scholarly journals Diurnal Rhythm of Apolipoprotein A-IV in Rat Hypothalamus and Its Relation to Food Intake and Corticosterone

Endocrinology ◽  
2004 ◽  
Vol 145 (7) ◽  
pp. 3232-3238 ◽  
Author(s):  
Min Liu ◽  
Ling Shen ◽  
Yin Liu ◽  
Daisuke Tajima ◽  
Randall Sakai ◽  
...  

Abstract Apolipoprotein A-IV (apo A-IV) is a satiety protein synthesized in the small intestine and hypothalamus. To further understand the roles of central apo A-IV in the management of daily food intake, we have examined the diurnal patterns of hypothalamic apo A-IV gene and protein expression in freely feeding and food-restricted (food provided 4 h daily between 1000 h and 1400 h) rats. In freely feeding rats, the hypothalamic apo A-IV mRNA and protein levels fluctuated, with high levels during the light phase, peaking at 0900 h (3 h after lights on), and low levels during the dark phase, with a nadir at 2100 h (3 h after lights off). The daily patterns of the fluctuation, however, were altered in food-restricted rats, which had a marked decrease in hypothalamic apo A-IV mRNA and protein levels during the 4 h-feeding period of the light phase. Although corticosterone (CORT) secretion temporally coincided with the decreasing phase of apo A-IV in the hypothalamus, depletion of CORT by adrenalectomy significantly decreased, rather than increased, hypothalamic apo A-IV mRNA and protein levels. These results indicate that the diurnal expression of hypothalamic apo A-IV is regulated by factors other than the circulating CORT, for example, the reduced food intake and body weight in adrenalectomized animals. The fact that hypothalamic apo A-IV level and food intake were inversely related during the normal diurnal cycle as well as in the period of restricted feeding suggests that hypothalamic apo A-IV is involved in the regulation of daily food intake.

1991 ◽  
Vol 261 (2) ◽  
pp. R313-R322 ◽  
Author(s):  
E. K. Walls ◽  
A. E. Willing ◽  
H. S. Koopmans

To determine whether feeding-generated gut signals act in conjunction with intravenous nutrients to suppress food intake, nutrients were infused intravenously to dark-fed rats during different portions of the 12:12 h light-dark cycle. During 4-day test periods rats received 35.5-37 kcal/day of a solution containing 25% glucose-4.25% amino acids. Food intakes were reduced by 40.5 +/- 1.1 and 30.7 +/- 1.8 kcal or 110 and 87% of the calories infused in the dark (fed) phase over 8 and 12 h, respectively. When administered in the light phase while rats were fasted, 8- and 12-h infusions reduced food intake significantly less than in the dark: 21.3 +/- 1.1 and 19.6 +/- 0.7 kcal/day or only 57 and 55% of the infused calories, respectively. With 24-h infusions, as in previous studies, food intake was reduced by 24.5 +/- 2.1 kcal/day or 68% of the infused calories. These results suggest that gut signals generated by concurrent feeding act with intravenous glucose and amino acids to produce a more compensatory reduction in daily food intake.


2004 ◽  
Vol 180 (2) ◽  
pp. 283-286 ◽  
Author(s):  
S Asakuma ◽  
O Hiraku ◽  
Y Kurose ◽  
S Kobayashi ◽  
Y Terashima

Leptin suppresses food intake and increases energy expenditure in the hypothalamus. Rats consume most of their daily food intake during the dark phase of the diurnal cycle. Lactating rats have increased food intake, but the involvement of leptin in the regulation of food intake in this physiological condition is not well understood. The present experiment was carried out to determine the circadian pattern of leptin concentrations in plasma and cerebrospinal fluid (CSF) in relation to the feeding behavior of non-lactating and lactating rats.Female rats were maintained on a controlled lighting schedule (lights on between 0600 and 1800 h) and the food intake of lactating rats was two- or threefold higher than that of non-lactating rats. In both groups, food intake was three times greater in the dark phase (P<0.01) compared with the light phase. The plasma concentrations of leptin were lower (P<0.01) in lactating rats than non-lactating rats in both light and dark phases, but there were no differences in plasma leptin levels between light and dark phases. In contrast, and in both groups, the leptin concentrations in CSF were lower (P<0.01) in the dark phase than in the light phase. Leptin levels in CSF were lower (P<0.01) in lactating rats than in non-lactating rats. We conclude that a diurnal pattern of leptin levels within the brain (but not in plasma) reflects characteristics of feeding behavior in lactating and non-lactating rats.


