| Chronic exposure to carbon disulfide (CS2) can cause coronary heart disease, hypertension and other cardiovascular diseases, which has been demonstrated by many epidemiological investigations and experimental researches. However, the mechanisms of its cardiovascular toxicity still remain unclear. In 90s', there were reported that lipid peroxidation(LPO) might play an important role on it , but the details are not clear yet.The aim of this study is to observe the changes of the levels of malonyldialdehyde (MDA), nitric Oxide (NO) and the activity of superoxide dismutase (SOD) in plasma. In addition, morphological changes of aortas are examined under light microscope, and aortas, myocardium, hepar and cerebral cortex were examined by transmission electron microscope to explore: 1. The influence of CSa on the levels of MDA, NO and SOD, 2. The ultrastracture changes of aortas, cardiac muscle, hepar and cerebral cortex in exposed groups. The relationship of all this changes mentioned above and lipid peroxidation were discussed to reveal thepossible toxic mechanisms of arteriosclerosis (AS) induced by €82.Thirty healthy adult Sprague-Dawley (170-25 2g) male rats were assigned randomly into 3 groups. Two groups were given different doses of CSj (320mg/kg, 160mg/kg in olive oil intra peritoneal). Control group was given physiological saline only.l time/day, 6 days/week over 7 weeks. Blood samples were collected for measurement of NO, LPO in plasma and erythrocyte SOD activity. In addition, morphological changes of aortas in two CS2 exposed groups were examined under an optical microscope. Sections of aortas, cardiac muscle, cerebral cortex and hepar in exposed groups were examined under a transmission electron microscope. Statistical package for the social sciences (SPSS 10.0) for windows was used for data analysis, statistical method included analysis of variance, analysis of correlation and analysis of multiple regression.The results showed: l.The mean values of MDA in control, 160 mg/kg and 320mg/kg groups were 3.05 nmol/L, 4.30 nmol/L and 5.40 nmol/L, respectively. And that of median values of SOD were 364.61 Nu/ml, 392.05 Nu/ml and 351.71Nu/ml. And the median values of NO were 19.8 umol/L, 24.26 umol/L and 36.63 umol/L, respectively. The levels of MDA showed a tendency to increase (p<0.05), the values in 320mg/kg group and 160mg/kg were higher than that in controls group (p<0.05). The levels of NO and the activity of SOD had no significantly change. 2. The levels of MDA revealed a significant positive correlation with the dose of CS2 (r =0.882, ^=0.000). 3. No obviously histomorphological changes were found in aortas of exposed groups under the optical microscope. 4. The endothelial cells of aortic arch were swelling, the nuclei of which was twisted, a part of chromatin was dissolved and migrated to the cell edge. The smooth muscle cells of aortic arch were transferred into sub endothelial layer and the nuclei of which was twisted, too. All these changes may be induced by lipid peroxidation, which may be the mechanismsof carbon disulfide's cardiovascular toxicity. Damages in cardiac muscle cells of mitochondria were of inflated significantly. The crista on the inner membrane of mitochondria were disappeared or decreased, accompanied with lipid droplets. The nuclei of cardiac muscles became twisted. The nuclei in hepatic cells of rat exposed to CS2 was karyopyknotic and deformed, the nuclear membrane was umbilicated and the edge was blurry. The cytoplasm contains vesicles of various size accompanied by massive development of smooth endoplasmic reticulum. Dense eosinophilic masses in the hepatic cytoplasm. The nuclei of cerebral cortex cell became twisted, the nuclear membrane was unclear, and the ridge in the inner membrane of mitochondria was disappeared or unclear, accompanied with lipid droplets. All these changes mentioned above coincide in the early morphological changes of AS and may be related to the injury of lipid peroxidation induced by CS2The results mentioned above indicate: 1 : the... |
