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Biomedical subjects

T R Houpt

Publications and source records attributed to T R Houpt.

At least 37 records · Page 2Linked to original sources
PubMed1983

The sites of action of cholecystokinin in decreasing meal size in pigs.

The synthetic octapeptide of cholecystokinin (CCK-8) was infused at the rate of 67 ng/kg-minute into the jugular vein, carotid artery, portal vein, gastric branch of the splenic artery, and aortic artery both craniad and caudad to the origins of the cranial mesenteric and coeliac arteries of 39 young female pigs. Jugular, carotid and cranial erotic infusions resulted in significant reduction of meal size respectively to 65, 67 and 71% of control meal size (p less than 0.05). Gastric artery infusion resulted in a significant increase of meal size to 122% of control meal size (p less than 0.05). Portal vein and caudal aortic artery infusions had no significant effects on meal size. The results were interpreted as indicating a major site of action of CCK in reducing meal size in the bed of the cranial mesenteric or coeliac arteries, but excluding the stomach and liver.

Animals↗
PubMed1983

Humoral and cardiovascular responses to feeding in pigs.

In young pigs, allowed to feed after various periods of food deprivation, the changes in plasma levels of insulin, glucose, and corticosteroids were measured. Food was presented in bowls or obtained by operant response. In pigs deprived of food for 17 h there was a marked rise in insulin from 15 +/- 1 to 91 +/- 10 microU/ml and glucose from 94 +/- 2 to 112 +/- 4 mg/dl when feeding began, while the corticosteroid levels were reduced from 48 +/- 8 to 29 +/- 9 ng/ml. Evidence for a cephalic phase of insulin secretion was seen in 17-h fasted pigs. In pigs fed ad libitum there were no significant changes in the levels of insulin, glucose, or corticosteroids. The changes observed in the 5-h fasted pigs were intermediate. No differences were seen between bowl-fed and operant pigs. Pressure transducers were surgically implanted in the carotid arteries of three pigs. When 17-h fasted pigs started to eat there was a marked rise of blood pressure from 114 +/- 3 to 147 +/- 5 mmHg and a similar increase was seen when satiated pigs drank milk.

Animals↗
PubMed1983

Duodenal osmoconcentration and food intake in pigs after ingestion of hypertonic nutrients.

Samples were taken from the duodenum of young pigs via indwelling catheters after ingestion of liquid meals. They had been deprived of feed and water overnight. Samples were taken every minute for 15 min and then at 20, 25, 30, 40, 50, and 60 min. After ingestion of hypertonic glucose solutions, duodenal osmolality rose rapidly to maximal levels within 10-15 min when osmoconcentrations were as follows: for 10% glucose, 480 mosmol/kg H2O; for 20%, 680; and for 40%, 1,200. After 5% glucose, osmolality was about 280 mosmol/kg H2O and did not change appreciably during the hour. Water ingestion caused a fall to 60 mosmol/kg H2O at 3 min and then a slow recovery. Ingestion of glucose-in-milk solutions gave similar but slightly higher values. When the glucose-in-water or -milk solutions were ingested just before a meal of feed pellets, meal size was depressed proportional to glucose concentration.

Animals↗
PubMed1983

The effect of gastric loads of sugars and amino acids on milk intake of suckling pigs.

A 3 h fast of suckling pigs less than a week of age decreased plasma glucose (P less than .005), but did not affect plasma protein, osmolality or hematocrit. After fasting, solutions (40 ml/kg body weight) of 5% glucose, 5% fructose, 5% xylose, 5% mannitol, 5% sorbitol, 2.5% leucine, 2.5% phenylalanine (50 ml/kg), .9% NaCl, 5% lactose, 5% sucrose and a 50% egg yolk-distilled water mixture were administered by stomach tube and the piglet then returned to the sow. Weight gain was used as a measure of sow's milk intake. Milk consumption during the first 3 h after fasting was lower (P less than .05) for pigs given glucose than for sham-loaded controls, but no differences were observed between glucose and mannitol or sorbitol for the same period. Mannitol and sorbitol were more effective than NaCl (P less than .01) in lowering consumption for the 3 h after loading. Also during the first hour after loading, xylose caused lower (P less than .001) food intake than glucose. Egg yolk suppressed intake in comparison to sham-loaded controls (P less than .05). D-phenylalanine suppressed intake more than L-phenylalanine (P less than .05), but no differences were observed between the D and L isomers of leucine.

Amino Acids↗
PubMed1981

Cholecystokinin and satiety in pigs.

Twenty-three pigs, 1-3 mo of age, were fitted variously with intraperitoneal, intrajugular, intraportal, and intraduodenal catheters. After a 4-h fast, porcine cholecystokinin (CCK), 5-40 Ivy dog units/kg body wt (IDU/kg); caerulein, 0.25-2 micrograms/kg; or the octapeptide of cholecystokinin (CCK-OP), 5-40 IDU/kg, was given parenterally; or 2-5% sodium oleate or 5% protein hydrolysate (5 ml/kg) was injected intraduodenally. Pelleted feed intake was then measured for 10 min. Food intake was depressed in a dose-related fashion in all instances as compared to after 0.9% NaCl control injections. For example, feed consumption following 5 and 40 IDU/kg of CCK intrajugularly was 84 +/- 2 and 6 +/- 4 (SE) %, respectively, of control intake. Intraportal infusion produced a greater depression of feeding. A conditioned taste aversion could not be formed to CCK, caerulein, or CCK-OP. Sodium oleate or protein hydrolysate, releasers of endogenous CCK, depressed feeding, and this satiety effect was attenuated when given with 0.5% tetracaine. The results support the hypothesis that CCK participates in rapid, presumably preabsorptive, satiety.

