Radiation-induced proliferation in contralateral unirradiated kidneys.
Following irradiation of a single kidney in mice, the weights and labeling indices in the irradiated and contralateral unirradiated kidneys were measured. Three to 12 months after irradiation we found that the proliferation of proximal tubule cells was increased not only in the irradiated kidney but also in the contralateral unirradiated kidney. The labeling index in the contralateral unirradiated kidney did not increase in the first month after irradiation but it did in the irradiated kidney. Contralateral kidney weight increased as the weight of the irradiated kidney decreased. We suggest that cell proliferation in the contralateral kidney was probably induced through a humoral growth factor beginning 3 months after irradiation. We postulate that induced cell proliferation in the irradiated kidney is a result of a local factor at 1 month and of local and humoral factors at later times.
Otsuka
M
M
Department of Experimental Radiotherapy, University of Texas M.D. Anderson Cancer Center, Houston 77030.
Meistrich
M L
ML
D000818:Animals; D001835:Body Weight; D002455:Cell Division / Q000528:radiation effects*; D005260:Female; D007668:Kidney / Q000166:cytology* / Q000528:radiation effects*; D007687:Kidney Tubules, Proximal / Q000166:cytology / Q000528:radiation effects; D051379:Mice; D008809:Mice, Inbred C3H; D013047:Specific Pathogen-Free Organisms