Changes in body composition attendant on force feeding

Cohn, Clarence; Joseph, Dorothy

doi:10.1152/ajplegacy.1959.196.5.965

Cited by 190 publications

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“…When groups of postweaning immature male rats were pair-fed equal amounts of food, one group fed ad libitum and the other force-fed several meals daily ("meal-fed"), animals in the latter group became obese adults (6,7). In contrast to these reports on "meal-fed" animals, the presently studied feed-restricted rats are proportionately leaner at puberty than their well fed controls.…”

mentioning

confidence: 63%

Pubertal Food Intake and Body Length, Weight, and Composition in the Feed-Restricted Female Rat: Comparison with Well Fed Animals

Wilen

Naftolin

1978

Pediatr Res

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Summarymaturation earlier but at an average body weight which is not Individual pubertal age, food intake, and body length, weight, and composition were determined by direct measurements in 28 feed-restricted female rats studied from birth to first estrus, and were compared to well fed controls (39). The average birth (6.87 0.19 g) and weaning (49.39 * 0.72 g) weights of the 1 3 early maturing feed-restricted rats did not differ significantly from those of the 13 late maturers (6.72 2 0.31 g and 49.96 * g, respectively). Mean values for all pubertal measurements are included in Table 1. F i t estrus was simultaneous with vaginal opening in nine (69%) of early and two (15%) of the late maturing feed-restricted rats. At first estrus, the late maturing, feed-restricted animals were heavier, longer (Fig. I), and had attained a greater quantity of total body fat, protein, and water than the early maturers. Furthermore, at first estrus the late maturing feed-restricted rats had acquired a greater proportion of body water than the early maturers; however, both groups had attained the same proportion of body protein (Fig. 2). Although early and late maturing feed-restricted rats were eating the same amounts of food at the time of vaginal opening and at f i t estrus, late maturing rats consumed less food per 100 g body wt than did early maturers. The average birth (6.99 2 0.74 g) and weaning (49.7 2 0.74 g) weights of all 29 well fed rats did not differ from those of the feed-restricted group --(6.76 * 0.17 g and 48.95 0.6 g, respectively). F i t estrus was simultaneous with vaginal opening in 20 (69%) of the well fed and 13 (46%) of the feed-restricted rats. At first estrus average body weights and nose-rump length were the same for well fed and feed-restricted groups. Mean ages at vaginal opening and at first estrus in the feed-restricted animals were, however, greater. Absolute amount and percentage of body water did not, on the average, diier in the two groups; however, the feed-restricted animals attained less fat, were proportionately leaner, acquired a greater quantity and proportion of protein, and consumed less food. SpeculationAs seen within the previously studied well fed control group, differences in food intake and somatic development in individual feed-restricted rats at rust estrus suggest that the attainment of a constant body weight, level of fat, or food intake may not be essential for the onset of puberty. Our findings in rats at first estrus suggest that although dietary manipulation may effect a change in the overall proportion of body fat and protein, within a homogeneous group of rats at first estrus there is a percentage of body protein which remains the same with increasing age at sexual maturation.Previous studies have shown that well nourished female animals (1 0,25,27,28,36,37) and humans (1 3) attain sexual 26 statistically different from that reached b; undernourished maturing individuals. Malnourished girls, however, are taller at menarche than their well fed counterparts (13). Well fed fe...

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confidence: 63%

Pubertal Food Intake and Body Length, Weight, and Composition in the Feed-Restricted Female Rat: Comparison with Well Fed Animals

Wilen

Naftolin

1978

Pediatr Res

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“…Thus, it could be said that meal feeding may enhance lipid metabolism of adipose tissue in rats, involving lipolysis as well as lipogenesis which has been frequently reported. This seems to give a new idea for realizing the discrepancy that, although the increased body fat accumulation in meal-fed rats has been reported by pioneer workers (41)(42)(43) in this interesting field of nutrition, many workers (20,(44)(45)(46) …”

Section: Discussionmentioning

confidence: 95%

Diurnal changes in lipolytic activity of isolated fat cells and their increased responsiveness to epinephrine and theophylline with meal feeding in rats.

