|Budget Amount *help
¥2,600,000 (Direct Cost : ¥2,600,000)
Fiscal Year 1993 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1992 : ¥1,600,000 (Direct Cost : ¥1,600,000)
1. Development of Normothermic preservation system
The 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 impedance
Bioelectrical 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.