Annual changes in body mass in captive Svalbard ptarmigan: role of changes in locomotor activity and food intake

1995 ◽  
Vol 165 (6) ◽  
Author(s):  
K. Lindg�rd ◽  
K.A. Stokkan ◽  
S. N�slund
Appetite ◽  
2008 ◽  
Vol 50 (2-3) ◽  
pp. 562
Author(s):  
P. Lattimore ◽  
A. Roefs ◽  
A. Jansen ◽  
A.-K Fett ◽  
N. Geschwind ◽  
...  

2020 ◽  
Vol 223 (21) ◽  
pp. jeb231993
Author(s):  
Kimberley J. Mathot ◽  
Eva M. A. Kok ◽  
Piet van den Hout ◽  
Anne Dekinga ◽  
Theunis Piersma

ABSTRACTMass regulation in birds is well documented. For example, birds can increase body mass in response to lower availability and/or predictability of food and decrease body mass in response to increased predation danger. Birds also demonstrate an ability to maintain body mass across a range of food qualities. Although the adaptive significance of mass regulation has received a great deal of theoretical and empirical attention, the mechanisms by which birds achieve this have not. Several non-exclusive mechanisms could facilitate mass regulation in birds. Birds could regulate body mass by adjusting food intake (dieting), activity, baseline energetic requirements (basal metabolic rate), mitochondrial efficiency or assimilation efficiency. Here, we present the results of two experiments in captive red knots (Calidris canutus islandica) that assess three of these proposed mechanisms: dieting, activity and up- and down-regulation of metabolic rate. In the first experiment, knots were exposed to cues of predation risk that led them to exhibit presumably adaptive mass loss. In the second experiment, knots maintained constant body mass despite being fed alternating high- and low-quality diets. In both experiments, regulation of body mass was achieved through a combination of changes in food intake and activity. Both experiments also provide some evidence for a role of metabolic adjustments. Taken together, these two experiments demonstrate that fine-scale management of body mass in knots is achieved through multiple mechanisms acting simultaneously.


Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Vanessa Oliveira ◽  
Kirthikaa Balapattabi ◽  
John J Reho ◽  
Sebastiao D Silva ◽  
Chetan N Patil ◽  
...  

A subset of Agouti-related protein (AgRP) neurons within the arcuate nucleus express angiotensin type 1a receptors (AT1A), and genetic ablation of AT1A in these cells disinhibits AgRP gene expression and attenuates energy expenditure (EE) in mice. To further understand the role of AgRP in metabolic control, and to establish relevant dosing schedules in this species, here we tested the effect of intracerebroventricular infusion (icv) of recombinant AgRP on metabolic functions in C57BL/6J male mice. First, we examined the effects of AgRP(82-132) (21 days, 1 or 10 nmol/d, icv) or artificial cerebrospinal fluid (aCSF) using metabolic cages. High dose AgRP reduced body mass (aCSF n=12, +0.8±0.6 vs 1 nmol/d n=14, +0.6±0.6 vs 10 nmol/d n=11, -1.5±0.5 p<0.05 g/21d), without affecting food intake (15.1±1.2 vs 14.1±1.1 vs 16.3±1.1 kcal/d) or digestive efficiency (85.2±0.5 vs 84.5±0.7 vs 85.1±0.6 %), but a significant reduction in energy efficiency (+3.8±2.0 vs +2.7±2.8 vs -5.9±2.2 p<0.05 mg/kcal) indicated increased total EE. Next, we examined the effect of AgRP(82-132) (14 days, 1 nmol/d, icv) using a multiplexed system (Promethion, Sable). AgRP had no effect on body mass (25.1±1.2, n=8 vs 26.7±0.5, n=8), overall body composition (by NMR), heat production (Weir, 24h: 0.485±0.015 vs 0.490±0.022 kcal/h), or respiratory exchange ratio (0.88±0.01 vs 0.89±0.01). AgRP increased total food intake (10.1±0.6, n=8 vs 11.9±0.5, n=8, kcal/d, p=0.03) through a synergistic effect on number of meals and median meal mass. We conclude that AgRP (1-10 nmol/d, 2-3 wk, icv) infusion causes subtle changes in feeding behavior without effect on digestive efficiency. In contrast, EE is paradoxically increased by AgRP when infused at a high dose (10 nmol/d). We postulate that these differences may reflect differential accessibility of the peptide to relevant feeding vs autonomic control regions of the hypothalamus when infused into the cerebral ventricles, and/or compensatory increases in EE secondary to changes in feeding behavior. Future studies to deconvolute the role of AgRP in the control of EE in mice will require site-specific delivery of the peptide to relevant target regions or manipulation of its receptor in those regions. Funding: HL134850, HL084207


