Radiation Nephropathy in Mature Pigs Following the Irradiation of Both Kidneys

Publisher Website
Google Scholar
Abstract
Both kidneys in mature female Large White pigs, ca. 45 weeks old were irradiated with single doses of 7.8-14.0 Gy of 60Co .gamma.-rays. Radiation-induced changes in renal function were assessed on the basis of sequential individual measurements of kidney glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) for up to 24 weeks after irradiation. At the same time intervals blood samples were taken to determine plasma renin levels and the haematological status of each animal. Two weeks after irradiation the ERPF and in particular the GFR was increased. This was followed by a pronounced, dose-dependent, decline in renal haemodynamics. Minimal functions levels were observed 8-12 weeks afte irradiation. Function then somewhat recovered. There was a significant (R.gtoreq.0.98; p < 0.001) inverse relationship between the mean values of GFR and ERPF, determined at 4-24 weeks after irradiation, and the radiation dose. After a dose of 7.8 Gy the reduction of ERPF was greater than that for GFR. However, a higher doses both parameters were reduced to an equal extent. The resulting slope of the dose-effect curve for impaired renal function versus dose was significantly steeper for GFR than that for ERPF (p < 0.001). There was a significant reduction (p < 0.002) in the erythrocyte count, the haematocrit and haemoglobulin levels within 6-8 weeks of irradiation; this anaemia was characterized as anormochromic normocytic anaemia. There were no marked changes in plasma renin levels as a result irradiation. The pathogenesis of late radiation-induced damage to the kidney is discussed in the light of these findings.