Spontaneous Tumors and Common Diseases in Two Colonies of Syrian Hamsters. III. Urogenital System and Endocrine Glands2

Pour, Parviz M.; Möhr, U.; Althoff, J.; Cardesa, Antonio; Kmoch, Norbert

doi:10.1093/jnci/56.5.949

Cited by 55 publications

(29 citation statements)

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“…The histomorphologic appearance of these cells resembles oncocytes or hepatocytes. Similar cells in the pancreas have been reported in man (9), developing spontaneously (8,10,17) or induced experimentally (1 1, 12, 15, 16) in hamsters, and observed in chemicallytreated rats (1,5,7,13). However, no spontaneous occurrence of this alteration in the rat pancreas has been reported.…”

supporting

confidence: 76%

“…This may be partly due to a larger number of rats of this age in the study population. Nevertheless, this lesion has also been observed in aging hamsters (10,17), but no relation with age and clinical changes was observed in one report (8). Although a frequent association of fatty replacement with this condition was observed (5,17), this lesion and others, i.e., ductal replacement, islet cell hyperplasia, and focal inflammation, observed in some of these rats, are common spontaneously occurring lesions in aging rats of this strain and are not believed to relate to the development of eosinophilic hypertrophic cells.…”

Section: Discussionmentioning

confidence: 90%

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Focal Eosinophilic Hypertrophic Cells of the Rat Pancreas

Chiu

1987

Toxicol Pathol

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Focal spontaneously occurring eosinophilic hypertrophic cells, histomorphologically resembling oncocytes and hepatocytes, were observed in the pancreas from 1 1 (0.3%) of4,177 Sprague-Dawley rats, 3 to 26 months old. The age of these eleven rats ranged from 13 to 25 months. The incidence was not dimerent between sexes. The altered cells were usually scen in the peri-insular area. Two types of foci, uniform and pleomorphic, were classified on the basis of uniformity of size of the altered cells within a focus. The origin and nature were not determined for the altered cells/foci reported in this study but they were not considered to be neoplastic. INTRODUCTIONWith the increasing number of rats used in toxicity and carcinogenicity studies in recent years, many common spontaneously occurring lesions in various organs and tissues have been reported. Among the frequently described lesions of the pancreas are atrophy, inflammation, and hyperplastic or neoplastic lesions of exocrine and endocrine tissues. A recent report (2) from this laboratory has shown that a distinct spontaneous lesion of pancreatic acinar cells, designated as hypertrophic focus, commonly occurs and increases significantly in frequency in aging Sprague-Dawley rats.During histologic examination of the pancreas of the same strain of rats, we have also observed focal cellular alterations characterized by groups of large cells with eosinophilic cytoplasm. The histomorphologic appearance of these cells resembles oncocytes or hepatocytes. Similar cells in the pancreas have been reported in man (9), developing spontaneously (8,10,17) or induced experimentally (1 1, 12, 15, 16) in hamsters, and observed in chemicallytreated rats (1,5,7,13). However, no spontaneous occurrence of this alteration in the rat pancreas has been reported. The origin and nature of these cells remains uncertain. This report describes the spontaneous occurrence and histomorphology of focal eosinophilic hypertrophic cells of the pancreas in eleven Sprague-Dawley rats.

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confidence: 76%

Section: Discussionmentioning

confidence: 90%

Focal Eosinophilic Hypertrophic Cells of the Rat Pancreas

Chiu

1987

Toxicol Pathol

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“…However, the rates of renal cell tumors were 11% (2/19), 20% (4/20), 6% (1/17), 0% (0/19), and 0% (0/20), respectively, in groups given 2000, 500, 250, 125, or 0 ppm. Although the incidences were relatively low and were not statistically different, the results seemed to indicate the potential for KBrO3 to induce renal cell tumors in male hamsters, inasmuch as the incidences of spontaneous kidney tumors were extremely low in this rodent species (15)(16)(17).…”

Section: Dysplastic Foci (Df)mentioning

confidence: 83%

Long-Term in Vivo Carcinogenicity Tests of Potassium Bromate, Sodium Hypochlorite, and Sodium Chlorite Conducted in Japan

