质水肿及小圆细胞浸润。除三角区肌纤维紊乱外，这些病变主要见于左心室和隔膜。电镜进一步显示肉瘤不规则，肌节过度收缩，肌带增厚。肌原纤维成分和线粒体增加，肌质网扩张。肌原纤维消失。有时可见线粒体变性和肌纤维紊乱。此外。有时可在肌膜上观察到许多单膜囊泡。更多的面小泡大小与扩张的肌浆网相似，有时与肉瘤融合，可见于基底膜。内皮细胞和毛细血管管中。一般来说，这些心脏病变的严重程度与给予MA的剂量和持续时间成正比。而小剂量MA组肌纤维紊乱较多。然后，我们比较了MA与儿茶酚胺治疗后的病变。并检测了-阻滞剂和钙拮抗剂的作用。去甲肾上腺素给药后的心脏病变与MA给药后相似，但程度有限。在控制上。预用药普萘洛尔和维拉帕米可防止心脏病变的出现。焦磷酸gei细胞电泳给药小鼠心肌肌球蛋白的形态与对照组有显著差异。因此。MA滥用者的各种心脏病变似乎可以用MA本身的心脏毒性来解释。Furtheermore。我们的结果表明。MA通过神经末梢释放儿茶酚胺诱导心脏损伤。也可能是钙的过量。少

To investigate the effects of long-term mechamphetaminc(MA) administration in animals. MA 5. 10. 20 mg/kg b.w. was injected to ddy male mice 6 times per week for 2 or 4 weeks. In microscopic observations there were the findings: hypertrophy. atrophy. eosinophilic changes, vacuolation contraction band nccrosis and disarray of myofibers. minimum patchy fibrosis. interstitial edema and infiltrations of small round cells. These lesions were mainly seen at the left ventricle and the septum except disarray of myotibers which was prominent at the triangle region. Electorn microscopy revealed further appearance of irregularity of sarcolomma, hypercontraction of sarcomere, thickning of % band. increase in myofibrillar elements and mitochondria and dilatation of the sarcomplasmic reticuliums. Dissapearance of myofibrils. degenerations of mitochondia and myofibrillar disarray were sometimes seen. Furthermore. many single membrane vesicles were sometimes observed bancath the sarcolemma. Thesed sur … More face vesiclees were similar to dilated sarcoplasmic reticulums in size, sometimes fused with sarcolomma and seen in the basement membrane. inthe cndothelial cells and in the capillary lumen. In general, the severity of these cardiac lesions were in proportion to both the doso and the duration of MA administrated. but disarray of myofibers were rather found frequently in the group administered smaller dose of MA. We then compared the lesions by MA with those after administration of catecholamine. and also examined the effect of -blocker and Ca-antagonist. The cardiac lesions after norepincphrine administration were similar to those after MA administration but to a limited extent. On the contrally. premedication of propranolol and verapamil prevented the appcarance of the cardiac lesion. isolorm pattern of cardiac myosin of the mice administered MA as by pyrophosphate gei cicotrophoresis showed to so remarkable difference from that of controll mice. Thus. various cardiac lesions found in MA abusers seemed to be explained by the cardiac toxicity of MA by itself. Furtheermore. our result suggests that. MA induces cardiac injury through catecholamine released from nerve endings. and possibly caleium everioad may be also involved. Less