Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Appetite”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 793 records · Page 44Linked to original sources
PubMed1998

Appetitive and consummatory male sexual behavior in Japanese quail are differentially regulated by subregions of the preoptic medial nucleus.

Central testosterone aromatization is required for the activation of both appetitive (ASB) and consummatory (CSB) male sexual behavior in Japanese quail. There are two major clusters of aromatase immunoreactive (ARO-ir) cells in the rostral forebrain; these outline the nucleus preopticus medialis (POM) and the nucleus striae terminalis (BST). We investigated the role of these nuclei in the regulation of ASB and CSB. Appetitive male sexual behavior was measured with the use of a learned social proximity procedure that quantified the time spent by a male in front of a window with a view of a female who was subsequently released into the cage, providing an opportunity for CSB. Males first acquired the response and then received bilateral electrolytic lesions aimed at the POM or BST, followed by retesting for ASB and CSB. Brain sections were stained for ARO-ir, and lesions to the two ARO-ir cell groups were quantitatively characterized. Lesions damaging the POM completely abolished CSB and also significantly decreased ASB. Lesions of the rostral BST had no effect on ASB, but moderately decreased CSB. Detailed anatomical analysis revealed that lesions of a subdivision of the POM just rostral to the anterior commissure specifically impair CSB, whereas lesions that are more rostral to this subdivision induce a severe deficit in ASB. These data indicate that different subregions of the POM regulate ASB and CSB in a somewhat independent manner, whereas the BST is only important in the regulation of CSB.

Animals↗
PubMed2004

Peptide YY and appetite control.

Peptide YY (PYY) is an important gut hormone synthesized and secreted by the gastrointestinal tract. Peripheral administration of PYY(3-36), one of the circulating forms of PYY, is known to inhibit food intake. This anorexigenic effect is masked by stress inhibition of appetite, and it is therefore important for animals to be thoroughly acclimatised for PYY(3-36) to be effective. Evidence suggests that PYY(3-36) acts via the hypothalamic Y(2) receptor. Levels of the anorexigenic hormone PYY(3-36) are low in overweight volunteers and could provide an important therapeutic avenue in the quest to combat the obesity epidemic.

Animals↗
PubMed1998

Appetite suppression and weight loss after the cannabinoid antagonist SR 141716.

The effect of the cannabinoid CB1 receptor antagonist, SR 141716, on food intake and body weight was assessed in adult, non-obese Wistar rats. The daily administration of SR 141716 (2.5 and 10 mg/kg; i.p.) reduced dose-dependently both food intake and body weight. Tolerance to the anorectic effect developed within 5 days; in contrast, body weight in SR 141716-treated rats remained markedly below that of vehicle-treated rats throughout the entire treatment period (14 days). The results suggest that brain cannabinoid receptors are involved in the regulation of appetite and body weight.

Animals↗
PubMed2003

Lesions of the subfornical organ decrease the calcium appetite of calcium-deprived rats.

There are several indications that neurons in the rat's subfornical organ (SFO) are sensitive to internal calcium status. We investigated the role of the SFO in regulating calcium intake by comparing the consumption of 30 mM CaCl2 by rats with (a) lesions of >90% of the SFO, (b) lesions that left the SFO mostly intact but disconnected its rostroventral stalk, (c) misplaced lesions that spared most of the SFO, or (d) a sham lesion procedure. In one experiment involving calcium-replete rats, these four groups had similar CaCl2 intakes. In another experiment involving calcium-deprived rats, those with lesions of the SFO or its rostroventral stalk consumed less CaCl2 than did those with missed or sham lesions. The SFO therefore appears to play a role in the calcium appetite that accompanies calcium deprivation in rats, most likely through its rostroventral efferents, but it is not important for need-free calcium intake.

Animals↗
PubMed2006

Effects of neuropeptide Y on feeding microstructure: dissociation of appetitive and consummatory actions.

The effects of intracerebroventricular application of Neuropeptide Y (NPY) on licking microstructure for sucrose, saccharin, and water solutions were evaluated. In Experiment 1, NPY increased meal size for three sucrose concentrations (0.03 M, 0.3 M, and 1.0 M) by increasing licking burst number but not size and by extending meals more than four-fold in duration with a slow, sustained rate of ingestion in late phases of the meal. Results are consistent with the interpretation that NPY suppressed inhibitory postingestive feedback. Experiment 2 supported this conclusion. NPY significantly increased the number of meals initiated for water, 0.1% saccharin, and 1.0 M sucrose solutions, but meal size was only increased for 1.0 M sucrose. Therefore, NPY also increased appetitive feeding behaviors, but its consummatory effects were limited to caloric solutions. The results are discussed with regard to their potential to explain current discrepancies in the literature.