2005 ◽  
Vol 288 (1) ◽  
pp. G48-G53 ◽  
Author(s):  
Ling Shen ◽  
Li-yun Ma ◽  
Xiao-fa Qin ◽  
Ronald Jandacek ◽  
Randall Sakai ◽  
...  

To further investigate the role of intestinal aplipoprotein A-IV (apo A-IV) in the management of daily food intake, we examined the diurnal patterns in apo A-IV gene and protein expression in freely feeding (FF) and food-restricted (FR; food provided 4 h daily for 4 wk) rats that were killed at 3-h intervals throughout the 24-h diurnal cycle. In FF rats, the intestinal apo A-IV mRNA and protein levels showed a circadian rhythm concomitant with the feeding pettern. The daily pattern of fluctuation of apo A-IV, however, was altered in FR rats, which had a marked increase in intestinal apo A-IV levels during the 4-h feeding period of light phase. In both FF and FR rats, increased plasma corticosterone (Cort) levels temporally coincided with the increasing phase of intestinal apo A-IV mRNA and protein expression. Depletion of Cort by adrenalectomy abolished the diurnal rhythm by decreasing the apo A-IV expression during the dark period but did not change the feeding rhythm. Exposure of adrenalectomized rats to consistent Cort level (50-mg continuous release Cort pellet) resulted in fixed apo A-IV levels throughout the day. These results indicate that intestinal apo A-IV exhibits a diurnal rhythm, which can be regulated by endogenous Cort independently of the light-dark cue. The fact that intestinal apo A-IV levels were consistent with the food intake during the normal diurnal cycle as well as during the cycle of 4-h feeding each day suggests that intestinal apo A-IV is involved in the regulation of daily food intake.


2001 ◽  
Vol 204 (11) ◽  
pp. 1947-1956 ◽  
Author(s):  
M. S. Johnson ◽  
S. C. Thomson ◽  
J. R. Speakman

SUMMARYTo determine whether mice were limited in their capacity to absorb energy during late lactation, we attempted to increase the energy burden experienced by a group of female mice during late lactation by mating them at the postpartum oestrus, hence combining the energy demands of pregnancy and lactation. These experimental mice were therefore concurrently pregnant and lactating in their first lactation, and were followed through a normal second lactation. In a control group, females also underwent two lactations but sequentially, with the second mating after the first litter had been weaned. Maternal mass and food intake were measured throughout the first lactation, second pregnancy and second lactation. Maternal resting metabolic rate (RMR) was measured prior to the first mating and then at the peak of both the first and second lactations. Litter size and litter mass were also measured throughout both lactations. In the first lactation, experimental mice had a lower mass-independent RMR (F1,88=5.15, P=0.026) and raised significantly heavier pups (t=2.77, d.f.=32, P=0.0093) than the control mice. Experimental mice delayed implantation at the start of the second pregnancy. The extent of the delay was positively related to litter size during the first lactation (F1,19=4.58, P=0.046) and negatively related to mean pup mass (F1,19=5.78, P=0.027) in the first lactation. In the second lactation, the experimental mice gave birth to more (t=2.75, d.f.=38, P=0.0092) and lighter (t=−5.01, d.f.=38, P&lt;0.0001) pups than did the controls in their second lactation. Maternal asymptotic daily food intake of control mice in the second lactation was significantly higher (t=−4.39, d.f.=37, P=0.0001) than that of the experimental mice and higher than that of controls during their first lactation. Despite the added burden on the experimental females during their first lactation, there was no increase in their food intake, which suggested that they might be limited by their capacity to absorb energy. However, control females appeared to be capable of increasing their asymptotic food intake beyond the supposed limits estimated previously, suggesting that the previously established limit was not a fixed central limitation on food intake. As RMR increased in parallel with the increase in food intake during the second lactation of control mice, the sustained energy intake remained at around 7.0×RMR.


