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Query: UMLS:C0028754 (obesity)
 124,988 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In order to test whether or not overeating of a nutritionally adequate diet with reasonable fat content could result in significant fat accumulation in the liver, male Sprague-Dawley rats were provided with free access to either a nutritionally adequate liquid diet with 35 per cent of calories as fat or a regular diet (controls) for 3 months. After the feeding period, body weight, Lee index, and epididymal adipose tissue weight, were significantly greater in rats fed with the liquid diet than in the controls. Liver weight, hepatic triglyceride levels were also greater in the liquid diet group. Histologically, remarkable fatty infiltration was observed predominantly in periportal areas in rats fed with the liquid diet ad libitum for 3 months. Compared to a large body of the literature concerning diet-induced obesity in experimental animals, information on animal models of fatty liver by dietary manipulations is insufficient. The results of this study clearly indicate that the overeating of a nutritionally adequate diet with reasonable fat content could result in remarkable fat accumulation in the liver in rats.
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PMID:Fatty liver in rats induced by excessive intake of a nutritionally adequate liquid diet. 344 Jun 81

Adult male golden hamsters with continuous access to Purina chow, water and either 15, 30 or 45% ethanol (v/v) for 14 weeks derived an average of 34, 37 and 22%, respectively, of their total calories from ethanol. Animals in the 15 and 45% ethanol groups derived up to 12.0 and 9.9 kcal/day, respectively, from ethanol, but the Purina chow intakes of these animals were such that their total caloric consumption and their body weights did not significantly exceed those of a control group having access only to Purina chow and water. In contrast, the 30% ethanol group derived up to 16.4 kcal/day from ethanol, and consistently consumed 25% more total calories than the control group, despite eating significantly less Purina chow. Furthermore, hamsters in the 30% ethanol group were 27% heavier and had significantly larger epididymal and retroperitoneal fat pads than controls. Similarities are noted between ethanol-induced obesity in hamsters and the dietary obesity which has been observed in rats having continuous access to Purina chow and a 32% sucrose solution.
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PMID:Voluntary ethanol consumption and obesity in golden hamsters. 351 15

Four lines of mice, two lines selected for rapid growth (large body weights) (M16 and H6) and their unselected control lines (ICR and C2, respectively), were examined for traits related to obesity. The M16 line is obese while the other three lines are normal in body composition at 10 weeks of age when fed stock diet. In experiment I, mice were fed stock diet and examined at intervals from 4 to 22 weeks of age. Mice were fed either a high-carbohydrate or high-fat diet in experiment II and examined at 4, 6 and 10 weeks of age. The traits measured were serum glucose, serum insulin and in vitro insulin responsiveness of diaphragm muscle. Epididymal adipose cellularity was determined at 10 weeks of age. Insulin responsiveness was determined for the diaphragm muscle by 2-deoxyglucose uptake. Body weights differed significantly (M16 greater than H6 greater than ICR greater than C2, P less than 0.01). The M16 obese line was hyperglycemic and mildly hyperinsulinemic while the H6 line was hypoglycemic and normoinsulinemic. Basal 2-deoxyglucose uptakes by diaphragm muscle were similar among lines while the insulin-stimulated uptake by M16 and H6 lines was less (P less than 0.01) than the stimulated uptake by their control lines. Diet did not affect basal uptakes, but high-fat diets reduced (P less than 0.01) the insulin stimulated uptakes when compared to the high-carbohydrate diet. Selected lines had more and larger epididymal adipocytes than control lines when fed the stock diet (P less than 0.01). Decreased insulin responsiveness of muscle tissue among the lines occurred concomitantly with an increase in adipocyte size.
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PMID:Insulin responsiveness of diaphragm tissue and adipose cellularity in mice selected for rapid growth. 353 7

