Biomedical subjects

A Sclafani

Publications and source records attributed to A Sclafani.

At least 91 records · Page 5Linked to original sources

PubMed1988

Taste preferences of squirrel monkeys and bonnet macaques for Polycose, maltose and sucrose.

The taste preferences of adult male squirrel monkeys and bonnet macaques for Polycose, maltose, and sucrose solutions were compared in 24 hr/day solution vs. water tests. Solution concentrations of 0.01 M, 0.05 M, 0.10 M, and 0.20 (Polycose) or 0.50 M (maltose and sucrose) were tested. The squirrel monkeys displayed a stronger preference for sucrose than for maltose or Polycose. In fact, at most concentrations tested, the squirrel monkeys did not consume more maltose or Polycose than water. The bonnet macaque monkeys, on the other hand, displayed preferences for maltose and Polycose that were as strong as their sucrose preference. Also, the bonnet macaques' maltose and Polycose preferences exceeded those of the squirrel monkeys. The two species did not reliably differ in their sucrose preferences. The results suggest that bonnet macaques, like rats, have taste receptors for starch-derived polysaccharides, whereas the squirrel monkeys, like humans, may lack such receptors. The taste preference profiles are consistent with the natural food preferences of the two monkey species.

Animals↗

PubMed1988

A comparison of the effects of atropine on real-feeding and sham-feeding of sucrose in rats.

In Experiment 1 the influence of atropine methyl nitrate on the sham-feeding response of adult female rats to a sucrose solution was determined. Atropine (1 or 5 mg/kg) reliably suppressed the sham-intake of sucrose when the drug was administered 30 or 0 min prior to, or 17 min after the start of the feeding session. The suppressive effect was less, however, when the drug was administered 30 min before testing compared to the other two injection-test conditions. In Experiment 2 atropine failed to reliably decrease the real-feeding of a sucrose solution whether it was injected 30, 15, or 0 min prior to testing. These results were replicated in Experiment 3; atropine (0 min injection-test interval) reduced the sham-intake but not the real-intake of a sucrose solution. However, atropine decreased the rate of feeding under both real- and sham-feeding conditions. The fact that atropine reduced feeding rate but not meal size in the real-feeding condition was attributed to the drug's lack of effect on postingestive satiety. The present findings along with other recent results indicate that (1) the injection-test interval is a potentially important variable in studies involving atropine; (2) results obtained with sham-feeding animals do not always generalize to real-feeding animals; and (3) cholinergically-mediated cephalic responses are of questionable importance in the control of meal size.

Animals↗

PubMed1988

Starch-based conditioned flavor preferences in rats: influence of taste, calories and CS-US delay.

Six experiments examined the rat's preference for flavors associated with hydrolysed starch (Polycose) solutions. Hungry rats developed a preference for a flavor (CS+) mixed into a saccharin-sweetened 16% Polycose solution over a flavor (CS-) mixed in saccharin-water. The addition of acarbose, a drug which inhibits starch digestion, to the Polycose solution blocked the flavor preference. This finding indicates that it is the postingestive rather than the taste properties of Polycose that condition flavor preferences. Rats also developed a preference for a CS+ flavor that preceded the ingestion of a Polycose solution by 10 min. This flavor conditioning, however, was not obtained in all experiments. Some CS flavors may be more effective than others in producing conditioned flavor preferences over a delay. Preference conditioning over a delay was facilitated when the rats had previously learned that the taste of the US (Polycose) was not associated with rapid caloric repletion; this was accomplished by giving the rats prior exposure to a Polycose + acarbose solution. Rats with such pre-exposure learned to prefer a CS + flavor that preceded by 10 to 60 min the consumption of a Polycose solution (without acarbose). The results demonstrate that calorie-based flavor preferences can be conditioned over a delay, but conditioning is influenced by the nature of the CS and US stimuli used.

Acarbose↗

PubMed1988

Polycose and sucrose appetite in rats: influence of food deprivation and insulin treatment.

