The effects of intragastric injections of various substances on subsequent bar-pressing.

Smith, Moncrieff H.; Duffy, Michael

doi:10.1037/h0040160

Cited by 52 publications

(18 citation statements)

References 9 publications

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“…For example, consumption of a large volume meal with a low nutrient/energy density can decrease subsequent food intake over a limited PERIPHERAL SIGNALS AND ENERGY HOMEOSTASIS period of time, usually 1 day. However, when the energy density of food is decreased over a more prolonged period of time by dilution with non-nutritive ingredients and the macronutrient proportions of the diets remain the same, more frequent but smaller meals are consumed such that energy intake remains relatively constant (47,48). Thus, volume detection does not appear to have a major role in the long-term regulation of energy balance and body adiposity (reviewed in Ref.…”

Section: Signals From the Gi Tractmentioning

confidence: 99%

Peripheral Signals Conveying Metabolic Information to the Brain: Short-Term and Long-Term Regulation of Food Intake and Energy Homeostasis

Havel

2001

Exp Biol Med (Maywood)

399

259

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Numerous peripheral signals contribute to the regulation of food intake and energy homeostasis. Mechano-and chemoreceptors signaling the presence and energy density of food in the gastrointestinal (GI) tract contribute to satiety in the immediate postprandial period. Changes in circulating glucose concentrations appear to elicit meal initiation and termination by regulating activity of specific hypothalamic neurons that respond to glucose. Other nutrients (e.g., amino acids and fatty acids) and GI peptide hormones, most notably cholecystokinin, are also involved in short-term regulation of food intake. However, the energy density of food and short-term hormonal signals by themselves are insufficient to produce sustained changes in energy balance and body adiposity. Rather, these signals interact with long-term regulators (i.e., insulin, leptin, and possibly the orexigenic gastric peptide, ghrelin) to maintain energy homeostasis. Insulin and leptin are transported into the brain where they modulate expression of hypothalamic neuropeptides known to regulate feeding behavior and body weight. Circulating insulin and leptin concentrations are proportional to body fat content; however, their secretion and circulating levels are also influenced by recent energy intake and dietary macronutrient content. Insulin and leptin concentrations decrease during fasting and energy-restricted diets, independent of body fat changes, ensuring that feeding is triggered before body energy stores become depleted. Dietary fat and fructose do not stimulate insulin secretion and leptin production. Therefore, attenuated production of insulin and leptin could lead to increased energy intake and contribute to weight gain and obesity during long-term consumption of diets high in fat and/or fructose. Transcription of the leptin gene and leptin secretion are regulated by insulin-mediated increases of glucose utilization and appear to require aerobic metabolism of glucose beyond pyruvate. Other adipocyte-derived hormones and proteins that regulate adipocyte metabolism, including acylation stimulating protein, adiponectin, diacylglycerol acyltransferase, and perilipin, are likely to have significant roles in energy homeostasis.

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Section: Signals From the Gi Tractmentioning

confidence: 99%

Peripheral Signals Conveying Metabolic Information to the Brain: Short-Term and Long-Term Regulation of Food Intake and Energy Homeostasis

Havel

2001

Exp Biol Med (Maywood)

399

259

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“…In agreement with Kohn, these authors also stated that it was exceedingly unlikely that the results were due to the effects of digestion and absorption of the load. Smith & Duffy (1955) showed that whereas stomach loading of 10 ml of isotonic saline had no effect upon bar pressing for food, loads of 30% sucrose depressed instrumental responding. Three load volumes of sucrose were used (4, 7, and 10 ml), and a direct relationship was observed between size of stomach load and degree of inhibition of operant responding for food.…”

