Cholecystokinin persistently suppresses meal size but not food intake in free-feeding rats

1984 ◽  
Vol 246 (5) ◽  
pp. R776-R787 ◽  
Author(s):  
D. B. West ◽  
D. Fey ◽  
S. C. Woods
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Physiological Saline ◽  
Meal Size ◽  
Base Line ◽  
Drinking Patterns ◽  
Daily Food ◽  
Food And Water Intake ◽  
Dramatic Shift ◽  
Free Feeding

Food and water intake of free-feeding rats with indwelling intraperitoneal catheters connected to infusion pumps was continuously monitored and recorded by a microcomputer-based data acquisition system. Initially, at the start of every spontaneous meal for 4 days, each rat was infused with 0.27 ml of physiological saline. Saline infusion did not affect any feeding or drinking patterns, and the rate of weight gain remained unchanged. For 6 subsequent days, the octapeptide of cholecystokinin (CCK-8, 1.1 micrograms/meal) dissolved in physiological saline was infused at the onset of each meal. CCK-8 infusion caused a dramatic shift of patterns of food intake. Average meal size was reduced by at least 44%, whereas daily meal number increased by 162% or more for all 6 days of CCK-8 infusion. Total daily food intake recovered to predrug levels by the 4th day of CCK-8 infusion, primarily due to increased feeding frequency. Average body weight dropped by 12.4 g on the 1st day of CCK infusion, but over the following 5 days the growth rate was not different from the base-line predrug rate. With discontinuation of CCK-8 infusion all meal patterns returned rapidly to normal and body weight immediately recovered.

Feeding behavior in monkeys with and without lesions of the hypothalamus

1976 ◽  
Vol 230 (3) ◽  
pp. 818-830 ◽  
Author(s):  
CL Hamilton ◽  
PJ Ciaccia ◽  
DO Lewis
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Water Intake ◽  
Arcuate Nucleus ◽  
Serum Insulin ◽  
Hormone Release ◽  
Hypothalamic Lesions ◽  
Feeding Efficiency ◽  
Daily Food ◽  
Food And Water Intake

In monkeys (Macaca mulatta) without hypothalamic lesions, food intake was found to increase with increasing age and body weight; however, food intake per kilogram body weight showed a decline over the same period of time. As the animals became older, the amount of food intake converted to body weight decreased dramatically (feeding efficiency). Water intake was shown to be closely coupled to food intake. Both daily food and water-intake data were highly reliable over a period of years. Monkeys with ventromedial hypothalamic lesions exhibited hyperphagia and increased feeding-efficiency ratios and eventual obesity. The obese animals developed symptoms of diabetes mellitus. Animals with lesions restricted primarily to the arcuate nucleus showed no hyperphagia but increased feeding efficiency. These animals exhibited decreased growth hormone release and a transitory elevation of serum insulin.

Acute activation of ERα decreases food intake, meal size, and body weight in ovariectomized rats

2007 ◽  
Vol 293 (6) ◽  
pp. R2194-R2201 ◽  
Author(s):  
Jessica Santollo ◽  
Mathew D. Wiley ◽  
Lisa A. Eckel
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Dose Range ◽  
Meal Size ◽  
Ovariectomized Rats ◽  
Acute Administration ◽  
Daily Food Intake ◽  
Ovx Rats ◽  
Daily Food ◽  
Anorexigenic Effect

Estradiol exerts many of its actions by coupling with two nuclear estrogen receptor (ER) proteins, ERα, and ERβ.While the acute, anorexigenic effect of estradiol appears to involve such a mechanism, the relative contributions of ERα and ERβ are equivocal. To address this problem, food intake was monitored in ovariectomized (OVX) rats following acute administration of a selective ERα agonist (4,4′,4′′-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol, PPT; dose range = 0–200 μg), a selective ERβ agonist (2,3-bis(4-hydroxyphenyl)-propionitrile, DPN; dose range = 0–600 μg), and a physiological (4 μg) dose of estradiol benzoate (EB). While PPT-treated rats displayed dose-dependent decreases in daily food intake and body weight, neither of these measures was influenced by any dose of DPN. In addition, DPN failed to modulate the anorexigenic effect of PPT when the two ER agonists were coadministered. Meal pattern analysis revealed that the anorexigenic effect of 75 μg PPT (a dose of PPT that produced a similar decrease in daily food intake as 4 μg EB) was mediated by a decrease in meal size, not meal number. Thus, PPT, like EB and endogenous estradiol, decreases food intake by selectively affecting the controls of meal size. The finding that acute administration of 75 μg PPT failed to induce a conditioned taste aversion suggests that the anorexigenic effect of this dose of PPT is not secondary to malaise. Taken together, our findings demonstrate that selective activation of ERα decreases food intake, body weight, and meal size in the ovariectomized rat.