Rats appear to have two different carbohydrate tastes, a sweet taste for sugars, and a "polysaccharide" taste for starch and starch-derived polysaccharides. The present study explored the possible functional significance of this dual taste system by comparing the effects of food deprivation and insulin treatment on the appetite for sucrose and Polycose. Food deprivation (24 h) produced comparable increases in the 5-min and 30-min intakes of Polycose and sucrose (1-8%) solutions in adult female rats. Polycose and sucrose intakes were also increased to a similar degree by insulin injections (1 unit/kg) during brief (3-min) one-bottle tests. In brief two-bottle tests, however, insulin treatment tended to shift the rat's preference from sucrose to Polycose. Chronic treatment with insulin increased the long-term intake of 30% Polycose and sucrose solutions, with the effect being more pronounced with Polycose. These findings demonstrate that energy deficit states enhance the appetite for Polycose as much as or more than the appetite for sucrose.

Animals↗

PubMed1988

Robust conditioned flavor preference produced by intragastric starch infusions in rats.

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.

Animals↗

PubMed1988

Carbohydrate appetite in rats: taste and postingestive factors.

Studies designed to elucidate the role of taste and postingestive factors in the rat's hyperphagic response to carbohydrate solutions are reviewed. Initial experiments revealed that polysaccharide solutions induce as much overeating as do sugar solutions, but that sugars and polysaccharides produce little or no overeating when presented in powder form. Although rats were found to be very attracted to the taste of polysaccharide solutions, as they are to sugar solutions, taste alone does not explain their overconsumption of these solutions. Several studies indicate that the postingestive actions of carbohydrates are also important determinants of carbohydrate appetite and intake. This is most clearly demonstrated by the conditioning of robust taste preferences using intragastric carbohydrate infusions.

Animals↗

PubMed1987

Carbohydrate taste preferences in rats: glucose, sucrose, maltose, fructose and polycose compared.

The taste preferences of adult female rats for solutions of five different carbohydrates were evaluated using brief (3-min) two-bottle preference tests. At the lowest concentration tested (0.03 molar) the order of preference was Polycose greater than maltose greater than sucrose greater than glucose = fructose. Whereas at the highest concentrations tested (0.5 or 1.0 molar) the preference order was sucrose greater than maltose greater than or equal to Polycose greater than glucose greater than fructose. Thus, at low concentrations starch-derived polysaccharides (Polycose) are more palatable to rats than are sugars. These findings are consistent with the hypothesis that rats have separate taste receptors for sugars and for starch-derived polysaccharides. The fact that maltose is the most preferred sugar at low concentrations is attributed to its stimulation of "polysaccharide" taste receptors.

Animals↗

PubMed1987

Carbohydrate-induced hyperphagia and obesity in the rat: effects of saccharide type, form, and taste.

Adult female rats were fed, in addition to chow and water, a carbohydrate source that differed in type (glucose, sucrose, or polysaccharide), form (32% solution, powder, or gel), or taste (very sweet, minimally sweet, or bitter). A control group was fed only chow and water during the 40-day experiment. The groups fed the glucose solution, sucrose solution, or one of three polysaccharide solutions (Polycose, maltose-dextrin 10, maltose-dextrin 42) all overrate and gained more body weight and fat than did the control group. The carbohydrate solution groups did not differ in their total caloric intake, weight gain, percent body fat, or basal insulin level. The polysaccharide groups, however, consumed more carbohydrate than did the sugar groups. The groups fed glucose, sucrose, or Polycose in powder form consumed less carbohydrate and total calories, gained less weight and fat, and had lower insulin levels than did the groups fed the saccharides in solution form. The powder groups did not reliably differ from the control group on these measures. Rats fed Polycose in solution form or in a solid gel form (32% Polycose + 1% agar) were similar in their carbohydrate intake, total caloric intake, weight gain, and percent body fat. Rats fed Polycose solutions that were minimally sweet (32% Polycose), sweet (0.2% saccharin + 32% Polycose), or bitter [0.05% sucrose octa acetate (SOA) + 32% Polycose] did not differ in their Polycose intake, total caloric intake, weight gain, or percent body fat. The results demonstrate that saccharide form is more important than saccharide type or taste in promoting hyperphagia and obesity in rats. The Polycose gel findings further indicate that it is the water of hydration, not liquidity that is responsible for the hyperphagia-inducing effect of carbohydrate solutions.

