烧伤血浆毒性物质对豚鼠心肌线粒体功能的影响

本文采用豚鼠背部皮肤烧伤(35％TBSAⅢ度)模型,观察了豚鼠烧伤后8小时血浆毒性物质(BPS)对正常心肌线粒体的呼吸控制率、Ca~(2+)—ATP酶、Na~+/K~+—ATP酶活性及Mg~(2+)—ATP酶活性,脂质过氧化物(LPO)含量,超氧化物歧化酶(SOD)活性及维生素E(Vit.E)含量的影响,并与豚鼠烧伤后8小时心肌线粒体上述功能指标的变化相比较。结果发现,烧伤血浆毒性物质使心肌线粒体(1)呼吸控制率下降。且与BPS的作用浓度有明显依赖性;(2)Na~+/K~+—ATP酶及Ca~(2+)—ATP酶活性降低;(3)LPO含量升高、SOD活性降低及Vit,E含量降低,上述变化与烧伤后8小时心肌线粒体的变化一致。 上述结果提示:烧伤血浆毒性物质的作用可能是严重烧伤早期心脏功能抑制的重要原因之一,其作用可能与其抑制线粒体的呼吸功能有关,ATP酶活性降低又进一步影响线粒体的物质转运、膜内外的离子平衡、能量代谢及心肌细胞的电活动。同时,烧伤血浆毒性物质对心功能的抑制过程中有氧自由基反应参与。

Effect of Burned Piasmic Substances on the Functions ofMyoeardial Mitochondria in Guivea Pigs

The effects of hte burned plasmic substance (BPS) on the respiratory control rate (RCR).Na/K -ATPase,Ca- ATPase and Mg - ATPase activities, lipid peroxides (LPO) level.superoxide dismutase, (SOD) activity as well as the vitamin E content of normal myocardial mitochondria were investigated in this article. The BPS was extraced from the blood plasma of guinea pigs after burn injury (35% TBSA full thickness burn). The effects of burn injury on these parameter as mentioned above were alos noted for comparison with those of BPS.The results showed that: as compared with normal control.the BPS caused that:(1) RCR was decreased and it depended on the concentration of the BPS: (2) The activity of Na/K-ATPase and Ca-ATPase were decreased; (3) The LPO content was increased,the activity of SOD and the content of Vit. E were reduced; (4) Changes of the functional parameters of myocardial mitochondria caused by burn injury were the same as those of BPSi (5)The effects of NPS were similar to that of BPS,but lessec than the later.These results suggest that the inhibitory effects of BPS on the cardiac functions are probably caused by inhibiting respiratory function of myocardial mitochondria. Further more,the deoreses of the ATPase activity influence material transport, fome equilibrium across membrane, energy metablism, as well as electrical activity of myocardiai cells.On the other hand,the free radical reaction was participated in the inhibitory process of cardiac functions induced by BPS. It indicates that the toxic action of BPS may play a role in the decline of cardiac function early after burn injury. The components of BPS may include some contents of normal blood plasma.