Weanling male Sprague-Dawley rats received bilateral electrolytic lesions in the dorsomedial hypothalamic nuclei (DMNL rats); sham-operated rats served as controls. All animals were fed lab chow for 15 postoperative days. At that time they were subdivided into two groups each. One DMNL and one control group continued to be fed lab chow until the termination of the experiment on postoperative day 116. A second DMNL and control group were fed a high-fat diet and 32% sucrose solution (HF/SS diet). All DMNL rats showed reduced body weight and linear growth, but the HF/SS diet depressed these parameters further below the levels of the chow-fed groups. Both DMNL and control rats fed HF/SS had more carcass fat, heavier epididymal fat pads, more carcass fat per calories eaten, higher plasma levels of glucose, glycerol and free fatty acids but lower insulin levels than chow-fed DMNL rats and controls. This occurred in the face of lower body weights and caloric intake. Neither growth hormone nor insulin showed lesion effects. Rats with DMNL exhibited the same inverse relationship between plasma insulin and free fatty acids as controls. The data indicate that DMNL rats respond to the HF/SS diet essentially like sham-operated controls, i.e., they develop dietary obesity. Although they do show some small deficits, their lipogenic capacity is actually significantly greater than that of HF/SS-diet fed controls.
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PMID:Effect of palatable diet on growth, caloric intake and endocrine-metabolic profile in weanling rats with dorsomedial hypothalamic lesions. 354 85

The effects of long-term moderate food restriction were assessed in lean and obese male Zucker rats. A 30% reduction in food intake from 5 to 68 wk of age resulted in parallel lowering of body weight in both lean and obese rats compared to their respective ad libitum-fed control groups. In lean rats, epididymal and retroperitoneal fat pad weights and cell size were lowered by food restriction. In obese rats there was an effect of food restriction on growth of the epididymal pad but not the retroperitoneal pad. Hyperinsulinemia, hyperlipidemia and elevated serum albumin levels, as well as higher activity of lipogenic enzymes, were also not affected by food restriction in the obese rat. In a second experiment, long-term food restriction resulted in greater glucose conversion to CO2 in response to insulin in adipocytes from lean rats but not obese rats compared to their respective control groups. These results indicate that food restriction throughout the first year of life in the obese Zucker rat does not alter the development of hyperplastic obesity and insulin resistance.
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PMID:Effects of long-term moderate food restriction on growth, serum factors, lipogenic enzymes and adipocyte glucose metabolism in lean and obese Zucker rats. 355 7

The activity of cathepsins A, B, C, D, phospholipases A1 and A2, and aryl sulphatases A and B was studied in hepatic lysosomas, adipocytes of epididymal fatty tissue and in platelets of rats aged 2,5 and 24 months differing in the character of milk feeding. It was found that excessive feeding in the neonatal period resulted in a decrease of the lysosomal proteinase activity by 18-33% in 24-month animals, while phospholipase A2 activity rose 1,4-2.2-fold. Phospholipase A2 activity proved to be also increased in adipocytes of obese rats. Obese rats' platelets were characterized by a drastic (2-3.5-fold) activation of cathepsin C, and phospholipase A1 activity rose by 55% at all the stages of the ontogenesis. It is suggested that the changes in the lysosomal hydrolases activity may reflect the platelet function in the disordered lipoprotein metabolism.
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PMID:[Effect of neonatal nutrition on the enzyme activity of liver lysosomes, adipocytes and thrombocytes in young and old rats]. 370 43

The growth pattern of visceral organs was investigated in monosodium L-glutamate (MSG)-treated obese mice with hypothalamic lesions. Male Jcl-ICR strain mice were subcutaneously injected with MSG, 2 mg/g of body weight daily, for five days after birth. The MSG-treated mice became obese after 4 weeks of age. According to patterns of weight gain compared with those in the control mice, the visceral organs in the MSG-treated mice were classified into three groups as follows: The first group of organs (heart, lungs, spleen, pancreas, kidneys, testes, brain and submandibular glands) remained absolutely lower in weight throughout their growth. The second group of organs (liver and stomach) was low in weight until 12 weeks of age, but became identical to that of the control mice after 16 weeks of age. The third group of organs (epididymal fat, small intestine and colon) showed lower weight until 4 weeks of age and were significantly heavier than those in the control mice after 8 weeks of age. The heart in the first group of organs apparently had hypertrophic muscle cells after 8 weeks of age and became significantly hypoplastic due to decreased cell production as was revealed by the continuous suppression of mitotic activity and DNA synthesis by [3H]thymidine autoradiography. The liver in the second group of organs became significantly hypoplastic due to decreased cell production and showed the same weight with the control mice due to the development of fatty liver. The small intestine in the third group of organs became hypoplastic due to decreased cell production in the crypts until 4 weeks of age, and became hypertrophic and hyperplastic by the acceleration of cell production in the crypts from 4 to 8 weeks of age. From these findings, in the MSG-treated mice with specific growth patterns of visceral organs, it is suggested that low energy expenditure results in a relatively excessive energy supply and leads to obesity, because most of the important organs with major physiological functions became hypoplastic. Moreover, it seems that hypertrophy and hyperplasia of the intestine suggest a possible acceleration of the absorptive function.
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PMID:Morphological and cell proliferative study on the growth of visceral organs in monosodium L-glutamate-treated obese mice. 380 54

