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At least 73 records · Page 4Linked to original sources

PubMed2001

Second meal effect: modified sham feeding does not provoke the release of stored triacylglycerol from a previous high-fat meal.

The present study was carried out to determine whether cephalic stimulation, associated with eating a meal, was sufficient stimulus to provoke the release of stored triacylglycerol (TAG) from a previous high-fat meal. Ten subjects were studied on three separate occasions. Following a 12 h overnight fast, subjects were given a standard mixed test meal which contained 56 g fat. Blood samples were taken before the meal and for 5 h after the meal when the subjects were randomly allocated to receive either water (control) or were modified sham fed a low-fat (6 g fat) or moderate-fat (38 g fat) meal. Blood samples were collected for a further 3 h. Compared with the control, modified sham feeding a low- or moderate-fat meal did not provoke an early entry of TAG, analysed in either plasma or TAG-rich lipoprotein (TRL) fraction (density <1.006 kg/l). The TRL-retinyl ester data showed similar findings. A cephalic phase secretion of pancreatic polypeptide, without a significant increase in cholecystokinin levels, was observed on modified sham feeding. Although these data indicate that modified sham feeding was carried out successfully, analysis of the fat content of the expectorant showed that our subjects may have accidentally ingested a small amount of fat (0.7 g for the low-fat meal and 2.4 g for the moderate-fat meal). Nevertheless, an early TAG peak following modified sham feeding was not demonstrated in the present study, suggesting that significant ingestion of food, and not just oro-sensory stimulation, is necessary to provoke the release of any TAG stored from a previous meal.

Adult↗

PubMed2000

Short-term satiety in preschool children: a comparison between high protein meal and a high complex carbohydrate meal.

The aim of this study was to investigate whether a high protein meal has a different effect on short-term satiety in preschool children than a high carbohydrate meal by measuring their intake of a subsequent meal. Subjects were 35 normal preschool children of both genders aged 5 to 6 years. All children were healthy and randomly chosen from those who were attending to a day-care center where they received feeding at three meal times: breakfast, lunch and teatime. Children were weighed with light clothes following standard recommendations. They were normal according to the weight for height index, using the NCHS standards. Two meals with different levels of protein and carbohydrate and equal energy contents were assayed at lunch. The lunches were cooked dishes made from common ingredients. The high carbohydrate meal was consumed in greater amount than the high protein meal (P < 0.01) and a significantly greater energy intake was observed (P < 0.01). Food and energy intakes at teatime were greater with the high carbohydrate meal, but only the energy intake was significant (P < 0.05). When subjects consumed the high protein meal during lunch, they ate a significantly lower amount of protein in the subsequent meal, but the carbohydrate intake was similar. The long-term effects of a high protein diet remain to be investigated before recommending of a high protein for obese children.

Child↗

PubMed1979

[Food value of straw meal in the nutrition of pigs. 1. Digestibility of the nutrients and N-balance after feeding with partially hydrolized straw meal].

Straw Meal was mixed with concentrated HCl at a mass proportion of approximately 10 : 1. After a one-hour duration of action the mixture was diluted with water (in proporation to the added HCl volume the double amount of water) and steamed in an electric steaming caldron for one hour. The partially hydrolised final product was neutralised with calcium hydroxide (3,5 kg per 10 kg HCl). In a digestibility experiment 4 pigs were fed according to the differential method with barley (supplemented with lysine and methionine) without straw meal resp. with straw meal (717 g barley dry matter+386 g straw meal dry matter per animal and day for pigs with an average live weight of 64.3 kg). In this test 21.0% of the organic matter of partially hydrolised straw meal, 0.5% of the crude fibre and 42.3% of the N-free extractives were digestible. When the animals were fed with barley exclusively (1045 g dry matter per day and animal of an average body weight of 61,4 kg), 17,1% of the 26,0 t N per animal and day were excreted in feces. After the feeding with straw meal admixtures, 34,5% of the 20,9 g N per animal and day were excreted in feces. When the feed consisted of 1,99 kg barley, 220 g fish meal and 565 g straw meal (dry matter in each case) per animal and day for the same pigs with an average body weight of 97,1 kg a digestibility of the organic matter of the partially hydrolised straw meal of 24,6% was achieved. 24.3% of the nitrogen consumed (72.9 g) by each animal per day were excreted in feces. After slaughtering, the pH-value in the caecum sould be ascertained as 6.0 to 6.5. The conclusion of this is that partially hydrolised straw meal contains approximately 20% utilisable carbohydrates and has a positive dietic effect in the digestive tract.

