放射性腎障碍に関する研究 第2篇: 成犬腎の一側腎摘出後残腎X線照射後におけるレノグラム変化

Abstract

1) Radiation solitary renal damage was produced in 18 Mongolian dogs, weighed 10 to 17kg, by external X-ray irradiation of various dosages to the site of solitary kidney in 2 weeks after right nephrectomy. The solitary renal functions was evaluated at various times following irradiation for a long period of time. 2) The experimental animals were d evided into 6 groups. The doses of radiation to the 1st, 2nd, 3rd, 4th and 5th, group were 1000r, 1500r, 2000r, 3000r and 4000r respectively. The dosage of each irradiation was standed for the skin dose of the site of left kidney. 3) After the irradiation, animals of the 1st group are still healthy survived in maximum 400 days. However animals of the 2nd, 3rd, 4th and 5th groups died in 300 days, 180 days, 240 days and 28 days after irradiation respectively. These survived durations were almost same as that of unilateral renally irradiated groups. 4) Renogram of the irradiated solitary kidney sh o wed marked hyperfunctional pattern in 2 to 3 days after irradiation followed by hypofunctional patterns corresponding to the dose of radiation. This was initiated by prolongation of excretory segment and then was indicated by flattering of functional segment and decrease of maximum counts. In the 1st group the pattern of renogram showed only slight decrease in the slope of the B-part and prolongation of the C-part even in 1 year after irradiation. However, non-functional pattern was observed in the 2nd, 3rd, 4th and 5th groups in 25 weeks, 18 weeks, 16 weeks and aronud 30 days after irradiation respectively. 5) Comparing the renogram o f irradiated solitary kidney to that of irradiated unilateral kidney, it was found that the hypofunctional changes became evident earlier in the later group in each corresponding irradiated group. As the cause of this results, it was supposed that the solitary kidney recovered earlier from radiation damage due to its compensatory hypertrophy as well as absence of indirect effect of X-ray irradiation. 6) The progressive changes obtained by renogram fairly well coincided with histological alterations described in literatures.