Effects of Internal Irradiation of Mice with P32

Abstract

In continuation of the studies of the histologic effects of doses of 25 [mu]c, 250 [mu]c and 2 mc of P32 in mice the changes in the following organs are described: Ovaries[long dash]The most characteristic and consistent change is a reduction in total amt. of ovarian tissue. The factors which contribute most heavily to this are (1) a diminished number of graafian follicles, (2) absence of corpora lutea, and (3) marked condensation of the stroma. This last factor, plus the late development of interstitial tissue, is considered the most distinctive post-irradiation effect of P32 on the ovary. An absolute sterilization dose of P32 short of a lethal dose has not been found in mice. Cysts of ovarian structure were not encountered. Testis[long dash]The least mature spermatogenic cells were the first to show radiation injury. After a dose of 250 [mu]uc of P32 almost all spermatogonia had disappeared after 9 days. The primary spermatocytes were the next to show injury, disappearing after 20 days. The secondary spermatocytes and Sertoli cells were not appreciably altered. No mature sperm or spermatids were found at 50 days. The interstitial cells showed 2 changes: (1) increased vacuolization (2) proliferation. Kidneys[long dash]At 10 days after injn. of 250 [mu]c, there was occasional shrinking of the epithelial cell-lining of the renal tubulus. No changes were noticed in the glomeruli. On the 13th to 15th day after injn. the degenerative effect on the tubulus appeared maximal, and there was beginning regeneration of the epithelial cells. At 50 days no radiation changes could be noticed. Adrenals[long dash]Except for some congestion, no radiation change was noticeable. Digestive tract[long dash]No morphologic changes in esophagus and stomach. Two days after injn. of 250 [mu]c, mitoses of the basal glandular epithelium of the ileum had stopped and superficial desquamation occurred. At 4 days mucosa appeared normal. No histological changes were found which could be correlated with the severe diarrhea exhibited by this group. The lethal dose of 2 mc caused marked changes in the terminal ileum and colon consisting in desquamation of the epithelium of the villi and vacuolization. The submucosa was edematous and congested. No gross hemorrhage was noted. Spinal cord[long dash]In a few instances small petechial extravasations of blood were noted in the ventral horns, and in 2 instances 2 large hematomas were found in the cord. Lungs[long dash]Showed congestion and frequently pneumonia. Liver[long dash]No nuclear changes in the parenchymal cells were noted early after injn. At 15-20 days compensatory ectopic hematopoiesis occured. Max. effect of irradiation was noticed about 20 to 50 days after injn.