Intragastric glucose but not fructose conditions robust flavor preferences in rats

1993 ◽  
Vol 265 (2) ◽  
pp. R320-R325 ◽  
Author(s):  
A. Sclafani ◽  
C. Cardieri ◽  
K. Tucker ◽  
D. Blusk ◽  
K. Ackroff
Keyword(s):  
Conditional Stimulus ◽  
Flavor Preference ◽  
Prior Work ◽  
Significant Preference ◽  
Choice Tests ◽  
Flavored Water ◽  
Subsequent Choice ◽  
Food Conditioning ◽  
Ad Libitum ◽  
Reinforcing Effects

Prior work indicates that glucose and fructose differ in their postingestive reinforcing effects. The present study investigated this phenomenon by training rats to associate the intake of flavored water with intragastric (IG) infusions of 16% sugar solutions. In experiment 1, rats had one flavor [conditional stimulus (CS)] paired with IG sugar infusions (CS+; e.g., cherry) and another flavor paired with IG water (CS-; e.g., grape) 23 h/day; Chow was available ad libitum. In subsequent choice tests, rats infused with glucose displayed a strong preference (89%) for the CS+ flavor, whereas rats infused with fructose showed only a small and nonreliable CS+ flavor preference (62%). When next trained to associate one flavor (e.g., orange) with IG glucose and another flavor (e.g., strawberry) with IG fructose, rats in both groups developed a significant preference (81%) for the glucose-paired flavor. In experiment 2, food-deprived rats were trained 2 h/day to associate a CS+ flavor with IG sugar and a CS- flavor with IG water infusions. The glucose-reinforced rats displayed a near-total preference (95%) for the CS+ flavor, whereas fructose-reinforced rats showed a much smaller CS+ preference (67%). The preference findings indicate that the postingestive consequences of glucose are much more reinforcing than those of fructose. It appears that food conditioning is mediated by chemospecific actions of nutrients rather than their general satiating or energy repleting effects.

Robust conditioned flavor preference produced by intragastric starch infusions in rats

1988 ◽  
Vol 255 (4) ◽  
pp. R672-R675 ◽  
Author(s):  
A. Sclafani ◽  
J. W. Nissenbaum
Keyword(s):  
Extinction Test ◽  
Flavor Preference ◽  
Choice Tests ◽  
Flavored Water ◽  
Ad Libitum ◽  
Conditioned Flavor

Rats were intragastrically infused with hydrolyzed starch (16% Polycose) or water as they drank cherry- or grape-flavored water during 23-h/day tests; chow was available ad libitum. After 4 conditioning days the rats displayed a near-total preference (96%) for the starch-paired flavor over the water-paired flavor in two-choice tests. This conditioned flavor preference persisted during a 4-day extinction test when both flavors were paired with water infusions. The results demonstrate that the postingestive actions of starch are rewarding to nondeprived rats and can condition strong and long-lasting flavor preferences.

scholarly journals Fructose- and glucose-conditioned preferences in FVB mice: strain differences in post-oral sugar appetition

2014 ◽  
Vol 307 (12) ◽  
pp. R1448-R1457 ◽  
Author(s):  
Anthony Sclafani ◽  
Steven Zukerman ◽  
Karen Ackroff
Keyword(s):  
Strain Differences ◽  
Choice Test ◽  
Significant Preference ◽  
Physiological Processes ◽  
Ad Libitum ◽  
Preference Conditioning ◽  
Conditioned Flavor

Recent studies indicate that, unlike glucose, fructose has little or no post-oral preference conditioning actions in C57BL/6J (B6) mice. The present study determined whether this is also the case for FVB mice, which overconsume fructose relative to B6 mice. In experiment 1, FVB mice strongly preferred a noncaloric 0.1% sucralose + 0.1% saccharin (S+S) solution to 8% fructose in a 2-day choice test but switched their preference to fructose after separate experience with the two sweeteners. Other FVB mice displayed a stronger preference for 8% glucose over S+S. In a second experiment, ad libitum-fed FVB mice trained 24 h/day acquired a significant preference for a flavor (CS+) paired with intragastric (IG) self-infusions of 16% fructose over a different flavor (CS−) paired with IG water infusions. IG fructose infusions also conditioned flavor preferences in food-restricted FVB mice trained 1 h/day. IG infusions of 16% glucose conditioned stronger preferences in FVB mice trained 24- or 1 h/day. Thus, fructose has post-oral flavor conditioning effects in FVB mice, but these effects are less pronounced than those produced by glucose. Further studies of the differential post-oral conditioning effects of fructose and glucose in B6 and FVB mice should enhance our understanding of the physiological processes involved in sugar reward.