Animals↗

PubMed1987

Effects of SOA and saccharin adulteration on Polycose preference in rats.

Female rats were tested for their preference for a 32% Polycose solution, and for 32% Polycose solutions made bitter or sweet by adulteration with either 0.05% sucrose octa acetate (SOA) or 0.2% saccharin during 24 hr/day two-bottle tests. The rats preferred the saccharin-Polycose to the Polycose, the Polycose to the SOA-Polycose, and strongly preferred the saccharin-Polycose to the SOA-Polycose solution. Additional rats that were given only a Polycose or an SOA-polycose solution, in addition to chow and water, consumed similar amounts of solution, and consumed as much as did the rats given the saccharin-Polycose solution. Thus, while SOA adulteration reduces, and saccharin adulteration increases, the relative palatability of Polycose, they do not alter the animal's intake when only one solution is available. In a second experiment rats were given the choice between a 32% Polycose solution and pure Polycose powder, between an SOA-Polycose solution and Polycose powder, or between an SOA-Polycose solution and sucrose powder during both 30-min/day and 24-hr/day preference tests. During the initial short-term test the rats preferred the Polycose solution and, to a lesser degree, the SOA-Polycose solution to the Polycose powder, but they strongly preferred the sucrose powder to the SOA-Polycose solution. During the subsequent long-term test, however, the rats developed a preference for the SOA-Polycose solution over the sucrose powder. The mechanism responsible for this preference switch is not certain, but it may be related to the postingestive effects of the solution, and may also be responsible for the rat's hyperphagic response to carbohydrates in solution form but not in powder form.

Animals↗

PubMed1987

Oral versus postingestive origin of polysaccharide appetite in the rat.

Previous studies have revealed that rats consume substantial amounts of polysaccharide solutions, even if the solutions are made bitter with the addition of sucrose octa acetate (SOA). The present experiment used the gastric sham-feeding preparation to determine if it is the orosensory or postingestive properties of polysaccharides that motivate rats to consume polysaccharide (Polycose) solutions. In Experiment 1, food deprived rats sham fed less of a 0.05% SOA + 32% Polycose solution than they did of a 32% glucose solution, but their SOA-Polycose intake was still considerable (44 ml/hr). The same rats refused to sham feed SOA-gum and SOA-sugar solutions that were similar to the SOA-Polycose solution in bitter taste, viscosity and free sugar content. In Experiment 2, rats sham fed as much of a 32% Polycose solution as they did of a 32% sucrose solution. Despite the gastric fistula, some of the ingested Polycose was absorbed as evidenced by an increase in the rats' blood glucose levels. The addition of acarbose, a drug that inhibits polysaccharide digestion, to the Polycose solution blocked the increase in blood glucose, but did not reduce the rats' sham feeding of the solution. These findings indicate that it is the orosensory (presumably taste) properties of polysaccharide solutions, not their postingestive effects, that initially attract rats to the solutions. The results question the assumption that polysaccharides are "tasteless" to animals.

Animals↗

PubMed1987

Hedonic response of rats to polysaccharide and sugar solutions.

The palatability of glucose, sucrose, maltose and polysaccharide (Polycose) was assessed by examining the consummatory response of nondeprived female rats to equicaloric or equimolar solutions of these saccharides. Both 30-min one-bottle acceptance and 30-min two-bottle preference tests were conducted: initial (3-min) lick rates were also recorded. At low molar concentrations the relative palatability of the saccharides was ordered as follows: Polycose greater than maltose greater than sucrose greater than glucose. At higher concentrations the rats were more attracted to sucrose than to Polycose; however Polycose remained more palatable than maltose at all but the highest concentration. In the one-bottle tests gram solute intakes varied as a function of percentage concentration, and was not influenced by saccharide type or solution osmolarity. The results along with other recent findings indicate that rats can taste starch-derived polysaccharides and find them quite palatable.

