Role of Brown and Beige Adipose Tissues in Seasonal Adaptation in the Raccoon Dog ().

Brown adipose tissue (BAT) expresses uncoupling protein-1 (UCP1), which enables energy to be exerted towards needed thermogenesis. Beige adipocytes are precursor cells interspersed among white adipose tissue (WAT) that possess similar UCP1 activity and capacity for thermogenesis. The raccoon dog () is a canid species that utilizes seasonal obesity to survive periods of food shortage in climate zones with cold winters.

Seasonal Regulation of Metabolism: The Effect of Wintertime Fasting and Autumnal Fattening on Key Central Regulators of Metabolism and the Metabolic Profile of the Raccoon Dog ().

Investigations into the mechanisms regulating obesity are frantic and novel translational approaches are needed. The raccoon dog () is a canid species representing a promising model to study metabolic regulation in a species undergoing cycles of seasonal obesity and fasting. To understand the molecular mechanisms of metabolic regulation in seasonal adaptation, we analyzed key central nervous system and peripheral signals regulating food intake and metabolism from raccoon dogs after autumnal fattening and winter fasting.

Myo- and cardiotoxic effects of the wild winter mushroom ( Flammulina velutipes) on mice.

Rhabdomyolysis (destruction of striated muscle) is a novel form of mushroom poisoning in Europe and Asia indicated by increased circulating creatine kinase levels. Particular wild fungi have also been reported to induce elevated creatine kinase activities in mice. Flammulina velutipes (enokitake or winter mushroom) is one of the most actively cultivated mushroom species globally.

Expression of AMPK, SIRT1, and ACC Differs between Winter- and Summer-Acclimatized Djungarian Hamsters.

The wintering strategy of the Djungarian hamster (Phodopus sungorus) includes a naturally occurring decrease in food intake and body mass. Our aim was to investigate the conceivable role of the metabolic regulators, AMP-activated protein kinase (AMPK) and sirtuin 1 (SIRT1), in the seasonal adaptation of the Djungarian hamster. In addition, a rate-limiting enzyme in fatty acid synthesis and oxidation, acetyl CoA carboxylase (ACC), was studied.

The distribution of melanopsin (OPN4) protein in the human brain.

Until now, melanopsin (OPN4) - a specialized photopigment being responsive especially to blue light wavelengths - has not been found in the human brain at protein level outside the retina. More specifically, OPN4 has only been found in about 2% of retinal ganglion cells (i.e.

Effects of wintertime fasting and seasonal adaptation on AMPK and ACC in hypothalamus, adipose tissue and liver of the raccoon dog (Nyctereutes procyonoides).

The raccoon dog (Nyctereutes procyonoides) is a canid with autumnal fattening and passive wintering strategy. We examined the effects of wintertime fasting and seasonality on AMP-activated protein kinase (AMPK), a regulator of metabolism, and its target, acetyl-CoA carboxylase (ACC) on the species. Twelve farmed raccoon dogs (eleven females/one male) were divided into two groups: half were fasted for ten weeks in December-March (winter fasted) and the others were fed ad libitum (winter fed).

Physiological condition of bank voles (Myodes glareolus) during the increase and decline phases of the population cycle.

The dynamics of animal populations are greatly influenced by interactions with their natural enemies and food resources. However, quantifying the relative effects of these factors on demographic rates remains a perpetual challenge for animal population ecology. Food scarcity is assumed to limit the growth and to initiate the decline of cyclic herbivore populations, but this has not been verified with physiological health indices.

Transcranial light affects plasma monoamine levels and expression of brain encephalopsin in the mouse.

Encephalopsin (OPN3) belongs to the light-sensitive transmembrane receptor family mainly expressed in the brain and retina. It is believed that light affects mammalian circadian rhythmicity only through the retinohypothalamic tract, which transmits light information to the suprachiasmatic nucleus in the hypothalamus. However, it has been shown that light penetrates the skull.

Maintenance of skeletal muscle energy homeostasis during prolonged wintertime fasting in the raccoon dog (Nyctereutes procyonoides).

The raccoon dog (Nyctereutes procyonoides) is a canid species with autumnal fattening and prolonged wintertime fasting. Nonpathological body weight cycling and the ability to tolerate food deficiency make this species a unique subject for studying physiological mechanisms in energy metabolism. AMP-activated protein kinase (AMPK) is a cellular energy sensor regulating energy homeostasis.

Transcranial bright light exposure via ear canals does not suppress nocturnal melatonin in healthy adults--a single-blind, sham-controlled, crossover trial.

We investigated whether transcranial bright light (TBL) affects nocturnal melatonin and cortisol secretion in sham-controlled crossover trial. Young healthy adults were exposed in random order to 24 minutes of TBL or sham exposure via ear canals at 01:10 h. Saliva and urine samples were collected hourly between 21 h-03 h and 06 h-09 h.

Encephalopsin (OPN3) protein abundance in the adult mouse brain.

