| Abstract |
New born BDIX strain rat received 0.1 mg of N-nitrosodimethylamine (DMN)
by subcutaneous injection. The kidney tumor that developed at left side
after 350 days was transplanted subcutaneously (S.C.) and intraperionealy
(I.P.) from 5th generations. Transplantable kidney tumor line was
successfully established, named NK-7801. In presence, NK-7801 is kept 46th
generations on the S.C. and 66th generations on the I.P. Both successful
transplantable rate were 100%. The average life-span shows 4 weeks on the
S.C. and 3 weeks on the I.P, Histological pattern of primary kidney tumor
showed nephroblastoma with tubular-like epithelial elements, but at NK-7801
it changes undifferentiated nephroblastoma having non-epithelial
elements alone. Ultrastructurally, tumor cells having irregular shape,
large nuclei and poor development of cytoplasmic organellae present in
the wide intercellular spaces. The most characteristic changes are that
nuclear envelope and cistern of rough endoplasmic reticulum become very
widly and consist amorphous substances in these lumina. Fibrillar
component of nucleolonemata and free ribosome of cytoplasm increase, and
also Golgi's complex are well development. These investigations indicate
that NK-7801 cells have immature and tumor elements. Biochemically, in
NK-7801 tissue, nuclease activities decrease and synthetic ratios of protein,
RNA and DNA than that of control kidney tissue. These results indicate
that nucleic acid synthesis is activated vigorously.
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