Functional changes in the pig kidney following irradiation with fractionated doses of fast neutrons (42 MeVd-->Be).
The right kidney of female Large White pigs, approximately 14 weeks old, was irradiated with fractionated doses of fast neutrons (42 MeVd-->Be). The total doses used were 6.6-9.2 Gy. Changes in kidney function, assessed as the functional index (FI, where FI = irradiated kidney function/unirradiated kidney function) or as individual kidney glomerular filtration rate (GFR) and effective renal plasma flow (ERPF), were serially determined up to 104 weeks after irradiation using 99Tcm-DTPA and 131I-hippuran renography. The animals were then euthanized, the kidneys removed and weighed. A dose-dependent reduction in FI was seen within 13 weeks of irradiation. Measuring individual kidney function revealed a hyperaemic response in both irradiated and unirradiated kidney 4 weeks after irradiation. This was followed by a dose-dependent reduction in irradiated kidney GFR and particularly ERPF. The ED50 value for the impairment in ERPF, assessed as the percentage of irradiated kidneys exhibiting a > or = 50% reduction in ERPF, was significantly lower than that for GFR, i.e. 7.20 +/- 0.10 Gy compared with 8.44 +/- 0.07 Gy (p < 0.001). A dose-related reduction in irradiated kidney weight was also observed. These fast neutron-induced changes in renal function and weight are qualitatively similar to those observed following photon irradiation of the pig kidney.
Robbins
M E
ME
Research Institute (University of Oxford), Churchill Hospital, UK.
Barnes
D W
DW
Hopewell
J W
JW
Knowles
J F
JF
Rezvani
M
M
Sansom
J M
JM
D000818:Animals; D004307:Dose-Response Relationship, Radiation; D005214:Fast Neutrons; D005260:Female; D005919:Glomerular Filtration Rate / Q000528:radiation effects; D007668:Kidney / Q000033:anatomy & histology / Q000503:physiopathology / Q000528:radiation effects*; D009929:Organ Size / Q000528:radiation effects; D012079:Renal Circulation / Q000528:radiation effects; D013552:Swine; D013997:Time Factors