HISTOPATHOLOGICAL AND BIOCHEMICAL ANALYSES OF TRANSPLANTABLE RENAL ADENOCARCINOMA IN RATS INDUCED BY N-ETHYL-N-HYDROXYETHYLNITROSAMINE

  • 1 January 1984
    • journal article
    • research article
    • Vol. 44  (4) , 1664-1670
Abstract
Transplantable renal adenocarcinoma can be readily induced in Wistar strain rats by initiation with N-ethyl-N-hydroxyethylnitrosamine followed by promotion with .beta.-cyclodextrin. The transplantability rates of the tumors by s.c. inoculation in newborn rats were 33 and 50%, respectively, for tumors of the 1st and 2nd passages, and 100% for both 3rd and 4th passages. The transplantability rates were affected by route of inoculations; rates of 50 and 100% were observed for s.c. and i.p. inoculations, respectively. The growth rate of tumors induced by i.p. inoculation was 3-fold higher than that induced by s.c. injection. Macroscopically, most of the tumors grew in the s.c. tissue of inoculation sites. However, invasive growth of tumors in spleen, liver, stomach, peritoneum and intestine were seen in 50% of the animals inoculated i.p.; metastatic cancers to lung were seen in 16%. Histologically the tumors were well-differentiated adenocarcinomas composed of uniform cells resembling kidney tubular cells, and appeared to be derived from normal kidney tissues. A 5-fold decrease in .gamma.-glutamyl transferase activity in tumor tissues was found as compared with that of nontumorous kidney tissues. Electrophoretic analysis of cellular proteins in polyacrylamide gels revealed that tumor tissues exhibited 5 new polypepties with MW of 81,000, 64,000, 59,000, 50,000, and 36,000 which were either lacking or undetectable in the nontumorous area and control kidney. In addition, protein banding patterns of transplantable renal tumor appeared to be more heterogeneous than those of primary kidney tumor.