1995 ◽  
Vol 146 (1) ◽  
pp. 71-79 ◽  
Author(s):  
T Boswell ◽  
P J Sharp ◽  
M R Hall ◽  
A R Goldsmith

Abstract The present study addresses the role of prolactin as a regulator of migratory fattening in European quail (Coturnix coturnix). Plasma prolactin levels in captive birds undergoing migratory fattening in an outdoor aviary and in the laboratory were measured by radioimmunoassay with an antibody raised against recombinant-derived chicken prolactin. No strong association between prolactin and migratory fattening was apparent, and prolactin levels were more closely related to daylength, with the highest concentrations being reached on long days. Plasma prolactin profiles were similar in intact and castrated male quail. Prolactin was secreted in a daily rhythm, with the highest concentrations occurring early in the photophase. However, when birds were food-restricted for 50 days during a migratory phase, there was no difference in fat deposition between birds food-deprived for the first half of the daily photophase compared with those deprived for the second half. Fattening was reduced in the food-restricted birds relative to ad libitum-fed controls, but there was no difference in plasma prolactin levels between the groups. Injections of ovine prolactin (4 mg/kg) significantly increased food intake and body mass of birds maintained on long days, but there were no differences in fattening between birds injected in the morning compared with those injected in the afternoon. Collectively, these results do not support a major role for prolactin in the regulation of migratory fat deposition in European quail. Journal of Endocrinology (1995) 146, 71–79


1986 ◽  
Vol 251 (2) ◽  
pp. R264-R267 ◽  
Author(s):  
K. A. Stokkan ◽  
A. Mortensen ◽  
A. S. Blix

Food intake (FI), feeding activity (FA), and body mass (BM) were recorded continuously throughout a 13-mo period in Svalbard rock ptarmigan kept under natural conditions of light and ambient temperature at Svalbard (79 degrees N). FI was persistently high from March until August, including the period when daylight is continuous, whereas it was low from November until January, when it is permanently dark. From August until November, BM doubled, while FI dropped to one-third. BM fell rapidly from mid-November until April despite a doubling of FI from February until March. From August until mid-November and from February until mid-April FA occurred mainly during the light period of the day. From late November until February and from mid-April until August intermittent FA occurred continuously. It is suggested that the seasonal changes in BM are not determined by FI alone but depend heavily on seasonal changes in locomotor activity as reflected in FA.


2020 ◽  
Vol 66 (1) ◽  
pp. 71-78
Author(s):  
Lev Bershteyn ◽  
Aleksandr Ivantsov ◽  
Aglaya Ievleva ◽  
A. Venina ◽  
I. Berlev