Animal Feed↗

PubMed1997

Weight loss is greater with consumption of large morning meals and fat-free mass is preserved with large evening meals in women on a controlled weight reduction regimen.

The purpose of this study was to determine whether meal ingestion pattern [large morning meals (AM) vs. large evening meals (PM)] affects changes in body weight, body composition or energy utilization during weight loss. Ten women completed a metabolic ward study of 3-wk weight stabilization followed by 12 wk of weight loss with a moderately energy restricted diet [mean energy intake +/- SD = 107 +/- 6 kJ/(kg.d)] and regular exercise. The weight loss phase was divided into two 6-wk periods. During period 1, 70% of daily energy intake was taken as two meals in the AM (n = 4) or in the PM (n = 6). Subjects crossed over to the alternate meal time in period 2. Both weight loss and fat-free mass loss were greater with the AM than the PM meal pattern: 3.90 +/- 0.19 vs. 3.27 +/- 0.26 kg/6 wk, P < 0.05, and 1.28 +/- 0.14 vs. 0.25 +/- 0.16 kg/6 wk, P < 0.001, respectively. Change in fat mass and loss of body energy were affected by order of meal pattern ingestion. The PM pattern resulted in greater loss of fat mass in period 1 (P < 0.01) but not in period 2. Likewise, resting mid-afternoon fat oxidation rate was higher with the PM pattern in period 1 (P < 0.05) but not in period 2, corresponding with the fat mass changes. To conclude, ingestion of larger AM meals resulted in slightly greater weight loss, but ingestion of larger PM meals resulted in better maintenance of fat-free mass. Thus, incorporation of larger PM meals in a weight loss regimen may be important in minimizing the loss of fat-free mass.

Adipose Tissue↗

PubMed1999

Performance of beef cows receiving cull beans, sunflower meal, and canola meal as protein supplements while grazing native winter range in Eastern Colorado.

A 2-yr grazing performance study was conducted in Eastern Colorado to evaluate the effects of feeding raw cull beans (Phaseolus vulgaris) or canola meal, compared to sunflower meal, to beef cows grazing dormant, native winter range on body weight and body condition score (BCS) change, reproductive performance, and calf performance. Ninety-five pregnant, spring-calving crossbred cows (541 +/- 51 kg) in 1995 to 1996 and 65 cows (602 +/- 60 kg) in 1996 to 1997 were randomly assigned to one of five treatments (19 and 13 cows per treatment in 1995 to 1996 and 1996 to 1997, respectively): 1) unprocessed Great Northern beans to supply 182 g/d of CP (GNB); 2) canola meal to supply 182 g/d of CP (CM); 3) a mixture of Great Northern beans and sunflower meal, each to supply 91 g/d of CP, for a total of 182 g/d of CP (MIX); 4) sunflower meal to supply 182 g/d of CP (SFM+); and 5) sunflower meal to supply 91 g/d of CP (SFM-). Cow weight and body condition performance were broken into a gestation and a lactation phase in 1995 to 1996; calves were weighed at birth, at the end of the lactation phase in April, and at weaning the following September. Only gestation performance was monitored in 1996 to 1997, and subsequent calf birth and weaning weight were recorded. The SFM- group lost more weight during the gestation phase than other treatments (P < .05), yet no differences were detected for gestation phase daily BCS change, calf birth weight, lactation phase daily weight change, lactation phase daily BCS change, first-service conception rate to AI, or overall pregnancy rate. Off-test calf weight was higher in April for calves from dams of the SFM+ and CM treatments than for calves from dams on the GNB or SFM- treatments (P < .05), and calves from cows on the CM treatment were heavier in April than calves from cows on the MIX treatment (P < .05). No differences in calf weight were present at weaning. Consumption of beans by cows on the GNB treatment was low because of palatability problems. Mixing the beans with sunflower meal in the MIX treatment eliminated this problem. Canola meal, Great Northern beans, or a combination of sunflower meal and Great Northern beans were comparable to sunflower meal as protein supplements for beef cows grazing native winter range, despite obvious palatability problems with the beans.