Animals↗

PubMed1987

Taste preference thresholds for Polycose, maltose, and sucrose in rats.

The taste preference thresholds of adult female rats for polysaccharide (Polycose), maltose, and sucrose were compared. The nondeprived animals were given 24-hr two-bottle preference tests (saccharide solution vs. water) and, starting at 0.008%, the saccharide concentration was increased daily. The rats first preferred the Polycose solution to water at 0.01% (0.0001 M), the maltose solution to water at 0.09% (0.0025 M), and the sucrose solution to water at 0.09% (0.0026 M). Thus, on a molar basis the rats' Polycose threshold was 25 to 26 times lower than their maltose and sucrose threshold. It was postulated that the low taste threshold for polysaccharides allows the rat to detect starch which, unlike sugar, is very low in solubility.

Animals↗

PubMed1987

Qualitative differences in polysaccharide and sugar tastes in the rat: a two-carbohydrate taste model.

A conditioned taste aversion paradigm was used to assess the qualitative similarities between the tastes of a polysaccharide (Polycose) solution and sugar solutions (sucrose, maltose, glucose, fructose). In Experiment I, three groups of female rats were water deprived and conditioned to avoid a 0.025 M Polycose, a 0.1 M sucrose, or a 0.1 M maltose solution by pairing solution consumption with a lithium chloride (LiCl) injection; in a control group water consumption was paired with the LiCl injection. The extent to which the experimental groups generalized their conditioned aversion to the other three solutions was then assessed. The Polycose-conditioned group avoided the maltose solution more than the sucrose solution, and the maltose-conditioned group avoided the Polycose solution more than the sucrose solution. The sucrose-conditioned group avoided the maltose and Polycose solutions to the same relatively low degree. In additional tests the three experimental groups showed similar aversions to a glucose solution, but only the sucrose-conditioned rats avoided a fructose solution. Rats in a second experiment also displayed relatively little cross-generalization between Polycose and sucrose aversions even though they were tested with different solution concentrations. Additional tests confirmed the results obtained in Experiment 1 with maltose, glucose, and fructose solutions, and also revealed that the sucrose-conditioned group, but not the Polycose-conditioned group avoided saccharin solutions. Neither Polycose- nor sucrose-conditioned groups avoided quinine, sodium chloride, or hydrochloric acid solutions. These results, along with other recent findings, suggest that rats have two types of "carbohydrate" taste receptors, one for polysaccharides and one for sucrose, which produce qualitatively distinct gustatory sensations.

Animals↗

PubMed1987

Influence of saccharide length on polysaccharide appetite in the rat.

The appetite of female rats for saccharides of different chain lengths was assessed in brief (5-min) one-bottle acceptance and two-bottle preference tests. The saccharides (and their lengths in glucose units) included glucose (1), maltose (2), maltotriose (3), maltooligosaccharide (4-8), maltopolysaccharide (average length 43), and Polycose (1 to 30+); 0.0125 and 0.025 molar solutions of these saccharides were tested. The results revealed that the rats' order of preference for these saccharides was as follows: maltooligosaccharide greater than maltotriose = maltose greater than glucose; and maltooligosaccharide greater than Polycose = maltopolysaccharide greater than maltose. Thus, as saccharide chain length increased from 1 to 4-8 glucose units palatability increased, but with further increases in chain length palatability declined somewhat. Previous findings have suggested that rats have a "polysaccharide" taste receptor and the present results indicate that the receptor is maximally (or near-maximally) stimulated by saccharides of 4-8 glucose units in length.

Animals↗

PubMed1987

Effects of gustatory deafferentation on Polycose and sucrose appetite in the rat.