scholarly journals Body composition and appetite: fat-free mass (but not fat mass or BMI) is positively associated with self-determined meal size and daily energy intake in humans

2011 ◽  
Vol 107 (3) ◽  
pp. 445-449 ◽  
Author(s):  
John E. Blundell ◽  
Phillipa Caudwell ◽  
Catherine Gibbons ◽  
Mark Hopkins ◽  
Erik Näslund ◽  
...  
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Food Intake ◽  
Energy Intake ◽  
Fat Mass ◽  
Meal Size ◽  
Fat Free Mass ◽  
Daily Energy Intake ◽  
Molecular Control ◽  
Daily Energy

The idea of body weight regulation implies that a biological mechanism exerts control over energy expenditure and food intake. This is a central tenet of energy homeostasis. However, the source and identity of the controlling mechanism have not been identified, although it is often presumed to be some long-acting signal related to body fat, such as leptin. Using a comprehensive experimental platform, we have investigated the relationship between biological and behavioural variables in two separate studies over a 12-week intervention period in obese adults (totaln92). All variables have been measured objectively and with a similar degree of scientific control and precision, including anthropometric factors, body composition, RMR and accumulative energy consumed at individual meals across the whole day. Results showed that meal size and daily energy intake (EI) were significantly correlated with fat-free mass (FFM,Pvalues < 0·02–0·05) but not with fat mass (FM) or BMI (Pvalues 0·11–0·45) (study 1,n58). In study 2 (n34), FFM (but not FM or BMI) predicted meal size and daily EI under two distinct dietary conditions (high-fat and low-fat). These data appear to indicate that, under these circumstances, some signal associated with lean mass (but not FM) exerts a determining effect over self-selected food consumption. This signal may be postulated to interact with a separate class of signals generated by FM. This finding may have implications for investigations of the molecular control of food intake and body weight and for the management of obesity.

Effects of intermittent intraperitoneal infusion of salmon calcitonin on food intake and adiposity in obese rats

2007 ◽  
Vol 293 (5) ◽  
pp. R1798-R1808 ◽  
Author(s):  
Prasanth K. Chelikani ◽  
Alvin C. Haver ◽  
Roger D. Reidelberger
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Salmon Calcitonin ◽  
Chronic Administration ◽  
Inhibitory Effect ◽  
Free Access ◽  
Daily Food Intake ◽  
Intraperitoneal Infusion ◽  
Daily Food ◽  
Obese Rats

Chronic administration of anorexigenic substances to experimental animals by injections or continuous infusion typically produces no effect or a transient reduction in daily food intake and body weight. Our aim was to identify an intermittent dosing strategy for intraperitoneal infusion of salmon calcitonin (sCT), a homolog of amylin that produces a sustained 25–35% reduction in daily food intake and adiposity in diet-induced obese rats. Rats (649 ± 10 g body wt, 27 ± 1% body fat), with intraperitoneal catheters tethered to infusion swivels, had free access to a 45% fat diet. Food intake, body weight, and adiposity during the 7-wk test period were relatively stable in the vehicle-treated rats ( n = 16). None of 10 sCT dosing regimens administered in succession to a second group of rats ( n = 18) produced a sustained 25–35% reduction in daily food intake for >5 days, although body weight and adiposity were reduced by 9% (587 ± 12 vs. 651 ± 14 g) and 22% (20.6 ± 1.2 vs. 26.5 ± 1.1%), respectively, across the 7-wk period. The declining inhibitory effect of sCT on daily food intake with the 6-h interinfusion interval appeared to be due in part to an increase in food intake between infusions. The declining inhibitory effect of sCT on daily food intake with the 2- to 3-h interinfusion interval suggested possible receptor downregulation and tolerance to frequent sCT administration; however, food intake increased dramatically when sCT was discontinued for 1 day after apparent loss of treatment efficacy. Together, these results demonstrate the activation of a potent homeostatic response to increase food intake when sCT reduces food intake and energy reserves in diet-induced obese rats.

Intermittent intraperitoneal infusion of peptide YY(3-36) reduces daily food intake and adiposity in obese rats

2007 ◽  
Vol 293 (1) ◽  
pp. R39-R46 ◽  
Author(s):  
Prasanth K. Chelikani ◽  
Alvin C. Haver ◽  
Roger D. Reidelberger
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Peptide Yy ◽  
Caloric Intake ◽  
Daily Food Intake ◽  
Daily Caloric Intake ◽  
Intraperitoneal Infusion ◽  
Daily Food ◽  
Sustained Reduction ◽  
Obese Rats