Analysis of Variance↗
PubMed1975

Effect of calories on appetite for palatable food in obese and nonobese humans.

Palatable food stimuli were presented to 11 obese and 11 nonobese male human subjects (in three experiments) 1 hr after ingestion of 900-calorie liquid lunches and (on separate days) indentically tasting 450-calorie liquid lunches of equal volume. Salivary responses to the presentation of the stimuli (i.e., appetite) by the nonobese were inhibited by the high-calorie meal, but those by the obses were less inhibited. Hunger ratings were unaffected by calories in either group. Food stimuli were rated as more appetizing by the nonobese after high-calorie meals, but not so by the obese. Parallels with animal findings suggest that salivary responses reflect lateral hypothalamic activity.

Appetite↗
PubMed2001

Influence of a combination of herbs on appetite suppression and weight loss in rats.

AIM: We evaluated the ability of a Chinese herbal formulation previously associated with weight loss to influence appetite and weight loss in a carefully controlled laboratory study performed on rats. As a secondary gain, results with this herbal formulation were compared with those from a commonly available phenylpropanolamine (PPA) compound. DESIGN: Eight rats were placed in each arm of a three-arm study, a total of 24 rats. All rats were gavaged with a 2-ml fluid volume containing no addition (control) or the two test substances (combined herbs or PPA) for the first 4 days of the week over 6 consecutive weeks; no gavages were given over weekends. Rats in the two-test groups were given a relatively low dose of the test substance for 3 weeks, followed by a higher dose over the next 3-week periods. Food and water intake were measured for 24-h periods over the ensuing week days. The average daily values for food and water intake for an individual rat were calculated on the basis of collected data over each 3-week period. The mean values for each rat obtained over the low- and high-dose periods comprised results from averaging at least 10 measurements. RESULTS: Average daily food intake was decreased only with the herbal formulation, not the PPA compound at the low and high doses. Both the PPA compound and the herbal formulation lowered water intake significantly at the low and high doses. Rats ingesting the herbal formulation at the lower dose had statistically significant lower daily body weight changes over the 3 weeks than those ingesting the PPA compound. At the higher dose, body weight changes for both agents were significantly less than the control, but not significantly different from each other. No evidence of toxicity was seen in the blood chemistries or after histopathological examination. CONCLUSIONS: Data collected on rats suggest that the herbal formulation examined might be a useful and safe combination to overcome the overweight state and obesity.

Animals↗
PubMed2005

Peptide YY, appetite and food intake.

Obesity is taking on pandemic proportions. The laws of thermodynamics, however, remain unchanged, as energy will be stored if less energy is expended than consumed; the storage is usually in the form of adipose tissue. Several neural, humeral and psychological factors control the complex process known as appetite. Recently, a close evolutionary relationship between the gut and brain has become apparent. The gut hormones regulate important gastrointestinal functions such as motility, secretion, absorption, provide feedback to the central nervous system on availability of nutrients and may play a part in regulating food intake. Peptide YY (PYY) is a thirty-six amino acid peptide related to neuropeptide Y (NPY) and is co-secreted with glucagon-like peptide 1. Produced by the intestinal L-cells, the highest tissue concentrations of PYY are found in distal segments of the gastrointestinal tract, although it is present throughout the gut. Following food intake PYY is released into the circulation. PYY concentrations are proportional to meal energy content and peak plasma levels appear postprandially after 1 h. PYY3-36 is a major form of PYY in both the gut mucosal endocrine cells and the circulation. Peripheral administration of PYY3-36 inhibits food intake for several hours in both rodents and man. The binding of PYY3-36 to the Y2 receptor leads to an inhibition of the NPY neurones and a possible reciprocal stimulation of the pro-opiomelanocortin neurones. Thus, PYY3-36 appears to control food intake by providing a powerful feedback on the hypothalamic circuits. The effect on food intake has been demonstrated at physiological concentrations and, therefore, PYY3-36 may be important in the everyday regulation of food intake.

Appetite↗
PubMed2005

Transcriptional involvement of protein kinase C-alpha isozyme in amphetamine-mediated appetite suppression.