Recent studies have revealed that rats are strongly attracted to the taste of starch-derived polysaccharides, and suggest that the taste receptors involved differ from those that respond to sucrose. The present study examined the possibility that different gustatory nerves mediate the rat's taste and appetite for polysaccharides and sucrose. This was accomplished by measuring the effects of selective gustatory nerve transection on the intake of Polycose and sucrose solutions in nondeprived female rats. Bilateral transection of the chorda tympani nerve produced comparable reductions in Polycose and sucrose intake, but bilateral transection of the glossopharyngeal nerve selectively reduced the intake of Polycose. Bilateral transection of the greater superficial petrosal nerve, and to a lesser degree, the pharyngeal branch of the vagus nerve, increased sucrose intake without affecting Polycose intake. These results indicate that while no single gustatory nerve mediates sucrose or polysaccharide taste, there is some specialization of function within the peripheral gustatory system. Combined bilateral transections of all four gustatory nerves produced the greatest reduction in solution intake, and reduced Polycose and sucrose consumption to the same degree. The suppressive effect was only partial, however, which indicates that relatively few intact taste receptors are required to maintain the rat's appetite for sugar and polysaccharide solutions.

Afferent Pathways↗

PubMed1987

Effects of anosmia on Polycose appetite in the rat.

Female rats made temporarily anosmic by intranasal treatment with zinc sulphate showed little or no reduction in their intake of a polysaccharide (Polycose) solution. This finding, along with the previous finding that experimentally-induced hypoguesia suppresses Polycose intake, indicates that olfaction is much less important than gustation in the mediation of polysaccharide appetite.

Animals↗

PubMed1987

Sham-feeding response of rats to Polycose and sucrose.

Adult female rats were fitted with gastric fistulas and maintained at 85% of their ad lib body weight. Their real-feeding (fistula closed) and sham-feeding (fistula open) responses to polysaccharide (Polycose) and sucrose solutions were measured during 30 min/day one-bottle tests. The rats consumed similar amounts of a 1% Polycose solution during real- and sham-feeding tests, but their sham-intakes of 4%, 16% and 32% Polycose solutions greatly exceeded their real-intakes of these solutions. Similar results were obtained with sucrose solutions. The rats sham-fed more Polycose than sucrose at the 1% and 4% concentrations, while their sham-intakes of the 16% and 32% Polycose and sucrose solutions were comparable. In subsequent two-solution sham-feeding tests, the rats preferred 1% Polycose to 1% sucrose, but preferred sucrose to Polycose at 4%, 16% and 32% concentrations. These preference results indicate that rats find Polycose more palatable than sucrose at low concentrations, but sucrose more palatable at high concentrations. In addition, the findings that the rats preferred 4% sucrose to 4% Polycose in the two-bottle test, but sham-fed more 4% Polycose than 4% sucrose in the one-bottle tests, suggest that sucrose is more "orally-satiating" than is Polycose. These results provide further evidence for qualitative differences in the tastes of sucrose and polysaccharide. They also indicate that the amount of solution sham-fed does not necessarily reflect the palatability of the solution.

Animals↗

PubMed1987

Influence of saccharin on Polycose, sucrose, and glucose intake and preference in rats.

The effect of adding 0.125% saccharin to 3% or 32% solutions of Polycose, sucrose and glucose on the fluid intake and preference of adult female rats was examined. In Experiment 1, the rats consumed more of a 3% Polycose + 0.125% saccharin solution (P + s) than of either a 3% Polycose or 0.125% saccharin solution; similar results were obtained with sucrose + saccharin (S + s) and glucose + saccharin (G + s) solutions. The polydipsic effects of the P + s, S + s, and G + s solutions were comparable (225 to 278 ml/day). Adding saccharin to 32% Polycose, sucrose, or glucose solutions did not increase solution intake. In two-solution preference tests, though, the rats preferred the 32% Polycose + saccharin and 32% glucose + saccharin solutions to 32% Polycose and 32% glucose solutions, respectively. Saccharin did not reliably affect the preference for the 32% sucrose solution. In Experiment 2, the preference for 3% carbohydrate solutions was assessed using two-solution tests. The rats preferred 3% sucrcose to 3% Polycose or 3% glucose; they also preferred 3% Polycose to 3% glucose. When saccharin was added to the solutions, the rats displayed equal preferences for the S + s and P + s solutions, and for the P + s and G + s solutions but they strongly preferred the S + s to the G + s solution. Recent findings suggest that polysaccharides such as Polycose taste qualitatively different from sucrose and saccharin to rats, i.e., have a "nonsweet" taste.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