Feeding-drinking interaction: Intake of salted food and saline solutions by rats.

Deprived 16 naive female Wistar albino rats of both food and water for 24 hr. and then received 25 combinations of 5 food conditions (no food, 0, .9, 1.8, or 2.7 gm. of NaCl/100 gm plain food) and 5 liquid conditions (no liquid, plain water, .9, 1.8, or 2.7% saline solutions). Each combination of food and liquid was presented for 2 hr. to measure intake of food and liquid. This was followed by a 22-hr recovery period of plain food and water until the next deprivation day began. All Ss were given all 25 conditions in sequences designed to balance possible residual effects. Results indicate: (a) as NaCl concentration in food increased, the amount of intake of water and various saline solutions increased; (b) the rate of increase was greatest for water; (c) when food was presented, water and less-concentrated saline solutions were drunk more, but when there was no food, .9 and 1.8% saline solutions were drunk more than water; (d) food intake was reduced by NaCl content in liquid; and (e) food intake was independent of NaCl concentration in food. Results are discussed in terms of the colligative property of NaCl and the capacity of the rat to concentrate urine. (French summary) (28 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nutrient intake and food group consumption of 10-year-olds by sugar intake level: the Bogalusa Heart Study

We studied the occurrence of nocturnal enuresis (bedwetting) after the age of 4 years, using a questionnaire in a well-defined population, the Finnish Twin Cohort, which consists of 11,220 subjects aged 33-60 years, including 1298 monozygotic and 2419 dizygotic twin pairs. Structural equation modeling techniques were used to estimate variance components to compare different genetic models. Females reported enuresis in childhood "often" in 3.4% (males in 4.0%) and "sometimes" in 5.7% (8.0%). As adults, females had experienced enuresis "weekly" in 0.3% (males in 0.2%) and "monthly" in 0.07% (0.1%). Those who had experienced enuresis in childhood had had "at least sometimes" enuresis as adults in 5.4% of males and in 5.5% of females. Among those who reported they never had experienced enuresis as adults, 70.8% of males and in 77.9% of females had never experienced enuresis in childhood. For enuresis in childhood, the probandwise concordance rate was 0.43 for monozygotic and 0.19 for dizygotic pairs, and in adults 0.25 and 0, respectively. The proportion of total phenotypic variance attributed to genetic influences (due to dominance) was 67% in males (95% confidence interval 57-76%) and 70% in females (61-78%) in childhood enuresis. In conclusion, nocturnal enuresis is common in childhood and rare in adulthood. Our results confirm the central role of genetic liability in enuresis.     

Influence of fasting and neuropeptide Y on the suppressive food intake induced by intracerebroventricular injection of glucagon-like peptide-1 in the neonatal chick

Recently, we have reported that central administration of glucagon-like peptide-1 (GLP-1) strongly decreased food intake of chicks. The aim of the present study was to elucidate whether suppressed food intake by central injection of GLP-1 would be modified by an appetite stimulant such as fasting and neuropeptide Y (NPY). Birds (2 days old) were starved for 3 or 6 h and then GLP-1 (0.03 microg/10 microl) or saline was injected by the intracerebroventricular (i.c.v.) route. Birds starved for 6 h ate significantly more food than those starved for 3 h, while irrespective of the time for fasting GLP-1 strongly inhibited food intake as rapidly as 10 min after i.c.v injection. The suppressive effect on food intake continued until 4 h after injection. Central administration of NPY (2.5 microg/10 microl) greatly enhanced food intake, but co-injection of GLP-1 (0.01, 0.02 or 0.03 microg/10 microl) decreased food intake in a dose-dependent fashion. Under GLP-1 (0.03 microg/10 microl) treatment, whether NPY modifies food intake of chicks in a dose-dependent manner was investigated by co-injection of graded levels of NPY (0.4, 1.0 and 2.5 microg/10 microl). GLP-1 completely inhibited the effect of NPY on food intake without a dose response. These results suggest that central GLP-1 may interact with NPY and may be the most potent inhibitor of food intake in the chicken.     

Reduction of isoniazid bioavailability in normal men by concomitant intake of food

The influence of food intake on the bioavailability of isoniazid (INH) has been examined in nine healthy male volunteers. INH was administered as a single oral dose, both in fasting state and together with a standardized breakfast. Numerous venous blood samples were obtained 5 min-6 hours after the INH ingestion, and the concentrations of unmetabolized INH in serum were assessed by spectrophotometry. The observations indicate that both the peak concentration and the total amount of INH absorbed are greatly reduced when the drug is ingested together with food. Hence it is recommended that, in the treatment of tuberculosis with INH, the drug should be given on an empty stomach. The data may also have some bearing on the use of INH for assessing acetylation rates and estimating dosages of hydralazine and related drugs.     