Amphetamine (AMPH) is known as an anorectic agent. The anorectic action of AMPH has been attributed to its inhibitory action on hypothalamic neuropeptide Y (NPY), an appetite stimulant in the brain. The molecular mechanisms behind this anorectic action of AMPH are still unclear. This study investigated the possible role of protein kinase C (PKC) isotypes in this anorectic action. Results revealed that most PKC isotypes (alpha, betaII, gamma, delta, eta, lambda and zeta), except betaI and epsilon isotypes, were stimulated during a repeated treatment of AMPH. Among these stimulated isotypes, three isotypes (alpha, delta, lambda) were activated and expressed in a similar manner, while the other isotypes were expressed differently and specifically. To determine if PKCalpha was involved in the anorectic response of AMPH, the infusions of antisense oligonucleotide into the brain were performed 1 h before daily AMPH treatment in freely moving rats, and the results showed that PKCalpha knock down could block the anorectic response and restore NPY mRNA levels in AMPH-treated rats. These results suggest that PKC isotypes- (at least the alpha isotype), related modification of NPY gene expression in hypothalamus might play an essential role in the central regulation of AMPH-mediated feeding suppression.

Amphetamines↗
PubMed2000

Appetite and parasite.

Molecular techniques have dramatically advanced our knowledge of the mechanisms that regulate appetite and body weight, yet human obesity, a significant healthcare problem, still lacks an effective science-based treatment. Infectious agents, including worm parasites, seem capable of overwhelming these regulatory systems. Can the study of parasites extend our understanding of what makes animals feed?

Animals↗
PubMed1984

The clinical pharmacology of appetite suppressant drugs.

One way of gaining a greater understanding of the central mechanisms underlying hunger and the regulation of feeding behaviour in humans is to examine the actions and interactions on hunger and food intake of drugs with known or presumed pharmacological modes of action. To this end we have undertaken a number of studies which fall into three main categories: the mechanisms by which amphetamine anorexia is induced; the possible role of endogenous opioids in feeding; the action of amino acids thought to be involved in the regulation of feeding. In this field the potential for cross-fertilization between basic scientists working with laboratory animals and clinical scientists working with human subjects exists. For example, the clinical pharmacologist has been able to test out hypotheses on human subjects which could only have been developed using laboratory animals. Furthermore, using human subjects it is possible to extend the field of inquiry into an exploration of the subjective dimensions of appetite and hunger.

Animals↗
PubMed1981

Anorectic drugs and vitamin C: role in appetite and brain ascorbic acid in guineapigs.

The role of daily administration of anorectic drugs (fenfluramine, mazindol and diethylpropion) with or without Vitamin C supplement, in the appetite and brain ascorbic acid, had been investigated in guineapigs receiving a daily Vitamin C-deficient diet for 24 days. Food intake was reduced by diethylpropion in the scorbutic male and female guineapigs but to a smaller extent by fenfluramine or mazindol. Supplementary Vitamin C daily significantly inhibited the anorectic actions of these drugs. In relation to the brain ascorbic acid level in the scorbutic gunieapigs, the initial stable level of brain ascorbic acid was significantly reduced by fenfluramine in both sexes by day 24, (P less than 0.05). Both mazindol and diethylpropion did not cause such reductions in the initial brain ascorbic acid. The three anorectic drugs prevented the rise in brain ascorbic acid normally associated with supplementary Vitamin C. It appears that brain ascorbic acid level can make metabolic readjustment during anorexia caused by diethylpropion and mazindol but not that caused by fenfluramine in guineapigs.

Animals↗
PubMed1993

Influence of a high-fibre food (myco-protein) on appetite: effects on satiation (within meals) and satiety (following meals).

The effect of meals containing Quorn myco-protein or chicken upon satiety and satiation were investigated in 18 lean, healthy male and female subjects using a within-subjects design. Both meals were designed to be similar in every respect with the exception of dietary fibre content (11 vs 3 g). Following consumption of a lunch containing Quorn myco-protein (high fibre) subsequent energy intake at an evening ad libitum test meal was reduced by 18% (P < 0.001) when compared with the response to an isocaloric chicken-containing (low-fibre) lunch. Using the Universal Eating Monitor (a device which weighs continuously the portion of food being consumed) the within-meal effects of a lunch containing Quorn or chicken were investigated. This study showed that during consumption, Quorn elicited similar eating behaviour when compared to a chicken meal. Amount selected, overall eating rate and the decrease in motivation to eat did not differ between the Quorn and control conditions. These two studies show that Quorn (high-protein, dietary fibre combination) has a strong impact on late satiety, but is similar in its effects during and immediately after consumption. These data have clear implications for the use of Quorn myco-protein for the control of appetite and body weight.

Animals↗
PubMed1997

The influence of natural preference for tactile stimuli on appetitive learning in rat pups.