Animal Feed↗

PubMed1988

Lactational response to soybean meal, heated soybean meal, and extruded soybeans with ruminally protected methionine.

Seventy-three high producing Holstein cows were arranged in a 3 X 2 factorial to evaluate three protein supplements (soybean meal, heat-treated soybean meal, and extruded blend of soybeans and soybean meal) without or with 15 g/head/d of ruminally protected DL-methionine during wk 4 through 16 postpartum. Total mixed diets contained (DM basis) 30% corn silage, 15% alfalfa hay, and 55% of the respective concentrate mix. Milk production was higher when cows were fed either heated soybean product instead of soybean meal. Methionine supplementation increased production when fed with soybean meal (32.2 and 33.8 kg/d) but not when fed with heat-treated soybean meal (34.5 and 33.0 kg/d) or extruded soybeans (36.2 and 34.4 kg/d). Milk fat percentages were lower with extruded soybeans (3.01, 2.93, and 2.66) and were similar without (2.83) or with (2.90) supplemental methionine. Milk protein percentages were highest when fed soybean meal, lowest with extruded soybeans (3.02, 2.92, and 2.87), and higher with supplemental methionine (2.91 and 2.96). Dry matter intake was higher when fed supplemental methionine (20.0 and 21.3 kg/d). Production of milk in early lactation high producing dairy cows was increased by supplementing a soybean meal diet with ruminally protected methionine or by replacing the soybean meal with heat-treated soybean meal, soybeans, or a mixture of the two.

Animal Feed↗

PubMed1994

Quality of patient meal service in hospitals: delivery of meals by dietary employees vs delivery by nursing employees.

OBJECTIVE: To compare patient assessment of meal-service quality and employee-service orientation in hospitals where dietary employees deliver meals trays and in hospitals where nursing employees deliver meal trays. DESIGN: Survey. SETTING: General, medical-surgical (not Veterans Administration) hospitals of 300 to 500 beds with a self-operated foodservice department and a centralized, conventional food production system. SUBJECTS: 552 patients and 192 employees in nine hospitals geographically dispersed in the midwestern and eastern United States. Dietary employees delivered meal trays in five of the hospitals and nursing employees delivered trays in four. MAIN OUTCOME MEASURES: On a five-point scale, patients indicated level of agreement with 16 statements about hospital meal service. Employees who delivered meal trays rated their agreement with 20 service orientation statements on a five-point scale. STATISTICAL ANALYSIS: Factor analysis with varimax rotation, chi 2 analysis, and analysis of variance. RESULTS: Patient assessment of the quality of meal service was multidimensional. Patients gave more positive ratings to characteristics of the personnel delivering the tray than to the quality of the food. Patients in hospitals were dietary employees delivered meal trays rated the quality of food significantly higher (P < .01) than did patients in hospitals where nursing employees delivered trays. Service orientation of the personnel delivering the trays was also multidimensional. Dietary and nursing employees did not differ in their personal motivation toward providing service; however, dietary employees rated the organizational support for providing service significantly higher (P < .001) than did nursing employees. Nursing employees were significantly more positive (P < .05) than dietary employees about their interactions with patients. CONCLUSIONS: Patient perceptions of service quality differed in hospitals where dietary employees delivered meal trays and in those where nursing personnel delivered trays. Dietary and nursing employees differed in some aspects of their service orientation.

Adult↗

PubMed1997

Mycotoxins in ingredients of animal feeding stuffs: I. Determination of Alternaria mycotoxins in oilseed rape meal and sunflower seed meal.