Effect of Beverage Flavor on Body Hydration in Hong Kong Chinese Children Exercising in a Hot Environment

2014 ◽  
Vol 26 (2) ◽  
pp. 177-186 ◽  
Author(s):  
Stephen Heung-Sang Wong ◽  
Feng-Hua Sun
Keyword(s):  
Intermittent Exercise ◽  
Latin Square ◽  
Rest Period ◽  
Chinese Children ◽  
Total Fluid Intake ◽  
Hot Environment ◽  
Humid Environment ◽  
Flavored Water ◽  
Ad Libitum ◽  
Body Fluid Balance

The purpose of the current study was to examine the effect of flavor on voluntary drinking and thermoregulatory responses in Chinese boys and girls exercising intermittently in a hot environment. Fourteen boys and girls (9 to 11 years old) performed four 3-hour intermittent exercise sessions (20-min walking sessions at 50% VO2peak followed by a 25-minute rest period) in a hot and humid environment (~30 °C ambient temperature and ~70% relative humidity). The participants consumed 1 of 4 beverages ad libitum in a randomized sequence by using a Latin-square principle: unflavored water (W), orange-flavored water (OF), lemon-flavored water (LF), and grape-flavored water (GF). No differences were observed in the total fluid intake (W vs. OF vs. LF vs. GF: Boys, 441 ± 114 vs. 493 ± 106 vs. 387 ± 83 vs. 568 ± 146 ml; Girls, 613 ± 131 vs. 923 ± 204 vs. 825 ± 157 vs. 790 ± 166 ml), urine and sweat output, and physiological perceptual variables among trials and between sexes. The results suggested that Chinese children can maintain body fluid balance while exercising moderately in a hot and humid environment by ad libitum drinking. The flavor of the beverages had no impact on the voluntary drinking and the state of hydration in the current study.

Effect of drink flavor and NaCL on voluntary drinking and hydration in boys exercising in the heat

1996 ◽  
Vol 80 (4) ◽  
pp. 1112-1117 ◽  
Author(s):  
B. Wilk ◽  
O. Bar-Or
Keyword(s):  
Heart Rate ◽  
Body Weight ◽  
Latin Square ◽  
Hydration Status ◽  
Stomach Fullness ◽  
O2 Uptake ◽  
Flavored Water ◽  
Voluntary Dehydration ◽  
Ad Libitum ◽  
Skin Temperatures

This study was intended to assess the influence of drink flavor and composition on voluntary drinking and hydration status in children exercising intermittently at 35 +/- 1 degrees C and 45-50% relative humidity. Twelve boys (9-12 yr) performed three 3-h identical sessions (four 20-min cycling bouts at 50% maximal O2 uptake followed by 25-min rest). One of three beverages (chilled to 8-10 degrees C) was assigned to each session in a Latin-square sequence: unflavored water (W), grape-flavored water (FW), and grape-flavored water plus 6% carbohydrate and 18 mmol/l NaCl (CNa). Drinking was ad libitum. Body weight, heart rate, rectal and skin temperatures, and thirst and stomach fullness perceptions were monitored periodically. Total intake was 610, 882, and 1,157 g in W, FW, and CNa, respectively (CNa-W and CNa-FW; P < 0.05). Hypohydration was observed with W (-0.65% body wt) and FW (-0.32% body wt), but drinking CNa resulted in slight overhydration (+0.47% body wt, CNa-W, CNa-FW; P < 0.05). Other physiological and all perceptual variables were insignificantly different among trails. In conclusion, while flavoring of water reduces children's voluntary dehydration, further addition of 6% carbohydrates and 18 mmol/l NaCl prevents it altogether.

Some physical, metabolic, and sensory components in the appetite for glucose

1962 ◽  
Vol 203 (6) ◽  
pp. 1043-1054 ◽  
Author(s):  
Harry L. Jacobs
Keyword(s):  
Free Choice ◽  
General State ◽  
Gastric Distention ◽  
Caloric Density ◽  
Glucose Intake ◽  
Choice Tests ◽  
Ad Libitum ◽  
Osmotic Effects ◽  
Ad Libitum Feeding ◽  
Osmotic Properties

Glucose appetite in satiated, hungry, or thirsty rats was measured by ingestion of glucose and of saccharin solutions in free-choice tests. Type, concentration, and number of choices were determined with and without intragastric or intraperitoneal loads of metabolizable and nonmetabolizable sugars, urea, or NaCL. Taste and calories were evaluated as rate modulators in ad libitum feeding. Gastric distention, sweetness, and the chemical and osmotic properties of ingested glucose were evaluated as sources of satiety signals. The results indicate that: a) Taste is not a factor in ad libitum glucose intake; the caloric density of the solution is implicated. b) The satiety effect of intragastric glucose loads in independent of gastric distention or its potential osmotic effects. However, glucose intake may be related to the general state of hydration. c) The response to glucose and sucrose loads suggests the operation of a preabsorptive chemoreceptor system. The use of glucose appetite as a tool in the concomitant investigation of hunger and thirst is discussed.