Stimuli of the same modality tend to be organized along a "natural preference scale." This study examined the ability of six- and nine-day-old rat pups to acquire appetitive learning, when the CS was one of two differently "naturally preferred" tactile stimuli (floor textures: rug and plywood). In Experiment 1, all pups showed a relative natural preference for the rug texture over the plywood texture. Pups conditioned on the plywood texture (exposed to a sibling pup as the US) showed a robust increase in preference for the conditioned texture whereas pups conditioned on the rug texture showed a different and more moderate pattern of acquisition. Developmental differences were found only in extinction of the conditioned response: six-day-old (but not nine-day-old) pups displayed extinction of the response over four trials. Experiment 2 indicated that preexposure to the rug CS prior to conditioning (latent inhibition) did not interfere with the learning process on the rug texture. Two major alternative explanations for the differential learning patterns are discussed: motivational and catecholaminergic influences on learning. The results suggest that natural preferences may modulate early learning and memory processes.

Age Factors↗
PubMed1982

Appetitive conditioning in neonatal rats: conditioned orientation to a novel odor.

These experiments document a form of early appetitive learning in rats obtained using classical conditioning procedures. Some of the special determinants of this conditioning are described, as well as ontogenetic changes in the effectiveness of training procedures. Learning was apparent when deprived 3- and 6-day old rats oriented to and maintained contact with a novel and normally aversive odor after this odor had been paired with oral infusions of milk (Experiment I). The effectiveness of the conditioning procedures depended on the temperature at which pups were trained (Experiment IB). Moreover, the reinforcing properties of milk infusions depended on deprivation (Experiment IC). This conditioned change in responsiveness to odor was specific to the odor that had been paired with milk (Experiment II) and was retained for at least 24 hr (Experiment III).

Age Factors↗
PubMed1983

Appetitive instrumental training in preweanling rats: I. Motivational determinants.

Two experiments tested learning and retention of preweanling rats (10, 15, and 23 days of age) with an appetitive T-maze spatial discrimination task, using 3 different reinforcers for training (Mother Alone, Mother + Milk, and Milk Alone). The hypothesis was that immature rats are prepared to select and generate effective hypotheses for learning in an environment bearing some similarity to the home nest prior to their exhibiting similar capacities in other contexts. In Experiment I, we found support for this hypothesis in that 10- and 15-day-old rats were able to acquire the maze task when reinforced with Mother Alone or Mother + Milk, but not when reinforced with Milk Alone. In Experiment II, we report that 23-day-old rats weaned at 19 days postpartum were better at learning the maze task with milk as the reinforcer than littermates raised until training with the dam. We hypothesize that the development of foraging strategies might be necessary for the expression of maze behaviors reinforced with milk alone.

Animals↗
PubMed1983

Changes in appetitive behavior in weanling-age rats: transitions from suckling to feeding behavior.

To help identify determinants of rat appetitive behavior during the weanling period, rat pups 17-32 days of age were studied in a Y-maze. One arm of the maze provided pups with the opportunity to suckle a lactating or nonlactating anesthetized female. The other arm always contained a familiar food, either liquid diet or ground laboratory chow. In some experiments the dam was separated from the food compartment by a thin gauze screen. In other tests maternal contact could be maintained in the feeding goal but suckling in that compartment was prevented by nipple involution. Age was the major determinant of choice, with more older animals choosing the food arm. Availability of maternal contact in the feeding compartment increased the percentage of rats that chose to feed by about 20% at all ages studied. Food quality, but not quantity, affected choice at each age, as did lactational status. Prior food, water, and maternal deprivation (2 or 24 hr) did not affect choice behavior at any age but did influence behavior in the goal box. These findings are discussed within the context of the changing demands faced by the rats during the weaning period.

Aging↗
PubMed1988

Ontogeny of polycose and sucrose appetite in neonatal rats.

Rat pups 3 to 15 days of age were infused with sucrose or Polycose solutions (.03 or .3 M) through oral cannulas and their solution intake, mouthing behavior, and general locomotor activity were recorded. Overall, the pups displayed similar ingestive responses to Polycose and sucrose. They discriminated between .3 M sucrose and water as early as 6-days of age, and between .3 M Polycose and water as early as 9-days of age. However, at the .03 M concentration the pups responded to Polycose before they responded to sucrose. The results confirm previous reports that rat pups have an unlearned preference for sucrose and demonstrate that a similar preference exists for starch-derived polysaccharides. The Polycose appetite displayed by the neonatal rats is consistent with results obtained with adult animals which suggest that rats have taste receptors for starch-derived polysaccharides as well as for sugars.

Aging↗