The effects of local x‐ray irradiation on the tail development of young axolotls

Regeneration of the tail of X-irradiated Xenopus tadpoles

“…Although it is widely accepted that the regenerative power of a younger animal is more than that of a grown-up and then again the regenerative capacity of urodeles is greater than that of anura. Xenopus tadpoles here were irradiated at a comparatively grown-up stage, but the results are diametrically opposite to those of Brunst [1950], In the present case, the unir radiated portion of the tadpole must, in some way, influence the regeneration to occur in the irradiated region. The regenerates seem to be the result of nothing more than dedifferentia tion and rediflerentiation and further growth.…”

“…The regeneration and growth of the tails of axolotls, 6-12 days after hatching, locally ir radiated with 1,000-6,000 r have been studied by Brunst [1950], The development of these tails was completely inhibited by all doses, growth being suppressed for 85-100 days. Further, Brunst and Figge [1951] studied the locally irradiated tails of axolotls, 10 days after hatching, at 150-1,200 r and observed development of secondary tails in 50% of the animals regenerated between 65 and 75 days after irradiation.…”

Investigation of the Lethal Effect of X-Irradiation on the Young Axolotl (Siredon mexicanum)

“…These giant connective tissue cells have not been observed after local X-irradiation. The macrophages which were described in many cases after local irradiation (14), especially during reduction of locally irradiated regenerating limbs (16), were found in only small numbers in the present material (in 11.5% of all animals). These cells also could be seen during reduction of limbs or tails of animals with irradiated body exclusive of the head.…”

“…It was mentioned that after total-body irradiation with 3000 or 6000 r all animals died (or were killed) during 30 or 40 days after treatment. The primary acute reaction after local irradiation, which was described in our previous paper (Brunst,14;Brunst et al,15), always occurred between 20 and 60 days after treatment. According to our observations, the following is typical for the primary acute reaction after local irradiation: formation of giant cell degenerating epithelium, reduction of the skin pigment layer, the presence of macrophages, signs of inflammation, suppression of mitotic activity, and in some cases the presence of a "zone of stimulation."…”

“…Many authors have described this very typical change after X-ray treatment (Brunst,14; also Brunst and co-workers, 15; also "swelling of cells," Bloom,20) and after treatment with radioisotopes (for example, after treatment with radioactive colloidal gold, Koletsky and Gustafson,21).…”