A multi-toxin method was developed for the detection of some of the known Alternaria mycotoxins, altenuene, iso-altenuene, alternariol, alternariol monomethyl ether, tenuazonic acid and altertoxin I in oilseed rape meal and sunflower seed meal. The method involves extraction of the toxins with an acidified mixture of acetonitrile: aqueous potassium chloride solution, followed by liquid-liquid extraction and further purification using gel permeation chromatography. The final extract is then examined on a reverse phase high performance liquid chromatographic gradient system with both fluorescence and UV detection. The average recoveries found were 94, 84, 109, 85, 66 and 93% for spiked oilseed rape meal samples and 91, 89, 96, 75, 61 and 102% for spiked sunflower meal samples with limits of determination of about 40, 50, 50, 40, 350 and 200 micrograms/kg for the above toxins, respectively. Detection limits were about 30% of these values. Thirty samples of oilseed rape meal and 22 samples of sunflower meal were examined using the methods developed. Twenty of the oilseed rape products which had been grown in the UK were free from contamination while 10 contained one or more of tenuazonic acid, alternariol and alternariol monomethyl ether. In contrast, all of the sunflower meal samples, of Argentinean, Indian or EC origin, were contaminated with one or more of alternariol, alternariol monomethyl ether and tenuazonic acid. Average levels of alternariol, alternariol monomethyl ether and tenuazonic acid were 68, 55 and 730 micrograms/kg, respectively for the contaminated samples of oilseed rape meal and 180, 100 and 1900 micrograms/kg, respectively for the contaminated samples of sunflower seed meal.

Alternaria↗

PubMed1987

[The effect of a straw meal on the crude protein and amino acid metabolism and digestibility of the crude nutrients in broiler hen breeds. 2. Digestibility of crude nutrients of rations and 15N from a straw meal and wheat].

In experiments with colostomized broiler hens apparent digestibility of the crude nutrients of the ration after straw meal supplements of 20, 30 and 40 g per animal was determined. In addition, the 15N digestibility of straw meal and wheat was ascertained on the basis of straw meal supplements. The digestibility of the crude nutrients of the rations decreased significantly (P less than 0.05) after the straw meal supplement. The adaptation of the test animals to the straw meal intake resulted, at a daily consumption of 20 g straw meal, in an increase of the apparent crude fat digestibility (P less than 0.05) in dependence on the time of straw meal feeding, in which the original values without straw meal supplement were not reached. The digestibility of the 15N excess (15N') of the wheat was, at 86 +/- 1%, largely independent of the straw meal intake. The apparent digestibility of the straw-15N excess in broiler hens of 42 +/- 8 to 55 +/- 2% is surprisingly high.

Amino Acids↗

PubMedDate not supplied

Effects of meal size, meal type, body temperature, and body size on the specific dynamic action of the marine toad, Bufo marinus.

Specific dynamic action (SDA), the accumulated energy expended on all physiological processes associated with meal digestion, is strongly influenced by features of both the meal and the organism. We assessed the effects of meal size, meal type, body temperature, and body size on the postprandial metabolic response and calculated SDA of the marine toad, Bufo marinus. Peak postprandial rates of O(2) consumption (.V(O2)) and CO(2) production (.V(CO2)) and SDA increased with meal size (5%-20% of body mass). Postprandial metabolism was impacted by meal type; the digestion of hard-bodied superworms (Zophobas larva) and crickets was more costly than the digestion of soft-bodied earthworms and juvenile rats. An increase in body temperature (from 20 degrees to 35 degrees C) altered the postprandial metabolic profile, decreasing its duration and increasing its magnitude, but did not effect SDA, with the cost of meal digestion remaining constant across body temperatures. Allometric mass exponents were 0.69 for standard metabolic rate, 0.85 for peak postprandial .V(O2), and 1.02 for SDA; therefore, the factorial scope of peak postprandial .V(O2) increased with body mass. The mass of nutritive organs (stomach, liver, intestines, and kidneys) accounted for 38% and 20% of the variation in peak postprandial .V(O2) and SDA, respectively. Toads forced to exercise experienced 25-fold increases in .V(O2) much greater than the 5.5-fold increase experience during digestion. Controlling for meal size, meal type, and body temperature, the specific dynamic responses of B. marinus are similar to those of the congeneric Bufo alvarius, Bufo boreas, Bufo terrestris, and Bufo woodhouseii.