Suzuki

Shimomura

Satoh

1983

Journal of Nutritional Science and Vitaminology, J Nutr Sci Vit

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SummaryDiurnal changes in glycogen stores of adipose tissues and in vitro lipolytic activity of isolated epididymal fat cells, and their lipolytic responsiveness to epinephrine and theophylline were examined in rats adapted to a 2-h daily meal feeding (20.00-22.00h; darkness between 20.00-08.00h) for 3 weeks and in control rats fed ad libitum. The fat cells from both groups of animals showed the peak of lipolytic activity at the mid-dark period (03.00h), but the peak values and the average values at 6 or 7 time points examined within the 24-h feeding cycle were significantly higher (p<0.025) in meal-fed rats. Basal, epinephrine-stimulated, and epinephrine-induced lipolysis of fat cells from control rats showed diurnal changes, and the rhythms and their amplitude were affected by meal feeding. Changes in lipolytic activity of fat cells did not seem to relate directly to those of glycogen stores in adipose tissue. The over-all 24-h means of lipolytic activity of fat cells were significantly increased (p<0.001) with meal feeding. Mean cell size of epididymal fat pads was significantly smaller (p<0.001) in meal-fed rats, but lipolytic responsive ness to the graded concentrations of epinephrine and theophylline in the incubation medium was significantly greater (p<0.001) in meal-fed rats than in rats fed ad libitum. Thus, these findings suggest that lipolytic activity of the CAMP-hormone sensitive lipase system in fat cells might be increased with meal feeding in rats. Furthermore, the present results may give a new idea to consider the discrepancy that many workers have not been able to observe the increase in body fat deposition with meal feeding,

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“…Ss were then forced to gain weight by tubing a special diet (Cohn & Joseph, 1959) into their stomachs twice daily. The individual stomach loads were started at 5 cc and increased daily to 15 cc.…”

Section: Methodsmentioning

confidence: 99%

Lateral hypothalamic self-stimulation: Effect of excess body weight

Macneil

1974

Psychobiology

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Self-stimulation in the lateral hypothalamus was measured in rats made obese by force-feeding a liquid diet. Mean self-stimulation rate at the obese weight was significantly less than the mean self-stimulation rate at normal weight levels. This result is consistent with the view that a factor correlated with obesity inhibits feeding by inhibiting lateral hypothalamic reward.Obesity inhibits feeding. Rats that have been forced to become obese, by force-feeding, insulin treatments, or lateral hypothalamic stimulation, will subsequently reduce their body weight by restricting their food intake (Cohn & Joseph, 1962;Hoebel & Teitelbaum, 1966; Steinbaum & Miller, 1965). Normal body weight is thereby regulated through changes in food intake.It is now known that an animal's state of hunger or satiety determines, in part, electrical self-stimulation in the lateral hypothalamus (LH). For instance, self-stimulation rate increases when an animal is deprived for 24 h (Margules & Olds, 1961), but decreases after intragastric or intravenous feeding, or when the stomach is distended with an intragastric balloon (Hoebel, 1968). Changes in self-stimulation rate also parallel changes in food intake when blood glucose is altered with injections of insulin or glucagon (Balagura & Hoebel, 1967). It was therefore predicted that self-stimulation in the LH would, like food intake, be depressed when an animal was overweight. To test this hypothesis, self-stimulation rate was measured daily in rats force-fed a liquid diet to increase their body weights above the normal level. METHOD SubjectsFive female albino rats, weighing between 250 and 320 g, were housed in individual cages and given free access to food (purina Laboratory Meal) and water. Ss were kept in a temperature-controlled room, where the lights were automatically programmed for a 12-h light-dark cycle. Each S was implanted with a prefabricated electrode assembly, as described by Hoebel (1964) . With this technique, 90% platinum-l0% iridium electrodes were chronically placed in the lateral hypothalamus of both sides of the brain. The coordinates with the top of the cortex level were: A, 6.0 mm; L, 2.0 mm; and D, 7.5 mm. A stainless steel wire was wrapped around the cranial screws and was left to protrude through the dental cement to serve as an indifferent electrode. ApparatusA Tektronix 161 pulse generator produced the electrical stimulation. The pulses were negative, 0.1 msec in duration, and occurred at a repetition rate of 100 pps. Stimulation was *This study is part of a PhD thesis submitted to the Department of Psycho!oiY. Princeton University. and was supported by PHS Grant MH08493 and NSF Grant GB8431 to Bartley G. Hoebel. 51 delivered to the rats through a constant current device and was continuously monitored with an oscilloscope.The experimental chamber (7 x 12 in.) consisted of four clear plastic walls, a response lever (Lehigh Valley No. 121-05), and a grid floor. An overhead mercury commutator prevented the stimulation leads to the rat from becoming entangled. A p...

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Changes in body composition attendant on force feeding

Cited by 190 publications

References 0 publications

Pubertal Food Intake and Body Length, Weight, and Composition in the Feed-Restricted Female Rat: Comparison with Well Fed Animals

Pubertal Food Intake and Body Length, Weight, and Composition in the Feed-Restricted Female Rat: Comparison with Well Fed Animals

Diurnal changes in lipolytic activity of isolated fat cells and their increased responsiveness to epinephrine and theophylline with meal feeding in rats.

Lateral hypothalamic self-stimulation: Effect of excess body weight

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