High-fat diet preference and overeating mediated by postingestive factors in rats

1998 ◽  
Vol 275 (5) ◽  
pp. R1511-R1522 ◽  
Author(s):  
François Lucas ◽  
Karen Ackroff ◽  
Anthony Sclafani
Keyword(s):  
High Fat Diet ◽  
Liquid Diet ◽  
Flavor Preference ◽  
High Fat ◽  
High Carbohydrate ◽  
Flavored Solution ◽  
Diet Preference ◽  
Choice Tests ◽  
Selection Of

The role of postingestive factors in the preference for and overconsumption of high-fat (HF) foods, relative to high-carbohydrate (HC) foods, was investigated using a self-regulated intragastric feeding procedure. On one-bottle training days, rats drank one flavored saccharin solution [conditioned stimulus (CS) + HF] paired with intragastric infusions of an HF liquid diet, a second flavored solution (CS+HC) paired with an HC liquid diet, and a third flavored solution (CS−) paired with intragastric water. The diets had the same energy and protein content; the CS solutions and infusions along with chow were available ad libitum. The rats drank more CS and self-infused more diet on HF than HC training days. In two-bottle choice tests, the rats preferred the CS+HF to the CS+HC and both CS+HF and CS+HC to the CS−. The rats consumed more CS+HF than CS+HC by taking more bouts per day; bout sizes did not reliably differ. In a subsequent experiment, rats preferred the CS+HF even though diet intakes in training were matched. In a final experiment, the CS+HC and CS+HF intakes were equated in training by diluting the HC diet. Now the rats did not reliably prefer the CS+HF to the CS+HC, yet caloric intakes were much higher on CS+HF than CS+HC training days. Thus, relative to an isocaloric HC diet, the postingestive effects of HF diets stimulate overeating and condition a stronger flavor preference. Reduced satiety rather than increased reinforcement may be the direct promoter of overeating. However, postingestive reinforcement may enhance the selection of HF foods when a choice of HF and HC foods is available.

Drink composition, voluntary drinking, and fluid balance in exercising, trained, heat-acclimatized boys

1999 ◽  
Vol 86 (1) ◽  
pp. 78-84 ◽  
Author(s):  
Anita M. Rivera-Brown ◽  
Randall Gutiérrez ◽  
Juan Carlos Gutiérrez ◽  
Walter R. Frontera ◽  
Oded Bar-Or
Keyword(s):  
Fluid Balance ◽  
Aerobic Power ◽  
Maximal Aerobic Power ◽  
Sweat Loss ◽  
Wet Bulb Globe Temperature ◽  
Flavored Water ◽  
Voluntary Dehydration ◽  
Ad Libitum ◽  
Globe Temperature ◽  
Body Fluid Balance

This study examined the effects of beverage composition on the voluntary drinking pattern, body fluid balance, and thermoregulation of heat-acclimatized trained boys exercising intermittently in outdoor conditions (wet bulb globe temperature 30.4 ± 1.0°C). Twelve boys (age 13.4 ± 0.4 yr) performed two 3-h sessions, each consisting of four 20-min cycling bouts at 60% maximal aerobic power alternating with 25-min rest. One of two beverages was assigned: unflavored water (W) or flavored water plus 6% carbohydrate and 18 mmol/l Na (CNa). Drinking was ad libitum. Total intake was higher ( P < 0.05) during CNa (1,943 ± 190 g) compared with W (1,470 ± 143 g). Euhydration was maintained with CNa (+0.18% body wt), but a mild dehydration resulted with W (−0.94% body wt; P < 0.05). Sweat loss, much higher than previously published for children of similar age, was similar between conditions (CNa = 1,644.7 ± 117.5; W = 1,750.2 ± 152.7 g). The increase in rectal temperature (CNa = 0.86 ± 0.3; W = 0.76 ± 0.1°C), heart rate, and all perceptual variables did not differ between conditions. In conclusion, a flavored carbohydrate-electrolyte drink prevents voluntary dehydration in trained heat-acclimatized boys exercising in a tropical climate despite their large sweat losses. Because hydration changes were minor, the thermoregulatory strain observed was similar between conditions.