Anesthetics, Local↗
PubMed1979

Gastric emptying and cholecystokinin in the control of food intake in suckling rats.

The rate of gastric emptying was determined in three-day old suckling rats. The gastric loads were given by gavage, and, after from 5 to 100 min, emptying was determined by removing the stomach and weighing the contents. Results were expressed as percentage of load still remaining in the stomach at one hour. The gastric loads in increasing order of speed of emptying were 1.0 M Na acetate, heavy cream, 0.5 M NaCl, milk, corn oil, 0.15 M lactose, 0.3 M glucose, 0.15 M NaCl, acidic water, and water. The rate of emptying was compared to the effectiveness in previous experiments of the same gastric loads in depressing intake. There was no significant correlation between rate of gastric emptying of the loads and their effectiveness in producing satiety. The octapeptide of cholecystokinin (80 Ivy dog units or 2.7 micrograms/kg i.p.) significantly depressed intake (measured as weight gain) of suckling rats of 1 1/2 hours, but the same dose did not slow gastric emptying. These findings indicate that rate of gastric emptying does not determine satiety in the suckling rat.

Animals↗
PubMed1979

Preabsorptive intestinal satiety controls of food intake in pigs.

Pigs, 1--3 mo of age, weighing 5--80 kg, were fitted with duodenal, intraportal, or intrajugular catheters. After a 4-h fast, preloads were delivered to the duodenum, and food intake then measured for 10 min (no drinking water). Glucose (5--40%) and NaCl (0.9--6.5%) solutions were used as preloads (5 ml/kg body wt). Food intake expressed as percent control intake (Y) was depressed in proportion to preload concentration (X): for glucose, Y = 109 - 2X; for NaCl, Y = 107 - 13X. When expressed in osmoconcentration, glucose and NaCl preloads had nearly identical satiety effects. Preloads of 40% sorbitol depressed intake to 74% control. Intrathoracic vagotomy reduced the satiety effects of glucose and NaCl solutions by 50%. Tetracaine (0.5%) in the hypertonic preloads blocked 80% of the satiety effects of the glucose and NaCl preloads, but had no effect on sorbitol satiety effect. Injection of glucose or NaCl solutions into the portal or jugular veins had no significant effect. It was concluded that duodenal osmoconcentration to the degree that it exceeds body fluid tonicity contributes to the immediate satiety seen during a meal.

Animals↗
PubMed1978

Satiety effects of cholecystokinin and caerulein in rabbits.

Six adult rabbits were maintained on an 18 h fast, 6 h feeding schedule. At the end of the fast either 0.5-40 Ivy dog units (IDU)/kg cholecystokinin (CCK) or 0.9% NaCl were injected intravenously. Feed intake was then measured for 15 min. Significant depression of intake was found at 1 IDU/kg, a 50% depression of intake after 5.5 IDU/kg, and no intake after 40 IDU/kg. Caerulein in similar experiments gave significant depression of intake at 0.125 microgram/kg, a 50% depression after 0.28 microgram/kg, and no intake after 5.0 microgram/kg. In three of these rabbits subdiaphragmatic vagotomy did not abolish the satiety effects of CCK and caerulein. The synthetic octapeptide of CCK was less potent in causing satiety. After CCK or caerulein the rabbits showed typical postprandial behavior. Taste aversion tests failed to demonstrate a strong aversion to flavors associated with the compounds used. These results indicate that exogenous CCK can act as a satiety agent at levels of the same order as the physiological range.

Animals↗
PubMed1977

Food intake controls in the suckling pig: glucoprivation and gastrointestinal factors.

The energy balance of suckling Yorkshire pigs 1 day to 2 wk old was challenged by: food deprivation, glucoprivation, and caloric and noncaloric gastric loads delivered by intubation. tafter 2--4 h fasts, food intake greatly increased over nonfasted control intake during a 3-h refeeding period. This response occurred both when body weight gain was used as a measure of intake for pigs nursing on the sow and when intake was measured directly in bottle-fed pigs. Glucoprivation produced by 0.5--2 U/kg insulin did not stimulate food intake although plasma glucose fell to a mean of 49 mg/100 ml (43% of control) after 1 U/kg insulin. Gastric loads of water or 3% NACl depressed intake after 3-h fast, but 0.9% NaCl did not. All the caloric gastric loads depressed intake; in order of increasing effectiveness, they were: heavy cream, protein hydrolysate, corn oil, milk, 5% glucose, and 5% lactose. The carbohydrate loads were most effective, a result which indicates that the response was not to calories alone but to some specific nutrient, possibly glucose.

Animals↗
PubMed1975

Effects of gastric loads and food deprivation on subsequent food intake in suckling rats.

Suckling rats were subjected to deprivation periods of 6-8 hr. Intake following deprivation was greater in deprived than in nondeprived sucklings, but did not increase with increasing deprivation. Gastric loads of NaCl solutions depressed subsequent intake; 3% NaCl was more effective than .9% NaCl. Other gastric loads of varying osmotic and caloric value also depressed subsequent intake. In order of increasing effectiveness in depressing intake, the gastric loads were protein hydrolystate, heavy cream, water, milk, lactose, glucose, and corn oil. Effectiveness was unrelated to osmotic or caloric value of the load. Gastric fill and, possibly, some property of carbohydrate appear to be important determinants of satiety in the suckling rat.

Age Factors↗