Adipose tissue diets

Interestingly, the significant difference of their concentrations between the abdominal adipose tissue-diet and the buttock adipose tissue-diet was PCC 0.621 and P<0.01, and PCC 0.255 and P<0.05 for 15 cis lycopene (56), respectively. 

The intake of one trans and total cis type mixtures irons and cis.) of the most hydrophobic carotenoid lycopene (3) was more closely related with the abdominal adipose tissue-diet concentration (PCC 0.408 P<0.10), or the abdominal adipose tissue-sen/iw concentration (PCC 0.384 P<0.10) than with SQTvm-diet concentration (PCC 0.078 P not noted). 

Minor changes of questionable biological significance observed in rats administered 5 mg/kg/day of endosulfan in a low-protein diet for 9 weeks include a decrease in capsular space and an increase in perirenal adipose tissue (Das and Garg 1981). 

Fatty acids are synthesized by an extramitochondrial system, which is responsible for the complete synthesis of palmitate from acetyl-CoA in the cytosol. In the rat, the pathway is well represented in adipose tissue and liver, whereas in humans adipose tissue may not be an important site, and liver has only low activity. In birds, lipogenesis is confined to the liver, where it is particularly important in providing lipids for egg formation. In most mammals, glucose is the primary substrate for lipogenesis, but in ruminants it is acetate, the main fuel molecule produced by the diet. Critical diseases of the pathway have not been reported in humans. However, inhibition of lipogenesis occurs in type 1 (insulin-de-pendent) diabetes mellitus, and variations in its activity may affect the nature and extent of obesity. 

Fat absorbed from the diet and lipids synthesized by the liver and adipose tissue must be transported between the various tissues and organs for utilization and storage. Since lipids are insoluble in water, the problem of how to transport them in the aqueous blood plasma is solved by associating nonpolar lipids (triacylglycerol and cholesteryl esters) with amphipathic hpids (phospholipids and cholesterol) and proteins to make water-miscible hpoproteins. 

Importantly, the mutant chicken exhibits lower levels of lutein and zeaxanthin in plasma and several other tissues in comparison with the control chicken, and that difference is already apparent in 1-day-old chickens and remains in 28-day-old chickens fed the same diet (Connor et al., 2007). In the WHAM chickens, the levels of lutein in the plasma, retina, skin, adipose tissue, liver and heart, respectively, have been found to be only 8%, 10%, 18%, 33%, 52%, and 60% of the corresponding levels in control chickens. Even though the diet in these chickens included three times more lutein than zeaxanthin and these ratios have been present in the plasma of both the control and WHAM chickens, there was a preferential accumulation of zeaxanthin over lutein in their retinas. 

Concern for the continued widespread use of chlordane centers on its ability to cause liver cancer in domestic mice. Other adverse effects in mammals, such as elevated tissue residues and growth inhibition, were frequently associated with diets containing between 0.76 and 5.0 mg chlordane/kg feed. Metabolism of technical chlordane by mammals results primarily in oxychlordane, a metabolite that is about 20 times more toxic than the parent compound and the most persistent metabolite stored in adipose tissues. Chlordane interactions with other agricultural chemicals produced significant biological effects in warm-blooded organisms, indicating a need for additional research on this subject. 

Liver histopathology and diarrhea recorded in all treated groups vs. none in controls. The 1000 mg/kg diet was the only ration to adversely affect the weight of all organs analyzed. After 5 weeks on PCP-free diet, residues were still measurable in adipose tissues of all treated birds (Stedman et al. 1980)... 

Mussalo-Rauhamaa H, Pyysalo H, Moilanen R. 1984. Influence of diet and other factors on the levels of organochlorine compounds in human adipose tissue in Finland. J Toxicol Environ Health 13 689-704. 

Following a single oral dose of 2,000 mg/kg of di-/ -ocLylphthalatc in rats, mono- -octylphthalate was detected in blood with peak levels observed at 3 hours and in the testes with peak levels observed at 6 hours (Oishi 1990). The biological half-life and mean residence time of mono-w-octylphthalate in blood were 3.3 and 5.4 hours, respectively. After 13 weeks of oral exposure of rats to di-w-octylphthalate in the diet at concentrations up to 5,000 ppm (350 and 403 mg/kg/day in males and females, respectively), the livers contained di -/ -oc1y lphthalate residues that were either below or just slightly above the detection limit (<3 ppm) (Poon et al. 1995). The adipose tissue of rats fed 5,000 ppm showed di-/ -octylphthalate residue levels of 15 ppm (males) and 25 ppm (females). This study is limited in that it did not analyze tissues for the presence of metabolites. 

The fat content of the US diet has increased very substantially over the past few decades. Currently more than 40% of dietary calories are consumed in the form of fat. This can easily lead to weight gain. The energy required for conversion of dietary fat to fat in adipose tissue involves the loss of only 3% of the calories in the dietary fat. In contrast, the energy requirement for conversion of dietary carbohydrate to fat in adipose tissue involves the loss of 23% of the calories in the dietary carbohydrate. Clearly, dietary fat is a great source of body fat. 

This subject is discussed in Chapter 15, but a brief summary is given here, as an introduction to fat metabolism. The three major components of a human diet are meat, fish and plants, and the fats associated with each component can be different. Meat usually comprises the muscle of mammals and birds but it is always associated with fat. Even apparently lean meat may have a high fat content a 250 g beef steak may contain 60 g fat in addition to its 80 g protein. Some of this will be adipose tissue between muscles the remainder is triacylglycerol (TAG) within the fibre. In addition, milk and other dairy products contain significant amounts of fat about a quarter of the fat in the average UK diet comes from dairy produce. 

Triacylglycerol (i) chylomicrons (ii) very low density lipoproteins intestine (diet) liver adipose tissue, muscle, lactating mammary gland... 

Long-chain fatty acids in the human diet are mainly palmitic (16C), oleic (18C) and stearic acids (18C) as well as the polyunsaturated fatty acids (18C, 20C and 22C). Almost all of the fatty acids in the diet have an even number of carbon atoms and are unbranched. Many are unsaturated. Indeed, in human adipose tissue, more than half of the total fatty acids are unsaturated (Chapter 11). 

The synthesis of fatty acids in humans takes place in the liver and adipose tissue. The rates of synthesis are normally relatively low in adults in developed countries, probably because the normal diet contains such a high proportion of fat which reduces the activities of enzymes involved in fatty acid synthesis by decreasing expression... 

A normal diet may not provide sufficient essential fatty adds to satisfy proliferation in trauma or infection, so that they are mobilised from adipose tissue. Muscle protein is broken down in trauma even on a normal diet (Chapter 18). 

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