Primary Pancreatic Tumours in Rats Fed P-Dimethylaminoazobenzene

Hoch-Ligeti, Cornelia

doi:10.1038/bjc.1949.33

Cited by 20 publications

(13 citation statements)

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“…Azaserine (5 mg/kg) was therefore subcarcinogenic for the rat pancreas (22). Nevertheless, the administration of this subthreshold dose of azaserine induced pancreatic cancer in more than 60% of rats fed raw soya flour for more than 60 weeks (10). The potentiating effects of raw soya flour on the development of azaserine-induced pancreatic cancer also occurred when the raw soya flour was administered only after the end of a 3-week course of 5 mg/kg-week azaserine (unpublished) but if, alternatively, raw soya flour-containing diets were given for only 12 weeks, no pancreatic cancer developed in the rats given azaserine for as long as 60 weeks (10).…”

Section: Effect Of Additional Carcinogensmentioning

confidence: 99%

“…The proportion ofrats developing pancreatic cancer is greater (up to 60%) in rats fed 100% raw soya flour for only 2 days each week for 60 weeks or more, with non-soya-containing chow for the remaining 5 days each week (4). All these values of incidence of pancreatic cancer are significantly greater than the maximal value of about 1% of "spontaneous" pancreatic neoplasms recorded in the literature (5), particularly bearing in mind that this value has been obtained from observations on rats fed "routine" diets, which have probably contained soya flour.…”

Section: Morphological Aspects Macroscopic Featuresmentioning

confidence: 99%

“…Similarly, rats receiving heated soya flour do not show abnormal increase in pancreatic weight during feeding for 2 years (4). Although a few microscopic and macroscopic nodules developed after feeding heated soya flour for 60 weeks or more, no animal fed heated soya flour developed pancreatic cancer (4 (6). These changes correlate with the growth of the gland and with the increased secretory response to stimulants of the pancreas of these animals (7).…”

Section: Morphological Aspects Macroscopic Featuresmentioning

confidence: 99%

“…Since casein elicits discharge of pancreatic enzymes when administered to rats (while albumin does not) (59) in a manner perhaps similar to raw soya flour, it seems probable that casein should not be used as "control" protein when studying the nutritional or carcinogenic effects of soybean protein. Indeed, it seems possible that cow milk may promote pancreatic carcinogenesis in rats given subthreshold amounts of an exogenous carcinogen (60).…”

Section: Implications For Potential Human Pancreatic Cancermentioning

confidence: 99%

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Effects of soybean flour on the pancreas of rats.

McGuinness¹,

Morgan²,

Wormsley³

1984

Environ Health Perspect

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We have reviewed the growth-promoting and carcinogenic effects of feeding raw soya flour to rats. If the raw soya flour-containing diets are fed for more than a year, about 10% of the animals develop pancreatic cancer. In addition, feeding raw soya flour markedly potentiates the action of even subthreshold amounts of pancreatic carcinogens. The raw soya flour therefore acts as a potent promoter, as well as a weak carcinogen. In view of this promotion, the rat fed raw soya flour is a sensitive model for screening pancreatic carcinogens.It is not known whether the human pancreas responds to dietary trypsin inhibitors in a manner similar to the rat. However, in view of the use of soya-based products in human nutrition-especially in infant foods-we urge that the effect of all soya-based products intended for human use be tested on the rat pancreas in long-term feeding studies, combined with subthreshold doses of azaserine to highlight any promoting activity of the product. It seems probable that if a product exerts no effect on the rat pancreas, the human pancreas will also be spared from noxious effects. Morphological Aspects Macroscopic FeaturesRaw soya flour-containing diets have been shown to produce enlargement of the rat pancreas after administration for as little as 10 to 20 days (1). The pancreatic enlargement has been shown to reflect both hypertrophy (defined as increase in cellular size and amount of protein per unit of DNA) (2) and also hyperplasia (increase in the amount of DNA and number of cells in the gland) (3). We have shown that the pancreatic growth-promoting effects continue, ifthe administration of raw soya flour is maintained, but becomes progressively more marked in an exponential manner at some time between 30 and 60 weeks of feeding raw soya flour-containing diets (4).During the period of pancreatic enlargement, the gland changes color to become dark red, reflecting increased vascularity and blood flow, as demonstrated by use of microspheres (unpublished results).Some time between 24 and 30 weeks after the start of raw soya flour-containing diets, small greyish patches become visible on the surface of the gland. Subsequently, overt nodules appear and increase in size (6). These changes correlate with the growth of the gland and with the increased secretory response to stimulants of the pancreas of these animals (7).After feeding raw soya flour-containing diets for 16 to 24 weeks, a few microscopic foci can be found scattered throughout the pancreas. The number and size of the nodules increases with the duration of feeding (4) Reversibility of Morphological ChangesThe pancreatic weights, protein content and morphological appearances revert to normal when rats are fed raw soya flour for 5 days (8), 4 weeks (9) and 6 months (unpublished observations) and then receive non-soyacontaining diets.If rats are fed raw soya flour for as long as 6 months and the diet is then changed to non-soya-containing chow, nodules are not found at death a year or more later, so that histologically the pancreas o...