Relation of reward from food intake and anticipated food intake to obesity: A functional magnetic resonance imaging study.

The authors tested the hypothesis that obese individuals experience greater reward from food consumption (consummatory food reward) and anticipated consumption (anticipatory food reward) than lean individuals using functional magnetic resonance imaging (fMRI) with 33 adolescent girls (mean age = 15.7, SD = 0.9). Obese relative to lean adolescent girls showed greater activation bilaterally in the gustatory cortex (anterior and mid insula, frontal operculum) and in somatosensory regions (parietal operculum and Rolandic operculum) in response to anticipated intake of chocolate milkshake (vs. a tasteless solution) and to actual consumption of milkshake (vs. a tasteless solution); these brain regions encode the sensory and hedonic aspects of food. However, obese relative to lean adolescent girls also showed decreased activation in the caudate nucleus in response to consumption of milkshake versus a tasteless solution, potentially because they have reduced dopamine receptor availability. Results suggest that individuals who show greater activation in the gustatory cortex and somatosensory regions in response to anticipation and consumption of food, but who show weaker activation in the striatum during food intake, may be at risk for overeating and consequent weight gain. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Selective effects of naltrexone on food pleasantness and intake

The effects of 50 mg naltrexone on both pleasantness and intake of 10 common food items were investigated using a double-blind placebo-controlled study with 16 male volunteers. Rated food pleasantness was reduced significantly in the naltrexone condition compared with both controls (placebo and baseline). However, pleasantness ratings were not affected uniformly across foods, with sweetened, fatty, and high-protein foods being most affected. Changes in rated unpleasantness generally mirrored those for pleasantness, but evaluations of saltiness and sweetness were unaffected by naltrexone. Although total intake was reduced in the naltrexone condition, this was not significant compared with placebo. However, fat and protein intakes were significantly less following naltrexone. The effect of naltrexone on intake was also food dependent, but in this case intake of sweet foods was spared relative to other food categories. The apparent discrepancy between liking and intake data with sweet foods could be interpreted in terms of the likely influence of normal eating styles on food selection during a buffet-style meal, and may explain some contradictions in previous studies of this kind. The implications for understanding opioid involvement in food acceptability are discussed.     

Implications of fat replacement for nutrition and food intake

This article provides specifics on the development of a clinical track for faculty appointments at the University of Pittsburgh. The criteria to be used for appointment and promotion on the clinical track are discussed along with the practice requirements of 60 hours per term of participation in and responsibility for direct care of patients. The purposes of faculty practice are set forth along with the formation and functioning of a Faculty Practice Council which handles decisions related to faculty practice. Results of the first year after implementation of a clinical track showed that 64 per cent (18) of the faculty had met all of their faculty practice obligations; of the remaining 36 percent (10) who had not, a variety of circumstances were cited. The Income to the School of Nursing for faculty practice, although modest, has helped to highlight that practice is valued and an integral part of the faculty role.     

Somatostatin decreases food intake of rats and baboons.

Somatostatin is a peptide hormone found in the CNS and the gastrointestinal tract. It has the ability to modify a number of metabolic factors associated with food intake. The purpose of the 7 experiments reported here was to determine the effect of somatostatin on the intake of individual meals of 2 species, the rat (131 female Wistar, 20 male Wistar and Long Evans) and the baboon (4 male Papio cynocephalus). In one set of experiments, Ss received somatostatin (10 ng–2 μg/kg) or a control solution ip. There was a dose-dependent decrease of food intake relative to vehicle-injected controls. In subsequent experiments, these doses had no effect on water intake and did not cause a conditioned taste aversion. Findings suggest that somatostatin acts relatively selectively on food intake and probably does not induce nausea or illness. The administration of somatostatin into cerebrospinal fluid had no effect on food intake. Therefore, somatostatin apparently works peripherally to reduce food intake in both rats and baboons. (46 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Control of food intake in children by reinforcement of relevant verbal behavior.