In vitro experiments using both primary fetal hepatocyle cultures and adipoblast cultures have demonstrated that the presence of the fa gene is associated with decreased synthetic capacity, when compared to wild-type cultures. These results are in contrast to the elevated lipogensis and lipoprotein-lipase activities found in vivo in young adult obses (fafa) Zucker rats compared to their lean littermates. These studies used adipoblast cultures to address three possible explanations for these in vitro-in vivo differences: 1) FaFa and fafa adipoblast cultures represent different cell populations with intrinsically different abilities to differentiate, ie, to lipid-fill. 2) The decreased synthetic capacities in fafa vs FaFa adipoblast cultures are specific to cultures derived from the epididymal pad. 3) Cultured adipoblasts produce factor(s) that affect adipoblast differentiation in vitro. Results indicate that 1) the rate of differentiation is slower in fafa than in FaFa adipoblasts 2) there are depot-related differences in lipid metabolism, but these differences do not negate the in vitro association between the fa gene and decreased synthetic capacity and 3) FaFa epididymal-derived adipoblasts produce a factor(s) that affects inguinal-derived adipoblast differentiation and/or growth in vitro. Thus it is important to take both the site of cell origin and culture conditions into consideration when using in vitro systems as an approach to understanding complex in vivo disorders, such as obesity in the Zucker fafa rat.
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PMID:Adipoblasts from the Zucker fafa rat. 384 Jul 74

Mature male Sprague-Dawley rats fed a powdered Purina Chow diet containing corn oil and condensed milk (CM) were compared to rats fed a Purina Chow diet (control). CM rats gained more weight and consumed more calories over a 73-day period than the control rats. The increased weight gain and body fat in CM rats was accompanied by increased cell number in retroperitoneal and inguinal but not epididymal fat pads while cell size was unchanged in all three pads. After obesity had developed there was an increase in insulin levels, lipolysis, hepatic fatty acid synthesis, and fatty acid oxidation. While CM rats demonstrated hyperinsulinemia and hyperglycerolemia, they maintained normal glucagon and glucose levels. They demonstrated higher rates of fatty acid synthesis in isolated hepatocytes but not in vivo, suggesting that a greater potential for fatty acid synthesis in CM rats was masked in vivo by the inhibitory action of dietary lipids. Beta-oxidation of (1-14C) palmitate in vivo and in vitro, and in vivo ketogenesis were greater in CM than in chow fed rats. These studies demonstrate that, after the development of obesity, CM rats, like genetically obese Zucker rats, are hyperinsulinemic and have elevated levels of fatty acid synthesis. However, unlike obese Zucker rats, CM rats displayed an increase in beta-oxidation. These studies suggest that increased insulin levels and hepatic fatty acid synthesis may contribute to dietary obesity (as they do to genetic obesity), whereas increased fatty acid oxidation in dietary obesity may be a compensatory response to maintain a lower body weight.
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PMID:Changes in lipid metabolism in diet-induced obesity. 388 41

The activity of lipoprotein lipase (LPL) was studied in interscapilar brown adipose tissue (BAT), epididymal white adipose tissue (WAT) and in the heart of lean and obese adult Zucker rats maintained at 22 degrees C or adapted to cold (10 degrees C). In WAT the specific activity per gram of tissue was lower in obese than in lean rats but the total activity within the tissue was three-fold higher. Cold acclimation did not modify total activity in either lean or obese rats. In BAT, but not in the heart, both specific and total activities were lower in obese than in lean animals. They were enhanced in both tissues following cold acclimation. Six-hour fasting led to a decrease in specific activity in WAT of lean rats but had no effect in obese animals; an increase was observed in BAT and heart of both genotypes. Insulin administration has no effect on activities in WAT in either 22 or 10 degrees C adapted obese rats. Norepinephrine administration stimulates LPL activity in BAT and heart of all groups. It is concluded that the lack of development of obesity previously observed in obese rats following cold acclimation is not due to a decreased capacity of lipid uptake by WAT. It might in part be due to an increased lipid oxidation in BAT.
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PMID:Effects of cold acclimation on the activity of lipoprotein lipase in adipose tissues of genetically obese Zucker rats. 389 31


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