Cholecystokinin conditions flavor preferences in rats

1991 ◽  
Vol 260 (1) ◽  
pp. R179-R185 ◽  
Author(s):  
C. Perez ◽  
A. Sclafani
Keyword(s):  
Food Preferences ◽  
The Other ◽  
Low Doses ◽  
Flavor Preference ◽  
Choice Tests ◽  
Conditioning Effect ◽  
The One ◽  
Preference Conditioning ◽  
Preference Tests ◽  
Reliable Preference

The present study investigated whether cholecystokinin (CCK), an intestinal hormone that is a putative satiety agent, can condition flavor preference in rats. In experiment 1 food-deprived rats were trained to consume two different-flavored saccharin solutions in separate one-bottle tests. One flavor (the CS+) was paired with intraperitoneal injections of CCK octapeptide (0.125-4 micrograms/kg); the other flavor was paired with intraperitoneal injections of saline. Flavor preferences were then assessed in subsequent two-bottle choice tests. The 0.125 and 0.25 micrograms/kg doses failed to suppress CS+ intake or produce flavor preferences. CCK at 0.5 micrograms/kg did not reliably suppress CS+ intake in the one-bottle tests but produced a reliable preference for the CS+ in the two-bottle tests; percent CS+ intakes ranged from 50 to 62% in the four preference tests. At 1 microgram/kg, CCK suppressed CS+ intake and produced a marginal preference for the CS+. The 2 micrograms/kg dose suppressed CS+ intake but failed to condition a CS+ preference. The 4 micrograms/kg dose of CCK produced a potent suppression of CS+ intake and a strong aversion to that flavor. The preference conditioning effect of CCK at 0.5 microgram/kg was replicated in a second experiment using flavored Polycose solutions. The finding that low doses of CCK condition flavor preferences in rats is compatible with the hypothesis that endogenous CCK can mediate satiety and further suggests a role for CCK in learned food preferences. The aversion conditioned by the highest dose of CCK does not detract from this interpretation, since food, if consumed in excess, can also have aversive consequences.

Light and electron microscopic investigation of adenohypophyses of germfree, food-restricted, and germfree-food restricted aging, male lobund-wistar rats

1988 ◽  
Vol 46 ◽  
pp. 352-353
Author(s):  
G. Ilse ◽  
K. Kovacs ◽  
N. Ryan ◽  
T. Sano ◽  
L. Stefaneanu ◽  
...  
Keyword(s):  
Wistar Rats ◽  
Microscopic Investigation ◽  
Electron Microscopic Investigation ◽  
Aging Male ◽  
Sprague Dawley ◽  
Electron Microscopic ◽  
Sprague Dawley Rats ◽  
Old Rats ◽  
Ad Libitum ◽  
Microscopic Findings

Germfree state and food restriction have been shown to increase life span and delay tumor occurrence in rats. We report here the histologic, immunocytochemical and electron microscopic findings of adenohypophyses of aging, male Lobund-Wistar rats raised at Lobund Laboratories. In our previous study, the morphologic changes in the adenohypophyses of old rats have been extensively investigated by histology, immunocytochemistry and electron microscopy. Lactotroph adenomas were frequent in Long-Evans and Sprague-Dawley rats, whereas gonadotroph adenomas were frequent in Sprague-Dawley and Wistar rats.Male Lobund-Wistar rats were divided into four groups: 1) conventional, which were raised under normal non-germfree environment and received food ad libitum; 2) germfree-food ad libitum; 3) conventional environment-food restricted and 4) germfree-food restricted. The adenohypophyses were removed from 6-month-, 18-month- and 30-month-old rats. For light microscopy, adenohypophyses were fixed in formalin and embedded in paraffin.

Alteration of Mitochondria in Oxythiamine-Induced, Acute Thiamine Deficiency in the Mouse

1976 ◽  
Vol 34 ◽  
pp. 284-285
Author(s):  
Itaru Watanabe ◽  
Dante G. Scarpelli
Keyword(s):  
Electron Microscopy ◽  
Adult Male ◽  
Thiamine Deficiency ◽  
Light And Electron Microscopy ◽  
Fatty Change ◽  
Deficient Diet ◽  
Subcutaneous Injections ◽  
Swiss Mice ◽  
Time Period ◽  
Ad Libitum

Acute thiamine deficiency was produced in mice by the administration of oxythiamine, a thiamine analogue, superimposed upon a thiamine deficient diet. Adult male Swiss mice (30 gm. B.W.) were fed with a thiamine deficient diet ad libitumand were injected with oxythiamine (170 mg/Kg B.W.) subcutaneously on days 4 and 10. On day 11, severe lassitude and anorexia developed, followed by death within 48 hours. The animals treated daily with subcutaneous injections of thiamine (300 μg/Kg B.W.) from day 11 through 15 were kept alive. Similarly, feeding with a diet containing thiamine (600 μg/Kg B.W./day) from day 9 through 17 reversed the condition. During this time period, no fatal illness occurred in the controls which were pair-fed with a thiamine deficient diet.The oxythiamine-treated mice showed a significant enlargement of the liver, which weighed approximately 1.5 times as much as that of the pair-fed controls. By light and electron microscopy, the hepatocytes were markedly swollen due to severe fatty change and swelling of the mitochondria.

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