Kurokawa¹,

Takayama²,

Konishi³

et al. 1986

Environmental Health Perspectives

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Long-term in vivo carcinogenicity tests of potassium bromate (KBrO3), sodium hypochlorite (NaClO), and sodium chlorite (NaClO2) have been conducted in Japan from 1977 to 1985. In these investigations, groups of approximately 50 male and 50 female F344 rats or B6C3F1 mice were given solutions of the compounds as their drinking water ad libitum at two dose levels determined on the basis of preliminary 13-week tests. Control animals were given distilled water.The carcinogenic potential of KBrO3 was tested by administering doses of 500 or 250 ppm to rats for 110 weeks. Significantly elevated incidences of renal cell tumors in males and females and mesotheliomas of the peritoneum in males as compared to controls were observed. When female mice were given KBrO3 at doses of 1000 or 500 ppm for 78 weeks, no significant differences in tumor incidences between experimental and control groups were apparent.NaClO was administered to male and female rats, respectively, at doses of 1000 or 500 ppm and 2000 or 1000 ppm for 104 weeks. In mice, NaClO was given at doses of 1000 or 500 ppm to either sex for 103 weeks. The incidences of tumors in NaClO-treated and control animals of both sexes were not significantly different in both rat and mouse studies.NaClO2 was given to rats of both sexes at a dose of 600 or 300 ppm for 85 weeks. No statistically significant differences were observed in the incidences of tumor formation between NaCI02-treated and control groups of both sexes. NaCI02 was administered to mice at a concentration of 500 or 250 ppm for 85 weeks. In males, the combined incidences of hyperplastic nodules and hepatocellular carcinomas of the liver in a low-dose group, and adenomas and adenocarcinomas of the lung in a high-dose group, were marginally increased compared to controls (p<0.05). However, these incidences in treated males were within the range of values of historical control data in our program.We concluded that KBrO3 was carcinogenic in rats of both sexes. NaClO was not carcinogenic in either rats and or mice under the conditions of the present studies. Although NaClO2 was shown to be noncarcinogenic in rats, the results for mice were evaluated as inconclusive. Also the results of two-stage mouse skin carcinogenesis using KBrO3, NaClO, and NaCl02 are presented. The necessity for further testing of oxidant chemicals to determine potential carcinogenic and/or promoting effects is suggested in view of the recently proposed role of active oxygen species in carcinogenesis.

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“…It is relevant that spontaneous renal tumors in the hamster are essentially nonexistent (2)(3)(4). Evidence is beginning to emerge from our laboratory on the general nongenotoxic sequence of events leading to estrogen-induced neoplastic transformation in the hamster kidney (5).…”

Section: Introductionmentioning

confidence: 99%

Estrogen Carcinogenesis in the Hamster Kidney: Role of Cytotoxicity and Cell Proliferation

Li¹,

González²,

Banerjee³

et al. 1993

Environmental Health Perspectives

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Both natural and synthetic estrogens are capable of inducing renal neoplasms in Syrian hamsters with an incidence approaching 100%/. Neither the sequence of events nor the mechanisms involved in estrogen carcinogenesis in this model have been established. Results presented here indicate that estrogen induces renal tubular damage in the hamster kidney that is progressive and cumulative. Tubular injury was evident both as abnormal or lost microvilli, accumulation of cytoplasmic lipid droplets, vacuolization, and increases in secondary and tertiary lysosomes after 1.5 months of diethylstilbestrol (DES) treatment. Increasing tubular damage was evidenced by the detachment of tubular cells, cell debris, and occluded renal tubular lumens. In an effort to repair proximal tubular damage in the hamster kidney elicited by estrogens, a 4.0-fold increase in proximal tubule BrdU labeling was evident at 4 months of DES or 170-estradiol (E2) treatment and in earlier estrogen treatment periods (1-3 months). During this period, there was a significant increase in aneuploid cells in the hamster kidney, the near diploid frequency increased more than 6.0-fold, and the near tetraploid frequency increased at least 3.0-fold between 1.5 and 3.5 months of estrogen treatment. Based on these data, the early sequence of events leading to estrogen-induced renal neoplastic transformation in the hamster is presented.

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Spontaneous Tumors and Common Diseases in Two Colonies of Syrian Hamsters. III. Urogenital System and Endocrine Glands2

Cited by 55 publications

References 0 publications

Focal Eosinophilic Hypertrophic Cells of the Rat Pancreas

Focal Eosinophilic Hypertrophic Cells of the Rat Pancreas

Long-Term in Vivo Carcinogenicity Tests of Potassium Bromate, Sodium Hypochlorite, and Sodium Chlorite Conducted in Japan

Estrogen Carcinogenesis in the Hamster Kidney: Role of Cytotoxicity and Cell Proliferation

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