DEVELOPMENT TO HATCHING OF CHICK EMBRYOS GIVEN EARLY TREATMENT WITH TRITIATED THYMIDINE
Comparative effects of irradiation from tritlum and 250-kv x rays were studied in 2- to 3-day-old chick embryos. Through a hole in the shell, 50 mu C thymidine-H/sup 3 was applied to the 60- and 69-hr embryos, whereas 200-r x-ray doses were given through the shells of 64-hr embryos. Of 23 control embryos, 12 (52%) hatched, while only 7 of 25 (28%) thymidine-H/sup 3/ treated embryos hatched. Of these seven, three appeared to be normal, while the remaining four had defects involving one or both hind limbs. Limb injuries included slight weakness of a foot (89-hr), paralysis of both hind limbs (69-hr), and spastic paralysis of both feet (two, 60-hr). Three of the controls were also defective. Autopsy on a gross basis revealed normal morphology in all chicks of both the control and treated groups; average wt of normal controls was 39 g, as opposed to 35 g for treated chicks. Brain samples taken one day following hatching from treated chicks contained over 10 times the background radiation as measured in untreated controls. Only one of the 11 x-irradiated embryos hatched, although the majority lived to hatching age and were grossly normal. Thus, with hatching as the criterion, thymidine-H/sup 3/ is considerably less injurious than the x irradiation. However, some effects occurred in the thymidine-H/sup 3/ treated chicks for a smaller proportion of these than the controls hatched. Development was a little slower, slightly prolonging both the period of incubation and the period of hatching; and gross defects in behavior appeared in a higher proportion of the treated than of the control group, although again not significantly. In both the thymidine-treated and control groups the defects were of neural or muscular origin, affecting the hind limbs, but were more severe in the treated ciucks. It is concluded that 50 mu C of thymidine-H/sup 3/ applied to 2- to 3- day chick embryos is less injurious than 200-r x irradiation. (BBB)
- Research Organization:
- Univ. of Texas, Galveston
- NSA Number:
- NSA-17-038840
- OSTI ID:
- 4634578
- Journal Information:
- Texas Rept. Biol. Med., Journal Name: Texas Rept. Biol. Med. Vol. Vol: 20
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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