Gevorgian E G, Pogosian E G, Miridzhanian M I, Oganesian N M, Hirsch E
Radiats Biol Radioecol. 2009 Nov-Dec;49(6):681-7.
The peculiarities of the functional status of autonomic nervous system and physical efficiency were studied in white inbred rats under dynamics of combined radiation/thermal injury (CR/TI). The CR/TI model was obtained under total X-ray irradiation at dose level of 4.37 Gy and inflicting III degree burn injury making 12% of body surface in 24 rats. The studies were performed under conditions of both spontaneous CR/TI development and protecting the burn wound against infection. In 12 rats the wounds were covered by polymer films treated with iodine and succinic acid. On days 3, 7, 14, 21 and 28 of CR/TI, as well as prior to CR/TI (datum level), heart rate variability (HRV) indices, the level of physical efficiency (the retention time of own weight on the vertical pole), indices of body mass, survival, and average life-soan of animals were recorded. For registration of ECG in awake rats, corrections of motor artifacts and analysis of HRV the original software program was used. R-R intervalograms were analyzed in time and frequency domains. The sliding window technique was used (100 R-R intervals with the step of 10 seconds; epoch of analysis--7 minutes). The obtained data indicated that the survival level and the average life-span in rats with the film-covered burn wound were higher as compared to the "pure" CR/TI. At the same time body mass and physical efficiency in animals of both groups did not differ in practice. Data on the functional status of autonomic nervous system were more informative. In rats with film-covered burn wound the dynamics of HRV indices had a biphasic character with the tending to normalization beginning from day 7 of CR/TI, whereas in case of an open wound HRV indices were characterized by monotonous growth until the end of observations. In the overall picture of the CR/TI in both groups of animals the sympathotropic effects of burn stress prevailed. Methods of mathematical analysis of HRV under conditions of CR/TI were for the first time used in this study. The research outcomes signify to the expediency to apply these methods for obtaining data on functional state of the autonomic nervous system in CR/TI models in small laboratory animals.
在联合辐射/热损伤（CR/TI）动态变化过程中，对近交系白色大鼠自主神经系统的功能状态特点及体能效率进行了研究。CR/TI模型是通过对24只大鼠进行4.37 Gy剂量水平的全身X射线照射并造成占体表12%的Ⅲ度烧伤来建立的。研究在CR/TI自然发展以及烧伤创面抗感染的条件下进行。12只大鼠的创面用碘和琥珀酸处理过的聚合物薄膜覆盖。在CR/TI的第3、7、14、21和28天，以及CR/TI之前（基准水平），记录心率变异性（HRV）指标、体能效率水平（在垂直杆上保持自身重量的时间）、体重指标、存活率和动物的平均寿命。为了记录清醒大鼠的心电图、校正运动伪迹并分析HRV，使用了原始软件程序。对R-R间期图进行时域和频域分析。采用滑动窗口技术（100个R-R间期，步长为10秒；分析时段——7分钟）。获得的数据表明，与“单纯”CR/TI相比，薄膜覆盖烧伤创面大鼠的存活率和平均寿命更高。同时，两组动物的体重和体能效率在实际中并无差异。关于自主神经系统功能状态的数据更具信息量。在薄膜覆盖烧伤创面的大鼠中，HRV指标的动态变化呈双相性，从CR/TI第7天开始趋于正常化，而在开放性创面的情况下，HRV指标的特点是直到观察结束一直呈单调增长。在两组动物CR/TI的总体情况中，烧伤应激的交感神经效应占主导。本研究首次在CR/TI条件下使用HRV的数学分析方法。研究结果表明，在小型实验动物的CR/TI模型中应用这些方法获取自主神经系统功能状态数据是适宜的。