The aim of this study was to evaluate steroid receptors’ status of tumor tissue in different molecular biological types of endometrial cancer (EC), subdivided according to the current classification, and their colonization by lymphocytic and macrophage cells, taking into account body mass index of the patients. Materials and methods: Material from treatment-naive patients with EC (total n = 229) was included; the number of sick persons varied depending on the method used. The average age of patients was close to 60 years, and about 90% of them were postmenopausal. It was possible to divide the results of the work into two main subgroups: a) depending on the molecular biological type of the tumor (determined on the basis of genetic and immunohistochemical analysis), and b) depending on the value of the body mass index (BMI). The latter approach was used in patients with EC type demonstrating a defective mismatch repair of the incorrectly paired nucleotides (MMR-D) and with a type without characteristic molecular profile signs (WCMP), but was not applied (due to the smaller number of patients) in EC types with a POLE gene mutation or with expression of the oncoprotein p53. According to the data obtained, when comparing various types of EC, the lowest values of Allred ER and PR scores were revealed for POLE-mutant and p53 types, while the “triple-negative” variant of the tumor (ER-, PR-, HER2/neu-) was most common in POLE-mutant (45.5% of cases) and WCMP (19.4%) types of EC. The p53+ type of EC is characterized by inclination to the higher expression of the macrophage marker CD68 and lymphocytic Foxp3, as well as mRNA of PD-1 and SALL4. In addition to the said above, for WCMP type of EC is peculiar, on the contrary, a decrease in the expression of lymphocytic markers CD8 (protein) and PD-L1 (mRNA). When assessing the role of BMI, its value of >30.0 (characteristic for obesity) was combined with an inclination to the increase of HER-2/neu expression in the case of MMR-D EC type and to the decrease of HER-2 /neu, FOXp3 and ER expression in WCMP type. Conclusions: The accumulated information (mainly describing here hormonal sensitivity of the tumor tissue and its lymphocytic-macrophage infiltration) additionally confirms our earlier expressed opinion that the differences between women with EC are determined by both the affiliation of the neoplasm to one or another molecular biological type (subdivided according to the contemporary classification), as well as by body mass value and (very likely) the associated hormonal and metabolic attributes.


Author(s):  
Ana P. Sehn ◽  
Anelise R. Gaya ◽  
Caroline Brand ◽  
Arieli F. Dias ◽  
Roya Kelishadi ◽  
...  

AbstractObjectivesThe combination of sleep duration, television (TV) time and body mass index (BMI) may be related to the alteration of cardiometabolic risk. However, there are few studies that use these variables grouped, and showing the moderating role of age. This study aimed to verify if the combination of sleep duration, TV time and BMI is associated with cardiometabolic risk and the moderating role of age in this relationship in youth.MethodsCross-sectional study conducted with 1411 adolescents (611 male), aged 10–17 years. Sleep duration, TV time and BMI were assessed and grouped into eight categories. Cardiometabolic risk was assessed by a continuous metabolic risk score, including the following variables: low HDL-cholesterol, elevated triglycerides, dysglycemia, high systolic blood pressure, high waist circumference and low cardiorespiratory fitness. Generalized linear models were used to test moderation of age in the relationship between the eight categories of sleep duration/television time/BMI with cardiometabolic risk.ResultsCardiometabolic risk factor showed association with all overweight or obesity independent of sleep time and TV time. Age moderated the relationship between sleep duration/television time/BMI with cardiometabolic risk. This association was stronger in younger adolescents (11 and 13 years), indicating that individuals with inadequate sleep, prolonged TV time and overweight/obesity present higher cardiometabolic risk values when compared to 15-year-old adolescents.ConclusionOverweight/obesity, independently of sleep duration and TV time, is the main risk factor for cardiometabolic disorders in adolescence. When moderated by age, younger adolescents that presented the combination of risk factors had higher cardiometabolic risk.


Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1158
Author(s):  
Lizeth Cifuentes ◽  
Michael Camilleri ◽  
Andres Acosta

Sensory and motor functions of the stomach, including gastric emptying and accommodation, have significant effects on energy consumption and appetite. Obesity is characterized by energy imbalance; altered gastric functions, such as rapid gastric emptying and large fasting gastric volume in obesity, may result in increased food intake prior to reaching usual fullness and increased appetite. Thus, many different interventions for obesity, including different diets, anti-obesity medications, bariatric endoscopy, and surgery, alter gastric functions and gastrointestinal motility. In this review, we focus on the role of the gastric and intestinal functions in food intake, pathophysiology of obesity, and obesity management.


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