Peptide YY(3-36) [PYY(3-36)] is a gut-brain peptide that decreases food intake when administered by intravenous infusion to lean and obese humans and rats. However, chronic administration of PYY(3-36) by osmotic minipump to lean and obese rodents produces only a transient reduction in daily food intake and weight gain. It has recently been shown that 1-h intravenous infusions of PYY(3-36) every other hour for 10 days produced a sustained reduction in daily food intake, body weight, and adiposity in lean rats. Here, we determined whether intermittent delivery of PYY(3-36) can produce a similar response in diet-induced obese rats. During a 21-day period, obese rats (body fat >25%) received twice daily intraperitoneal infusion of vehicle ( n = 18) or PYY(3-36) ( n = 24) during hours 1–3 and 7–9 of the dark period. Rats had free access to both a 45% fat solid diet and a 29% fat liquid diet; intakes were determined from continuous computer recording of changes in food container weights. To sustain a 15–25% reduction in daily caloric intake, the initial PYY(3-36) dose of 30 pmol·kg−1·min−1 was reduced to 10 pmol·kg−1·min−1 on day 10 and then increased to 17 pmol·kg−1·min−1 on day 13. This dosing strategy produced a sustained reduction in daily caloric intake of 11–32% and prevented body weight gain (8 ± 6 vs. 51 ± 11 g) and fat deposition (4.4 ± 7.6 vs. 41.0 ± 12.8 g). These results indicate that intermittent intraperitoneal infusion of PYY(3-36) can produce a sustained reduction in food intake and adiposity in diet-induced obese rodents consuming palatable high-fat foods.

Central administration of metformin into the third ventricle of C57BL/6 mice decreases meal size and number and activates hypothalamic S6 kinase

2013 ◽  
Vol 305 (5) ◽  
pp. R499-R505 ◽  
Author(s):  
Hyun-Ju Kim ◽  
Eun-Young Park ◽  
Mi-Jeong Oh ◽  
Sung-Soo Park ◽  
Kyung-Ho Shin ◽  
...  
Keyword(s):  
Body Weight ◽  
Energy Balance ◽  
Food Intake ◽  
Third Ventricle ◽  
Meal Size ◽  
Dependent Manner ◽  
Central Administration ◽  
Mediobasal Hypothalamus ◽  
S6 Kinase ◽  
The Third

Administration of metformin is known to reduce both body weight and food intake. Although the hypothalamus is recognized as a critical regulator of energy balance and body weight, there is currently no evidence for an effect of metformin in the hypothalamus. Therefore, we sought to determine the central action of metformin on energy balance and body weight, as well as its potential involvement with key hypothalamic energy sensors, including adenosine monophosphate-activated protein kinase (AMPK) and S6 kinase (S6K). We used meal pattern analysis and a conditioned taste aversion (CTA) test and measured energy expenditure in C56BL/6 mice administered metformin (0, 7.5, 15, or 30 μg) into the third ventricle (I3V). Furthermore, we I3V-administered either control or metformin (30 μg) and compared the phosphorylation of AMPK and S6K in the mouse mediobasal hypothalamus. Compared with the control, I3V administration of metformin decreased body weight and food intake in a dose-dependent manner and did not result in CTA. Furthermore, the reduction in food intake induced by I3V administration of metformin was accomplished by decreases in both nocturnal meal size and number. Compared with the control, I3V administration of metformin significantly increased phosphorylation of S6K at Thr389 and AMPK at Ser485/491 in the mediobasal hypothalamus, while AMPK phosphorylation at Thr172 was not significantly altered. Moreover, I3V rapamycin pretreatment restored the metformin-induced anorexia and weight loss. These results suggest that the reduction in food intake induced by the central administration of metformin in the mice may be mediated by activation of S6K pathway.

scholarly journals Daily, intermittent intravenous infusion of peptide YY(3-36) reduces daily food intake and adiposity in rats

2006 ◽  
Vol 290 (2) ◽  
pp. R298-R305 ◽  
Author(s):  
Prasanth K. Chelikani ◽  
Alvin C. Haver ◽  
Joseph R. Reeve ◽  
David A. Keire ◽  
Roger D. Reidelberger
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Intravenous Infusion ◽  
Peptide Yy ◽  
Subcutaneous Administration ◽  
Chronic Administration ◽  
Daily Food Intake ◽  
Daily Food ◽  
Sustained Reduction ◽  
Gut Hormone