Animals↗

PubMed2006

Specific dynamic action of ambystomatid salamanders and the effects of meal size, meal type, and body temperature.

The past decade has witnessed a dramatic increase in studies of amphibian and reptile specific dynamic action (SDA). These studies have demonstrated that SDA, the summed energy expended on meal digestion and assimilation, is affected significantly by meal size, meal type, and body size and to some extent by body temperature. While much of this attention has been directed at anuran and reptile SDA, we investigated the effects of meal size, meal type, and body temperature on the postprandial metabolic responses and the SDA of the tiger salamander (Ambystoma tigrinum tigrinum). We also compared the SDA responses among six species of Ambystoma salamanders representing the breadth of Ambystoma phylogeny. Postprandial peaks in VO(2) and VO(2), duration of elevated metabolism, and SDA of tiger salamanders increased with the size of cricket meals (2.5%-12.5% of body mass). For A. tigrinum, as for other ectotherms, a doubling of meal size results in an approximate doubling of SDA, a function of equal increases in peak VO(2) and duration. For nine meal types of equivalent size (5% of body mass), the digestion of hard-bodied prey (crickets, superworms, mealworms, beetles) generated larger SDA responses than the digestion of soft-bodied prey (redworms, beetle larvae). Body temperature affected the profile of postprandial metabolism, increasing the peak and shortening the duration of the profile as body temperature increased. SDA was equivalent among three body temperatures (20 degrees, 25 degrees, and 30 degrees C) but decreased significantly at 15 degrees C. Comparatively, the postprandial metabolic responses and SDA of Ambystoma jeffersonianum, Ambystoma maculatum, Ambystoma opacum, Ambystoma talpoideum, Ambystoma texanum, and the conspecific Ambystoma tigrinum mavortium digesting cricket meals that were 5% of their body mass were similar (independent of body mass) to those of A. t. tigrinum. Among the six species, standard metabolic rate, peak postprandial VO(2), and SDA scaled with body mass with mass exponents of 0.72, 0.78, and 1.05, respectively.

Animals↗

PubMed1995

Procurement time as a determinant of meal frequency and meal duration.

Foraging involves the expenditure of both time and effort in the acquisition of food; animals typically modify their meal patterns so as to reduce these expenditures or costs. The contribution of time, as compared with effort, to the overall cost perceived by an animal is not known. We investigated the effect of foraging time as a cost independent of effort by measuring the meal patterns of rats living in a laboratory foraging simulation in which they earned all their daily intake. They pressed a bar once to initiate an interval (procurement interval) leading to the presentation of a large cup of food from which they could eat a meal of any size. As the length of the interval increased from 1 s to 46 hr, meal frequency decreased regularly. Meal size increased in a compensatory fashion, and total daily intake was conserved through an interval of 23 hr. The changes in meal frequency occurred because of changes in the rat's latency to bar press after each meal. The functions relating meal frequency and size to the procurement interval were of the same shape as those seen when cost is the completion of a bar-press requirement, which entails the expenditure of both effort and time. When the bar-press requirement was increased to 10, meal frequency was reduced, but time and effort did not appear to simply add together in the rat's perception of cost. These data reveal that time is preceived to be a cost by rats foraging in this laboratory environment. These results suggest that the time parameters of foraging are different from those of consumption.

Animals↗

PubMed1989

Corn gluten meal and blood meal mixture for dairy cows in midlactation.

