DEVELOPMENT OF EXTRACRPOREAL THERAPEUTIC SYSTEM FOR THE INJURED ORGANS

1.常温保存系统的研制器官灌注机由保存箱、脉搏/交变脉率灌注泵、氧合器、输液泵、血氧监测(血氧浓度、pH、温度、湿度、压力、氧耗)和控制器组成。由于需要开发包含自然肾脏控制算法的软件才能正确使用灌注机，因此在不同灌注率、灌流压力和脉率的情况下进行肾脏的原位灌流。分别在120、145和195 mm Hg恒定灌流压力下进行2小时原位灌流。脉动可促进尿量、灌注率和肾小球滤过率。然而，有必要进行进一步的研究，因为在某些情况下会发生与氧耗减少相关的故障。生物电阻抗法测定大鼠肾脏保存3小时后的组织含水量用铂丝制成的四个电极和80微安(1 kHz~50 kHz)的交流电流测量大鼠肾脏的生物电阻抗。组织比重与同一部位的细胞外阻抗(Re)+细胞内阻抗(Ri)呈线性相关。不同防腐剂处理组的Re+Ri有显著差异，这与它们预防水肿病的能力相对应。用自旋松弛时间和质子密度测量保存器官的水分分布由于生物电阻抗法不能检测电极与器官直接接触的影响，因此需要用非侵入性测量来估计其程度。用核磁共振(0.5T)进行的基础研究表明，质子密度和自旋-空位驰豫时间分别代表总含水量和自由水/束缚水比。

1. Development of Normothermic preservation systemThe Organ perfusion machine which consists of the preservation box, the pulsatileno pulsatile/alternative pulse rate perfusion pump, the oxgenator, the infusion pump, the monitorings (Oxgen conc., pH, Temp., Humid., Pressure, Oxgen consumption), and the controller. Since development of software containing the control algorithm of the natural kidney is necessary to use the perfusion machine properly, in situ perfusion of the kidney was carried out at varying perfusions rate, perfusion pressure and pulse rate. Two hour in situ perfusions were carried out at constant perfusion pressure of 120, 145 and 195 mmHg, respectively. Pulsation promotes urine production, perfusion rate and glomerular fitration rate. However, further investigation is necessary because malfunction associated with decrease of oxgen consumption occured in some cases.2. Measurement of tissue water content by bioelectrical impedanceBioelectrical impedance of the rat kidneys stored for 3 hours were measured using four electrodes made of platinum wire and an alternative curent at 80muA (1kHz-50kHz). Linear correlation between tissue specific gravity and extra cellular impedance (Re) + intra cellular impedance (Ri) of the same portion. There was a significant defference in Re + Ri among the groups treated with a different kind of preservatives, which corresponded their abilities to prevent edema.3. Measurement of water distribution of the preserved organ by spin-latice relaxation time and proton density.Since we can not examinate the effect of direct contact of the electorode to the organ in bioelectrical impedance method, non-invasive measurment is required to estimate its degree. Basic study using NMR (0.5T) indecated that proton density and spin-latice relaxation time represented total water content and free/bounded water ratio, respectively.