The gut hormone peptide YY(3-36) [PYY(3-36)] decreases food intake when administered by intravenous infusion to lean and obese humans and rats. Whether chronic administration of PYY(3-36) produces a sustained reduction in food intake and adiposity is the subject of intense debate. Batterham et al. (R. L. Batterham, M. A. Cowley, C. J. Small, H. Herzog, M. A. Cohen, C. L. Dakin, A. M. Wren, A. E. Brynes, M. J. Low, M. A. Ghatei, R. D. Cone, and S. R. Bloom. Nature 418: 650–654, 2002) first reported that PYY(3-36) reduces food intake and weight gain in rats when injected into the peritoneal cavity twice daily for 7 days. Numerous laboratories have failed to confirm that daily injections of PYY(3-36) decrease body weight. Continuous subcutaneous administration of PYY(3-36) by osmotic minipump has been reported to reduce daily food intake in rodents but only during the first 3–4 days of administration. Here we show the effects of different daily patterns of intravenous infusion of PYY(3-36) on food intake, body weight, and adiposity in rats tethered via infusion swivels to computer-controlled pumps. Measurement of food bowl weight recorded by computer every 20 s permitted daily assessment of the instantaneous effects of PYY(3-36) administration on food intake and meal patterns. One-hour intravenous infusions of PYY(3-36) at 30 pmol·kg−1·min−1 every other hour for 10 days produced a sustained reduction in daily food intake of ∼20% and decreased body weight and adiposity by 7 and 35%, respectively. Thus dosage pattern is critical for producing a sustained effect of PYY(3-36) on food intake and adiposity.

scholarly journals Pancreatic signals controlling food intake; insulin, glucagon and amylin

2006 ◽  
Vol 361 (1471) ◽  
pp. 1219-1235 ◽  
Author(s):  
Stephen C Woods ◽  
Thomas A Lutz ◽  
Nori Geary ◽  
Wolfgang Langhans
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Energy Homeostasis ◽  
Endocrine Pancreas ◽  
Situational Factors ◽  
Meal Size ◽  
Vagus Nerves ◽  
Social Emotional ◽  
Short Term ◽  
The Brain

The control of food intake and body weight by the brain relies upon the detection and integration of signals reflecting energy stores and fluxes, and their interaction with many different inputs related to food palatability and gastrointestinal handling as well as social, emotional, circadian, habitual and other situational factors. This review focuses upon the role of hormones secreted by the endocrine pancreas: hormones, which individually and collectively influence food intake, with an emphasis upon insulin, glucagon and amylin. Insulin and amylin are co-secreted by B-cells and provide a signal that reflects both circulating energy in the form of glucose and stored energy in the form of visceral adipose tissue. Insulin acts directly at the liver to suppress the synthesis and secretion of glucose, and some plasma insulin is transported into the brain and especially the mediobasal hypothalamus where it elicits a net catabolic response, particularly reduced food intake and loss of body weight. Amylin reduces meal size by stimulating neurons in the hindbrain, and there is evidence that amylin additionally functions as an adiposity signal controlling body weight as well as meal size. Glucagon is secreted from A-cells and increases glucose secretion from the liver. Glucagon acts in the liver to reduce meal size, the signal being relayed to the brain via the vagus nerves. To summarize, hormones of the endocrine pancreas are collectively at the crossroads of many aspects of energy homeostasis. Glucagon and amylin act in the short term to reduce meal size, and insulin sensitizes the brain to short-term meal-generated satiety signals; and insulin and perhaps amylin as well act over longer intervals to modulate the amount of fat maintained and defended by the brain. Hormones of the endocrine pancreas interact with receptors at many points along the gut–brain axis, from the liver to the sensory vagus nerve to the hindbrain to the hypothalamus; and their signals are conveyed both neurally and humorally. Finally, their actions include gastrointestinal and metabolic as well as behavioural effects.

Changes in the food intake and body weight of protein-malnourished rats infected with Nippostrongylus brasiliensis (Nematoda)

Parasitology ◽  
1981 ◽  
Vol 82 (1) ◽  
pp. 23-38 ◽  
Author(s):  
D. W. T. Crompton ◽  
D. E. Walters ◽  
Susan Arnold
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Infected Group ◽  
Nippostrongylus Brasiliensis ◽  
Initial Weight ◽  
Daily Food Intake ◽  
Young Rats ◽  
Daily Food ◽  
Long Duration ◽  
Ad Libitum

SUMMARYThe daily food intake and related changes in body weight were measured in young rats which were fed on synthetic diets containing 1% (3 experiments), 2% (4 experiments) and 20% (1 experiment) casein respectively. Some rats were infected with Nippostrongylus brasiliensis and allowed to feed ad libitum, some remained uninfected and were allowed to feed ad libitum while others, which were matched by initial weight with rats from the infected group, remained uninfected and were given only the same amount of food as that consumed during the previous 24 h by their infected partners. No significant differences were detected between the rats before the start of the infection. Thereafter, the food intake of the infected undernourished rats was usually found to be significantly lower and the loss of body weight significantly greater than those of the uninfected rats. In infection periods of relatively long duration, the pair-fed uninfected rats did not lose as much weight as their infected partners even though their food intake (1% and 2% casein) was the same. Although the food intake, and consequently the weight, of infected rats fed on the diet containing 20% casein were significantly less than in their uninfected partners, no significant differences were observed between the weights of the infected and pair-fed rats fed on this diet.

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