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The effects of plasma lipid overload on pancreatic islet function and on mineral imbalance are issues under debate. However, the outcomes may be biased by the different metabolisms of different species. This prospective study evaluated whether a high fat diet intake changed the distribution of physiologically relevant elements within pancreatic endocrine and exocrine tissues of Sprague Dawley rats and New Zealand White rabbits. Nuclear microscopy techniques provided images of the specimen density and structure as well as the elemental distributions and quantification of P, S, Cl, K, Ca, Fe, and Zn using unstained cryosections of pancreas. Our results indicate that pancreatic islets in normal rats and rabbits had lower tissue density and higher Ca, Fe, and Zn content compared to exocrine tissue, and that rabbit islets exhibit the highest Zn content (3,300 μg/g in rabbits versus 510 μg/g in rats). Fat diet intake resulted in large deposits of fat in the pancreas, which modified the density contrast of tissues and also resulted in a twofold decrease of Ca and Zn concentrations in islets of both rats and rabbits. This result indicates that a fat diet leads to a reduction in essential trace element concentrations in pancreas, which in turn may hamper endocrine function.

We have carried out measurements of energy balance in hypothyroid rats fed a low-fat or a high-fat diet for eighteen days. We have also measured cephalic and processing thermic effect of food (TEF) after a low-fat or a high-fat meal. Body lipid gain, carcass lipid content and gross efficiency were significantly (P < 0·05) higher in hypothyroid rats fed a high-fat diet compared with hypothyroid rats fed a low-fat diet, while metabolizable energy intake and energy expenditure remained unchanged. Cephalic TEF after a low-fat meal was significantly (P < 005) lower in hypothyroid rats fed a high-fat diet compared with hypothyroid rats fed a low-fat diet, while it was significantly (P Our results indicate that hypothyroid rats are unable to develop increased energy expenditure and increased TEF in response to a high-fat diet. European Journal of Endocrinology 136 309–315

The rationale for primary prevention of cardiovascular disease (CVD) in young people is based on the applicability to youth of the causal aetiologic model of CVD among adults. Young people in developed countries exhibit early atherosclerotic lesions, as well as elevated physiological risk factors. Young people in the United States consume a higher fat diet than recommended, approximately half are physically active and nearly 1 in 5 graduate from high school as regular cigarette smokers. Not only are risk factors and risk behaviours evident in youth, but they appear to track through adolescence and into adulthood. This review suggests that early prevention efforts are prudent and may be critical.

T. FUJISAWA, K. AIKAWA, T. TAKAHASHI, S. YAMAI, K. WATANABE, Y. KUBOTA AND M. MIYAOKA. 2001. The β-glucuronidase activity of intact cells of Clostridium perfringens was not influenced by the presence of either 0·09 or 0·19% lactic or butyric acids. In contrast, the enhanced enzyme activity of intact cells due to sodium deoxycholate was significantly decreased by the presence of these acids. These results suggest the possibility that the development of cancer due to the intake of a high fat diet may be inhibited by the presence of organic acids produced by intestinal bacteria.

Previous experiments have shown that a high fat diet changes incidence and tumour sites by N-nitroso-dialkylamines. The purpose of this study was to examine the effect of high and low fat diet on DNA methylation 6 weeks after the end of a chronic N-nitrosodimethylamine (NDMA) exposure (total dose 150 mg/kg). The concentration of O6-methyldeoxyguanosine (O6-MedG) in liver DNA was measured by immunoassays. The level of O6-MedG persisted 6 weeks after the last dose of NDMA and was 6-fold higher (P less than 0.05) in animals on high fat as compared to low fat diet. In another experiment, in which rats on a low and high fat diet received a single NDMA dose (2 mg/kg), the time-dependent removal of O6-MedG from liver and the hepatic O6-methylguanine DNA-alkyltransferase activity was not modified by the type of diet. These results indicate that a high fat diet enhances DNA methylation in the liver, after chronic treatment by NDMA, and that this effect is likely to be responsible for an increased incidence of liver haemangiosarcomas.

Two groups of 20 male Sprague-Dawley rats each were given azoxymethane subcutaneously (8 mg/kg body wt) and fed a normal diet or one high in beef fat. Control groups were not given azoxymethane. The rats on the fat diet consumed less food and gained significantly more weight than the animals on the normal diet. Those given high fat and azoxymethane developed more intestinal tumors than did the dietary controls receiving the carcinogen. Furthermore, they had a greater number of larger tumors and more metastases than did the animals fed normally. No intestinal tumors were observed in control groups not receiving azoxymethane. The results show that the diet high in beef fat enhances the carcinogenic effect of azoxymethane in the rat.