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Section: Effect Of Additional Carcinogensmentioning

confidence: 99%

Section: Morphological Aspects Macroscopic Featuresmentioning

confidence: 99%

Section: Morphological Aspects Macroscopic Featuresmentioning

confidence: 99%

Section: Implications For Potential Human Pancreatic Cancermentioning

confidence: 99%

See 2 more Smart Citations

Effects of soybean flour on the pancreas of rats.

McGuinness¹,

Morgan²,

Wormsley³

1984

Environ Health Perspect

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“…Recently, Hoch-Ligeti (1949) reported the production of liver tumours in 12 out of 21 rats killed after 7 months' feeding of 10 per cent. chilli (Cap8icumfrui-tewcens and C. annuum) in a semi-synthetic deficient diet; this contained ardein, the protein of ground nuts.…”

Section: Control Animalmentioning

confidence: 99%

Primary Liver Tumours in Rats following Feeding with Alkaloids of Senecio jacobaea

Cook¹,

Duffy²,

Schoental³

1950

Br J Cancer

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Pancreatic neoplasms in an animal model: Morphological, biological, and comparative studies

Pour

Möhr

Cardesa

et al. 1975

Cancer

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After a short latency (15 weeks), a 100% incidence of pancreatic neoplasms was induced i n Syrian golden hamsters, following the administration of 2,2'-dihydroxy-di-n-propylnitrosamine (DHPN). D a t a extracted from reports of h u m a n pancreatic neoplasms were compared with findings relative to the induced neoplasms. The latter resembled h u m a n pancreatic tumors, in both biological and morphological aspects. The authors greatly appreciate the encouragement and critical advice of Dr. P. Shubik.Received for publication July 2, 1974. low rates of cancer production,1~~1~~*0~43~~1 3 ) MATERIALS AND METHODSRandom bred, 8-week-old Syrian golden hamsters from the Eppley colony were kept under standard laboratory conditions and given Wayne Pellet diet and water ad libitum.The animals, in three groups of 20 males and 20 females each, received weekly subcutaneous injections for life of 2,2'-dihydroxy-di-n-propylnitrosamine (DHPN) at the following doses:Group 1, 500 mg/kg body weight; Group 2, 250 mg/kg b.w.; and Group 3, 125 mg/kg b.w. Twenty male and 20 female controls received the olive oil solvent and were sacrificed a t the experiment's 44th week, when the last DHPNtreated animal died. Following complete autopsies, tissues were fixed in 10% buffered formalin; Paraplast sections were stained with hematoxylin and eosin.Step sections and special stainings (using periodic acid-Schiff, Alcian blue, Masson's trichrome, and Bodian's and Gomori's silver methods) were prepared from each pan'creas. The effective number of animals corresponds to the number of pancreases which could be evaluated histologically. The tumor latencies were determined in correlation with the length of survival time dating from the experiment's beginning. Table 1 contains the data concerning pathologic findings, number of animals, their average survival times, body weights, and the incidence and latency of the pancreatic n e e plasms. Treated animals developed diarrhea and presented weight losses at about 16 weeks 379 RESULTS

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Primary Pancreatic Tumours in Rats Fed P-Dimethylaminoazobenzene

Cited by 20 publications

References 0 publications

Effects of soybean flour on the pancreas of rats.

Effects of soybean flour on the pancreas of rats.

Primary Liver Tumours in Rats following Feeding with Alkaloids of Senecio jacobaea

Pancreatic neoplasms in an animal model: Morphological, biological, and comparative studies

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