Amounts consumed of 4 foods were recorded for each child in nursery school. 10 children were randomly selected for repeated sessions of verbal conditioning, which occurred shortly before snack time, and consisted of reinforcing the verbal behavior (food term) denoting the food selected for manipulation. The data give evidence that when positive reinforcement is associated with the verbal response denoting a food, then the consumption of that food increases. Conceptually, food can be considered a stimulus that sets up a class of responses, including verbal and eating responses. If the verbal response in that class is reinforced, hence strengthened, then the other responses of that class will be strengthened as well. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Induction of ob gene expression by corticosteroids is accompanied by body weight loss and reduced food intake

Genetic studies in mice have identified the ob gene product as a potential signaling factor regulating body weight homeostasis and energy balance. It is suggested that modulation of ob gene expression results in changes in body weight and food intake. Glucocorticoids are shown to have important metabolic effects and to modulate food intake and body weight. In order to test the hypothesis that these metabolic effects of glucocorticoids are linked to changes in the expression of the ob gene, ob mRNA levels were evaluated in rats treated with different glucocorticosteroids at catabolic doses and correlated to the kinetics of changes in body weight gain and food intake. Results from time course experiments demonstrate that adipose tissue ob gene expression is rapidly induced by glucocorticosteroids. This induction is followed by a concordant decrease in body weight gain and food consumption. These data suggest that the catabolic effects of corticosteroids on body weight mass and food intake might be mediated by changes in ob expression. Modulation of ob expression may therefore constitute a mechanism through which hormonal, pharmacological, or other factors control body weight homeostasis.     

Caloric regulation of food intake in man.

Investigated caloric regulation in normal 18-36 yr old human Ss on a liquid diet. In Exp I, 8 Ss failed to compensate for changes in the caloric density of a preload (.25-1.8 kcal/ml) by adjusting meal size within 1 meal or from 1 meal to the next. In Exp II, 15 Ss were required to ingest nothing but the liquid diet for 10-21 days. They were given adlib access to a standard liquid diet (1.0 kcal/ml) for 4-9 days followed by 4-14 days on a diluted diet (.5 kcal/ml). 9 Ss failed to regulate their caloric intake in the time allowed. 6 Ss failed to regulate their caloric intake in the time allowed. 6 Ss compensated dramatically for the caloric dilution by increasing both meal size and meal frequency. Regulation was slow to occur (2-5 days) and usually was not perfect (mean level of 87%). Results are discussed in the light of work with animals and man on the mechanisms controlling regulation of food intake. (30 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Leptin decreases food intake induced by melanin-concentrating hormone (MCH), galanin (GAL) and neuropeptide Y (NPY) in the rat

Recent evidence suggests that leptin reduces food intake (FI) by acting at the hypothalamic level. Leptin decreases hypothalamic neuropeptide Y (NPY), melanin-concentrating hormone (MCH) and galanin (GAL) gene expression in rats. The purpose of the present study was to test the hypothesis that leptin decreases FI by additionally modulating the action of NPY, MCH or GAL in the hypothalamus. Intracerebroventricular (i.c.v.) administration of NPY, MCH or GAL induced FI in satiated rats. A prior i.c.v. injection of leptin (4 microg) completely prevented the increase of FI either by MCH, GAL or NPY. These results suggest that modulation of post-synaptic actions of MCH, GAL and NPY is one of the mechanisms of leptin signaling in the hypothalamus.     

Independent effects of estradiol on water and food intake.

Conducted 6 experiments to examine the effects of estradiol on ingestive behaviors of guinea pigs. Estradiol treatment was found to reduce water intake independently of its actions on food intake and body weight. In the 1st experiment, minimum intake and body weight of 17 intact female guinea pigs coincided with rupture of the vaginal membrane, the estimated time of ovulation. In Exp II, injections of 3 μg of estradiol benzoate (EB)/day to 7 ovariectomized females significantly depressed food intake, water intake, and body weight, compared with 7 Ss that received oil injections. Reducing food rations to 30% below ad lib levels in Exp III by itself had no significant effect on drinking in ovariectomized Ss. In Exp IV, therefore, ovariectomized females were first placed on a food ration 30% below ad lib levels and then injected daily with either 3 μg of EB or oil. Compared with oil injections, these EB injections significantly reduced water intake, while food intake did not decline significantly. Findings indicate that estradiol operates through different mechanisms to affect water intake and food intake. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Immune and endocrine regulation of food intake in sick animals