Twelve midlactation Holstein cows were assigned to a switchback design with 4-wk periods to compare a corn gluten meal and blood meal mixture with soybean meal as supplemental protein sources. All experimental diets contained 60% ammoniated corn silage, on a dry basis, and a corn and oats (2:1) basal concentrate mixture. Diets were: urea control (12.5% CP); soybean meal (16.1% CP); low protein (14.3% CP) corn gluten and blood meal mixture; and high protein (16.8% CP) corn gluten and blood meal mixture. Cows fed the control diet consumed less DM, and produced less milk containing a lower percentage of protein than cows fed other diets. Protein efficiency and milk fat percentage were higher for cows fed the control diet than for cows fed the natural protein diets. Fat-corrected milk and fat yields did not differ among diets. The high protein diets (16.1 and 16.8% CP) decreased protein efficiency and increased SNF percentage. Milk yield per unit of DM intake was higher when cows fed the lower degradable protein source (corn gluten-blood meal) than when they were fed soybean meal. The low degradable protein mixture produced a similar lactation response to soybean meal at both the high and low concentrations of total dietary protein. This study indicates that the dietary protein and undegradable protein concentration needed by midlactation Holstein fed complete mixed diets may be lower than generally recommended.

Amino Acids↗

PubMed1992

Effect of fish meal and expeller-processed soybean meal fed to dairy cows receiving bovine somatotropin (sometribove).

Forty-eight multiparous cows were blocked by calving date and milk production and assigned randomly to a TMR formulated to contain 68 or 55% of dietary CP as ruminally degradable CP. Diets contained corn silage, alfalfa haylage, and ground corn. Supplemental CP was soybean meal for the control diet or a combination of soybean meal, expeller-processed soybean meal, and fish meal for the low degradable protein diet. Two 10-wk phases began on d 31 +/- 3 (phase 1) and 110 +/- 7 postpartum [phase 2, all cows received subcutaneous implantations of pelleted (400 mg) bST (sometribove) every 14 d]. Dietary energy, CP, ruminally degradable CP, NDF, and ADF were similar between dietary treatments. Production of FCM increased in response to bST but was not affected by dietary treatment. Cows fed the expeller-processed soybean meal and fish meal TMR produced milk that contained less milk fat in phase 1 and less milk protein content in both phases. The DMI, BW, and body condition scores were not affected by diet. Hematocrit, plasma urea N, albumin, total protein, creatinine, glucose, and serum insulin were similar between dietary treatments. Replacing soybean meal with expeller processed soybean meal and fish meal did not affect ruminal degradation of protein or milk production but decreased milk fat and protein contents.

Animal Feed↗

PubMed1999

Postprandial lipoprotein, glucose and insulin responses after two consecutive meals containing rapeseed oil, sunflower oil or palm oil with or without glucose at the first meal.

There is increasing evidence that the degree of postprandial lipaemia may be of importance in the development of atherosclerosis and IHD. Postprandial lipid, lipoprotein, glucose, insulin and non-esterified fatty acid (NEFA) concentrations were investigated in eleven healthy young males after randomized ingestion of meals containing rapeseed oil, sunflower oil or palm oil with or without a glucose drink. On six occasions each subject consumed consecutive meals (separated by 1.75 h) containing 70 g (15 g and 55 g respectively) of each oil. On one occasion with each oil 50 g glucose was taken with the first meal. One fasting and fifteen postprandial blood samples were taken over 9 h. There were no statistically significant differences in lipoprotein and apolipoprotein responses after rapeseed, sunflower and palm oils, whereas insulin responses were lower after sunflower oil than after rapeseed oil (ANOVA, P = 0.04). The NEFA and triacylglycerol concentrations at 1.5 h were reduced when 50 g glucose was taken with the first meal (ANOVA, P < 0.0001 and P < 0.05 respectively), regardless of meal fatty acid composition. In conclusion, the consumption of glucose with a mixed meal containing either rapeseed, sunflower or palm oil influenced the immediate triacylglycerol and NEFA responses compared with the same meal without glucose, whereas no significant effect on postprandial lipaemia after a subsequent meal was observed. The fatty acid composition of the meal did not significantly affect the lipid and lipoprotein responses, whereas an effect on insulin responses was observed.

Adult↗

PubMed1983

Accentuated response to raw soya-bean meal by meal feeding.

