Studies on radiation renal damages. 1. Change of renogram following x-ray irradiation in the kidney of adult dog

摘要

1) Radiation renal damage was produced in 15 mongolian dogs, weighed 10 to 17 kg, by external X-ray irradiation of various dosages to the site of the left kidney. The renal functions following the irradiation was evaluated by renogram. 2) The experimental animals were devided into 5 groups. The doses of radiation to the 1 st, 2 nd, 3 rd, 4 th and 5 th groups were 1000r, 1500r, 2000r, 3000r and 1000r daily for 3 days totalling 3000r respectively. The dosage of each irradiation was standed for the skin dose of the site of left kidney. 3) Renogram of the irradiated animals using 131I-Hippuran showed a curve characterized by 3 different parts, namely the A-part which sharply rises in 20 to 40 seconds after injection, the B-part which follows and sustains the same level of the A-part and then rises abruptly until the maximum counts is obtained in 2 to 3 minutes and finally the C-part which falls gradually. 4) The kidney of irradiated side showed hypofunctions, corresponding to the dose of irradiation, which begun with prolongation of excretory segment, followed by flattering of functional segment and increase in the maximum counts with subsequent decrease. Nonfunctional pattern became to be recognized in the 1 st, 2 nd, 3 rd, 4 th and 5 th groups in about 40 weeks, 21 weeks, 16 weeks, 14 weeks and 30 days after irradiation respectively. 5) The kidney of non-irradiated side showed change of its renogram mark e dly around when the renogram of irradiated kidney became flat. Decreases in the functional segment and the maximum counts became first evident around 40 weeks after irradiation in the 1 st group and around 18 weeks in the 2nd group. In the 3rd group excretory segment became prolonged in 12 weeks, while in the 4 th group the changes were evident in the early irradiation period and showed non-functional pattern in 30 weeks. In the 5 th group similar non-functional renogram was observed in 30 days. 6) The above mentioned changes on renograms of the irradiated and non-irradiated kidneys were progressive step by step. 7) It will be coucluded to as s ume that performance of renography is worthwhile in evaluating separate kidney functions with simple and automatic means without complicated technique of GFR, RPF and RBF.