2009 ◽  
Vol 6 (3) ◽  
pp. 480-487
Author(s):  
Baghdad Science Journal

The aim of this study was to assess the nutritional status for samples at the age of 17-15 years. These samples were taken from secondary schools and universities in Baghdad area, 123 of them were male and 261 were female. Data on weight, height and body mass index (BMI) were determined in each individual. Smaller sample of 215 individuals (male and female) from the original sample was taken in order to record their nutritional behavior and daily food intake during the 24 hours prior to the visit through personal meeting using special questionnaire. The results showed that the weight and the height were within the range of the people of neighboring Arab countries, who are in the same age. Beside 44.4- 55.95% of these samples were within the normal weight using body mass index. Percentages of obesity and overweight were between 43.5- 6.5% for male and female respectively. There was an increase in daily food intake in general for essential diet and energy indeed, as recorded in nutritional behavior. 67% of samples have their breakfast every day. There were 51% of the samples having snacks (additional meal) between the major meals everyday and 62% have beverages every day. Also high percentage of samples were having milk and its products, vegetables, fruits (as nutritional sources) every day and the percentages were 47%, 67%, 78% respectively. In general their nutritional behavior and daily food intake were within the limits which showed by American recommended daily dietary, still there was some incorrect nutritional behavior which need more education and learning about nutrition.


1980 ◽  
Vol 46 (5) ◽  
pp. 215-225
Author(s):  
Hiroyuki TOYOKAWA ◽  
Yuko MIYAKE ◽  
Eiji MARUI

1990 ◽  
Vol 68 (3) ◽  
pp. 591-595 ◽  
Author(s):  
D. J. Booth

Field experiments were conducted over the summer of 1983 to determine food-evacuation rate and measure stomach fullness of bluegill sunfish (Lepomis macrochirus). A combination of these data gave estimates of daily food intake of fish. Fish were captured and held in large holding pens in Lake Opinicon, Ontario, Canada, and periodically subsampled over 24 h to monitor changes in mean weight of stomach contents. Stomach-evacuation rates obtained in this way increased significantly with water temperature over the range 10–25 °C. However, variation in stomach-evacuation rate was considerable, reducing the utility of water temperature as a predictor of stomach-evacuation rate. It is suggested that the simple field methods employed here to estimate stomach evacuation and food intake are more useful in the estimation of daily ration than the more commonly employed laboratory-based methods.


1989 ◽  
Vol 256 (1) ◽  
pp. R181-R186
Author(s):  
A. Bado ◽  
M. J. Lewin ◽  
M. Dubrasquet

The brain and gut peptide bombesin has been reported both to stimulate gastric secretion and to induce satiety. To understand how the peripheral administration of bombesin affects food intake and whether gastric mechanisms are involved, a comparative study of the doses of bombesin active on gastric secretion, gastric emptying, and food intake was undertaken in cats provided with a gastric fistula and a denervated Heidenhain pouch. The smallest dose of intravenous bombesin that stimulated significantly basal acid secretion (20 pmol.kg-1.h-1) by the gastric fistula also enhanced meal-stimulated acid secretion by the Heidenhain pouch (+138%, P less than 0.01), delayed gastric emptying of a liquid protein meal (-30%, P less than 0.01), and suppressed food intake when the test meal was allowed to reach the stomach (-15%, P less than 0.01). Conversely, in sham-feeding experiments, the same dose of bombesin increased food intake (+35%, P less than 0.01). In full-day experiments conducted in nonfasted cats, bombesin decreased both the food intake in the 4-h period after the infusion and the daily food intake, whereas octapeptide cholecystokinin induced a transient satiety but did not decrease daily food intake. These results indicate that in cats the interaction of bombesin with "pregastric" mechanisms is not sufficient to induce satiety and that a relation could exist between the effects of bombesin on gastric secretion, emptying, and food intake. A single class of receptors might be involved in these peripheral effects of bombesin.


2000 ◽  
Vol 2000 ◽  
pp. 22-22
Author(s):  
N.D. Cameron ◽  
J.C. Penman ◽  
E. McCullough

Leptin is synthesised and secreted from adipocytes into the blood stream and transported to the brain, where it acts to cause a release of factors which can reduce food intake (Houseknecht et al., 1998). There are two murine mutations of the recessive gene coding for leptin which are associated with obesity. The Lepob allele determines synthesis and secretion of leptin, while the Lepdb allele determines responsiveness to leptin. In the Edinburgh lean growth experiment in pigs, selection for high and low daily food intake (DFI) has been practiced for seven generations in a Large White herd, which provides the experimental resource to determine if the correlated response in fat deposition is consistent with insufficient leptin production or with insensitivity to leptin.


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