Diets containing raw soya-beans (RSD) when fed ad libitum cause reduction in growth rate and food utilization, enlargement of the pancreas and increase of its enzyme synthesis. A single meal of raw soya-beans with corn (1:9), tube-fed to geese, caused about 90% mortality, while geese, tube-fed with corn alone, did not show any negative response. No mortality occurred when geese were fed a similar diet ad libitum. Two-week old chicks were fed ad libitum or by tube, twice a day, similar amounts of RSD or heated soya-bean diet (HSD). While the chicks tube-fed HSD behaved similarly to those feeding freely, the chicks tube-fed RSD collapsed after one week. The thymus and bursa of fabricii were atrophied in the RSD tube-fed chicks. Diets containing increasing amounts of raw soya-bean meal (0,20%, 42%, and 80%) were fed freely to weanling rats or as one 4 h meal per day. All the rats fed the 4 h meal containing either 42% or 80% raw soya-bean meal died within 3 days; all the others survived. The rats were trained to meal-feeding by gradual reduction of their access to food. The negative effects of the RSD, i.e. reduced food intake and body weight gain, pancreas enlargement, were much more pronounced in the meal-fed rats than in those fed ad libitum. The differences increased by increasing dietary trypsin inhibitor (TI) (raw soya-bean meal).

Animal Feed↗

PubMed1992

Meal-stimulated canine jejunal ionic absorption. Effect of direct jejunal meal delivery and premeal intravenous hydration.

The ingestion of a meal stimulates water and ion absorption from the small intestine. The administration of nutrient substances directly to the small bowel can cause dumping symptoms, with intraluminal fluid accumulation and relative systemic hypovolemia. This study compared the effect of oral versus direct jejunal meal delivery on jejunal water and ion absorption, with and without premeal intravenous saline infusion. Jejunal absorption studies (N = 40) were performed on dogs with 25 cm proximal jejunal Thiry-Vella fistulas and feeding jejunostomies. Luminal perfusion with [14C]PEG was used to calculate fluxes of water and electrolytes. Five groups were randomly studied: (1) intravenous 0.9% saline alone, (2) oral meal alone, (3) intravenous 0.9% saline plus oral meal, (4) jejunal meal alone, and (5) intravenous 0.9% saline plus jejunal meal. Hydration status was assessed hourly by measurement of hematocrit. Water and electrolyte absorption was significantly stimulated by both oral and jejunal meal delivery (P less than 0.01). Intravenous saline hydration significantly reduced the hematocrit (P less than 0.05) but did not alter the proabsorptive response to an oral or jejunal meal. In conclusion, a postprandial signal for proximal jejunal water and electrolyte absorption was stimulated equally by orally or jejunally administered nutrients and was not affected by premeal hydration. These data support the hypothesis that the proabsorptive signal that stimulates water and ion absorption is an enteroenteric phenomenon originating from the small intestine, without implicating pathophysiologic events such as hypovolemia or dumping.

Animals↗

PubMed1987

Lithium chloride, cholecystokinin and meal patterns: evidence that cholecystokinin suppresses meal size in rats without causing malaise.

Gut hormones which are proposed as natural satiety factors may act through malaise to suppress short-term feeding instead of through a normal physiological process. Evaluation of the ability of candidate satiety hormones to serve as the unconditioned stimulus in the development of a conditioned taste aversion is not adequate evidence of malaise since agents which do not produce malaise in humans are also capable of conditioning aversions. Examination of the patterns of eating behavior when drugs are given during a meal in rats may serve as a better test of the potential of an agent to produce illness. To evaluate this approach, LiCl (a known aversive agent) was infused into five rats at the start of each free-feeding meal at a dose of 1.9 mg/meal/rat for four days and at 3.8 mg/meal/rat for an additional four days. Feeding patterns during drug infusion were compared with patterns for six days when no drugs were infused. LiCl infusion produced a significant dose-dependent reduction in feeding frequency while the size and duration of meals were not changed. At the higher dose of lithium, daily meal number was reduced from a normal 13.2 +/- 1.4 to 9.9 +/- 0.5 meals/day. This pattern of behavior is significantly different from the behavior exhibited when cholecystokinin octapeptide (CCK-8) was infused using the same paradigm. CCK-8 significantly reduced meal size while meal frequency increased to compensate for the smaller meals. These findings suggest that LiCl infusion during a meal will lead to an aversion to feeding while CCK-8 is not effective at producing an aversion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