The evaluation of the carcinogenic potential of pharmaceuticals is currently undergoing dramatic changes. For the past 25 years the regulatory expectation for agents intended for long term use has been that lifespan studies (usually lasting 2 years) in 2 rodent species be conducted. These studies take at least 3 years to plan, execute and interpret, and use over 1200 animals. It is now recognised that the quality of the information obtained from these studies is unreliable for prediction of carcinogenic risk to humans. Over the past 4 years, the International Conference on Harmonisation (ICH) has recommended changes in approaches to assessing the carcinogenic potential of pharmaceuticals. In future, only one long term rodent study will be routinely required (usually in rats), provided this is complemented with a short or medium term test in one of the emerging new models for carcinogenicity, such as transgenic mice or newborn mice. However, the relevance of these new models to human cancer and their use in risk assessment is still largely unknown and this situation must be kept under review as knowledge accumulates. A long term study in a second rodent species is still an option. Dose selection has also been improved inasmuch as there are now several alternatives to the use of the maximum tolerated dose (MTD). In the past, the use of the MTD, when the normal homeostasis of the test animals is disturbed, has been considered one of the major problems with the rodent carcinogenicity bioassay. However, one of the alternative end-points to the use of the MTD, i.e. the comparison of plasma concentrations in rodents and humans, must be viewed with caution. While this may contribute to limiting the high dose level for agents of very low toxicity, the concept should not be interpreted as signifying that plasma concentrations provide a sound basis for comparing the carcinogenic activity of agents in different species. Recognition of the 4 properties (genotoxicity, immunosuppression, steroid hormonal activity and long term tissue damage), at least one of which is associated with each of the pharmaceuticals known to be carcinogenic to humans, should focus more attention on a search for these properties in patients. Absence of these properties at clinically relevant dose levels indicates that a pharmaceutical is highly unlikely to be carcinogenic to humans.     

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

In 4 experiments, a total of 478 suckling Charles River rats were subjected to deprivation periods of 6-8 hrs. Intake following deprivation was greater in deprived than in nondeprived Ss but did not increase with increasing deprivation. Gastric loads of NaCl solutions depressed subsequent intake; 3% NaCl was more effective than .9% NaCl. Other gastric loads of varying osmotic and caloric values also depressed subsequent intake. In order of increasing effectiveness in depressing intake, the gastric loads were protein hydrolystate, heavy cream, water, milk, lactose, glucose, and corn oil. Effectiveness was unrelated to osmotic or caloric value of the load. Gastric fill and, possibly, some property of carbohydrate appeared to be important determinants of satiety in the S. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of drinking in the suppression of food intake by recent activity.

The standard activity-based anorexia procedure provides rats with access to a running wheel while restricting their access to dry food. This can produce reduced food intake and progressive weight loss. Using this procedure, in the present study (Experiment 1) the authors found changes in drinking patterns both in the period of high activity preceding food access and during the feeding period. Varying the procedure by providing wet mash (Experiment 2) or by prior adaptation to a drinking schedule (Experiment 3) prevented the self-starvation effect. These results indicate the importance of drinking when analyzing the effect of recent activity on food intake. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Increase in plasma leptin and Lep mRNA concentrations by food intake is dependent on insulin

The difference in pregnancy rates following intrauterine insemination (IUI) for 1 vs. 2 days in the periovulatory period has been reported as either inconsequential or favoring the use of two consecutive inseminations, 24 hours apart. Our study compared the monthly fecundity and cumulative probability of pregnancy in a large group of women (n = 123) undergoing controlled ovarian hyperstimulation and 1- or 2-day inseminations with donor sperm prepared from frozen-thawed samples. All patients underwent controlled ovarian hyperstimulation employing either clomiphene citrate in 217 cycles or human menopausal gonadotropin in 185 cycles. The choice of single or double insemination was decided by the day of the week each patient received human chorionic gonadotropin for ovulation induction. Approximately 80% of all the patients underwent both single and double insemination treatments during the 2.5-year study period. Ninety-three patients received single inseminations in 180 cycles, whereas 103 patients received double inseminations in 222 cycles. Nine clinical pregnancies were achieved in the 1-day group (5% per cycle, 9.7% per patient), while 39 pregnancies occurred in the 2-day group (17.9% per cycle, 37.9% per patient). Two and five spontaneous abortions occurred in the 1- and 2-day groups, yielding take-home baby rates of 3.9% per cycle (7.5% per patient) and 15.3% per cycle (33.0% per patient), respectively. The cumulative probability of conception over 15 cycles of treatment was consistently twice as high or higher for the 2-day group. The results of this study support the use of 2-day IUI treatment cycles when using frozen-thawed donor sperm.