Additive effects of lactation and food restriction to increase hypothalamic neuropeptide Y mRNA in rats

1997 ◽  
Vol 152 (3) ◽  
pp. 365-369 ◽  
Author(s):  
J P H Wilding ◽  
M O Ajala ◽  
P D Lambert ◽  
S R Bloom

Neuropeptide Y (NPY) is the most powerful appetite stimulant known, and rates of synthesis and release in the hypothalamus correlate closely with nutritional status. Pregnancy and lactation provide an excellent model of physiological hyperphagia. In this study the authors measured food intake, plasma glucose, insulin and luteinizing hormone (LH) and hypothalamic NPY mRNA in rats during pregnancy and in early and late lactation. The effect of food restriction (to 80% of control) during lactation was also studied. Pregnancy resulted in a modest increase in daily food intake over non-lactating controls (controls: 15·6±0·6 g, pregnant: 19·8±1·1 g, P<0·01) During lactation food intake increased dramatically to 355% of non-lactating levels by the 12th day. Insulin and glucose levels were unchanged in lactation, except in the food-restricted animals, when insulin levels were reduced to 49·5±18·4 pmol/l compared with 215±55 pmol/l (P<0·01) in lactating, non-restricted animals, and glucose was reduced to 3·7±0·2 mmol/l compared with 5·1 ± 0·2 mmol/l in non-restricted lactating animals. Hypothalamic NPY mRNA was unchanged in pregnancy, moderately increased after 5 days lactation (130±6·2% of control, P<0·01) and increased further at 14 days lactation (179 ± 14%, P<0·001). The greatest changes occurred in the animals who were food-deprived during lactation, when hypothalamic NPY mRNA levels reached 324 ± 44% (P<0·001) of non-lactating levels. Increases in hypothalamic NPY synthesis may be partly responsible for the increase in food intake seen in lactation, but unlike in food deprivation, the increase is not related to circulating insulin, suggesting involvement of other regulatory factors. Journal of Endocrinology (1997) 152, 365–369

2000 ◽  
Vol 279 (3) ◽  
pp. R1025-R1034 ◽  
Author(s):  
Yuwaraj K. Narnaware ◽  
Pierre P. Peyon ◽  
Xinwei Lin ◽  
Richard E. Peter

In mammals, neuropeptide Y (NPY) is a potent orexigenic factor. In the present study, third brain ventricle (intracerebroventricular) injection of goldfish NPY (gNPY) caused a dose-dependent increase in food intake in goldfish, and intracerebroventricular administration of NPY Y1-receptor antagonist BIBP-3226 decreased food intake; the actions of gNPY were blocked by simultaneous injection of BIBP-3226. Goldfish maintained on a daily scheduled feeding regimen display an increase in NPY mRNA levels in the telencephalon-preoptic area and hypothalamus shortly before feeding; however, a decrease occured in optic tectum-thalamus. In both fed and unfed fish, brain NPY mRNA levels decreased after scheduled feeding. Restriction in daily food ration intake for 1 wk or food deprivation for 72 h resulted in increased brain NPY mRNA levels. Results from these studies demonstrate that NPY is a physiological brain signal involved in feeding behavior in goldfish, mediating its effects, at least in part, through Y1-like receptors in the brain.


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.


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