Section: Discussionmentioning

confidence: 98%

“…The gastric catheter and fistula techniques of stomach loading have been widely used in the study of food intake regulation (Kohn, 1951;Berkun, Kessen, & Miller, 1952;Smith & Duffy, 1955). The typical experimental paradigm consists of a stomach loading session using a gastric catheter or fistula, and a subsequent test session to observe the effect on such variables as food intake, water intake, bar pressing for food or water.…”

mentioning

confidence: 99%

Tube feeding: Intestinal factors in gastric loading

Balagura

Fibiger

1968

Psychon Sci

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An experiment was performed to measure stomach retention as a function of stomach load in 60 female albino rats. Each group (N = 10) was loaded with 5, 12, or 25 ml of either isotonic saline or Metrecal. It was found that stomach retention was equal to stomach load only in the 5 ml condition. When greater loads were used, an increasing proportion of the loads passed into the intestine. Intestinal factors in the short term regulation of eating are stressed.

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“…Thus Japanese quail respond to dietary dilution by increasing their intake initially by increasing meal frequency and latterly (through changes in gut dimensions) by increasing meal length and size (Savory and Gentle, 1976;Savory, 1980). Thus, injections of kaolin into the stomach of rats has been shown to depress subsequent intake (Smith, Pool and Weinberg, 1962) whereas bar-pressing has been shown to be without effect (Smith and Duffy, 1955). Owen and Ridgman, 1968).…”

Section: Discussionmentioning

confidence: 99%

Measuring hunger in the pig using operant conditioning: the effect of dietary bulk

et al. 1989

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Operant conditioning was used to measure the effect on the feeding motivation (hunger) of pigs of diluting nutrient restricted food allowances with straw. Twelve Large White x Landrace boars were maintained in individual pens where they received their daily food allowance. Prior to the experiment, the boars were conditioned in separate rooms to press a panel so as to receive small rewards of food. The effect of diluting meal with straw on panel pressing was investigated in two trials. In trial 1, the boars were allocated to the following treatments: high (H) (3-5 of maintenance (A/)), low (L) (1-5 M) and low/straw (LS) (1-5 M + 0-15 times the dry weight of meal as chopped straw). This dilution increased the food volume by proportionately 0-29. Operant response rates were measured in six 1-h tests in each of two periods at the start (days 3 to 10, period 1) and at the end (days 20 to 28, period 2) of the 28-day experiment. In trial 2, nine of the above boars were allocated to the following treatments: high (H) (3-0 A/), low (L) (1-5 M) and low/straw (LS) (1-5 M + 0-30 the dry weight of meal as ground straw). This dilution increased the food volume by proportionately 0-75. Operant response rates were measured as above between days 10 to 17, following a 9-day adjustment period to the new regimes.In both trials, operant response rate was strongly affected by treatment. Overall in trial 1, animals on the H treatment made few responses (mean 60 responses per session), animals on the L treatment made significantly more responses (mean 825, P < 0-001) and animals on the LS teatment significantly more responses yet again (1263, P < 0-05). This last difference was associated with the difficulty of the LS animals consuming all of the diluted diet during period 1. In trial 2, response rates were again higher on the L than on the H treatments. There was, however, no difference between the L and LS treatments (means: 60 v. 1035 v. 1200). Proportionately only 0-04 of the diet was refused during the period of testing.The present results show that short-term satiety arising from gut distension does not reduce the feeding motivation of animals on chronic nutrient restriction. This suggests that hunger will remain high in pigs on restricted food allowances, even when they have access to high fibre foods. This hunger will be a potential source of stress, particularly in housing systems involving physical restraint such as tether stalls.

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The effects of intragastric injections of various substances on subsequent bar-pressing.

Cited by 52 publications

References 9 publications

Peripheral Signals Conveying Metabolic Information to the Brain: Short-Term and Long-Term Regulation of Food Intake and Energy Homeostasis

Peripheral Signals Conveying Metabolic Information to the Brain: Short-Term and Long-Term Regulation of Food Intake and Energy Homeostasis

Tube feeding: Intestinal factors in gastric loading

Measuring hunger in the pig using operant conditioning: the effect of dietary bulk

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