Encephalopsin belongs to the family of extraretinal opsins having a putative role in CNS tissue photosensitivity. Encephalopsin mRNA has earlier been localized in rodent brains, but expression and localization of the protein has not yet been reported. In this study, we aimed to define encephalopsin protein abundance and localization in the rodent brain.

Experimental infection of the deer ked (Lipoptena cervi) has no negative effects on the physiology of the captive reindeer (Rangifer tarandus tarandus).

The deer ked (Lipoptena cervi) is a haematophagous parasitic fly of cervids that spread to Finland in the early 1960's. Presently its northern distribution limit lies at approximately 65°N and it is gradually spreading northwards. In Finland the principal host species has been the moose (Alces alces), but the deer ked is about to establish contact with another potential host, the semi-domesticated reindeer (Rangifer tarandus tarandus) causing possible threats to reindeer health and management.

Rapid development of fasting-induced hepatic lipidosis in the American mink (Neovison vison): effects of food deprivation and re-alimentation on body fat depots, tissue fatty acid profiles, hematology and endocrinology.

Hepatic lipidosis is a common pathological finding in the American mink (Neovison vison) and can be caused by nutritional imbalance due to obesity or rapid body weight loss. The objectives of the present study were to investigate the timeline and characterize the development of hepatic lipidosis in mink in response to 0-7 days of food deprivation and liver recovery after 28 days of re-feeding. We report here the effects on hematological and endocrine variables, body fat mobilization, the development of hepatic lipidosis and the alterations in the liver lipid classes and tissue fatty acid (FA) sums.

Immunohistochemical definition of MT(2) receptors and melatonin in the gastrointestinal tissues of rat.

The gastrointestinal tract of vertebrate species contains melatonin, which participates in several physiological functions. Some of these effects are mediated via specific membrane receptors (MT(1) and MT(2)). In the present study, the distribution of the MT(2) receptor protein in the gastrointestinal tract was localized, and changes in MT(2) receptor density were observed in relation to the expected circadian changes in melatonin concentrations.

Effects of cold exposure, exogenous melatonin and short-day treatment on the weight-regulation and body temperature of the Siberian hamster (Phodopus sungorus).

Objective: To investigate how winter acclimatization (WA), exogenous melatonin (MEL) or endogenous melatonin (SD) affect plasma leptin and ghrelin concentrations and how leptin and ghrelin contribute to the regulation of different adaptations to wintering in the Siberian hamster.

Results: The plasma leptin and insulin and testicular testosterone concentrations were lower in the WA, MEL and SD groups, whereas the plasma ghrelin concentration was higher due to the WA treatment. In the treated hamsters, body temperatures during photo- and scotophase were lower throughout the study and torpor bouts were observed.

Long-term postinfarction melatonin administration alters the expression of DHPR, RyR2, SERCA2, and MT2 and elevates the ANP level in the rat left ventricle.

We investigated the effect of 2 wk continuous postinfarction subcutaneous melatonin supply on the expression of the rat left ventricular (LV) dihydropyridine receptor (DHPR), ryanodine receptor (RyR(2)), and sarco-endoplasmic reticulum Ca(2+)-ATPase2 (SERCA2), as they are fundamental proteins in cardiac contractility. The levels of plasma and LV atrial (ANP) and brain natriuretic peptide and melatonin were also measured, as was the expression of LV MT(1) and MT(2) receptors and pineal arylalkylamine N-acetyltransferase. Myocardial infarction (MI) was induced by ligation of the left anterior descending coronary artery and vehicle or melatonin (4.

The effects of wintertime undernutrition on plasma leptin and insulin levels in an arctic ruminant, the reindeer.

We examined the effects of prolonged undernutrition on plasma leptin and insulin levels and some serum protein metabolites in reindeer (Rangifer tarandus tarandus L.) during winter and spring. The reindeer (male <1 year) were fed their preferred winter feed, low-protein lichen ad libitum for 5 weeks, followed by 40% restriction of energy for 8 weeks and refeeding with high-protein pellets for 6 weeks.

Food deprivation in the common vole (Microtus arvalis) and the tundra vole (Microtus oeconomus).

Arvicolinae voles are small herbivores relying on constant food availability with weak adaptations to tolerate prolonged food deprivation. The present study performed a comparative analysis on the responses to 4-18 h of food deprivation in the common vole (Microtus arvalis) and the tundra vole (Microtus oeconomus). Both species exhibited rapid decreases in the plasma and liver carbohydrate concentrations during phase I of fasting and the decline in the liver glycogen level was more pronounced in the tundra vole.

Fasting in the American marten (Martes americana): a physiological model of the adaptations of a lean-bodied animal.

The American marten (Martes americana) is a boreal forest marten with low body adiposity throughout the year. The aim of this study was to investigate the adaptations of this lean-bodied species to fasting for an ecologically relevant duration (48 h) by exposing eight farm-bred animals to total food deprivation with seven control animals. Selected morphological and hematological parameters, plasma and serum biochemistry, endocrinological variables and liver and white adipose tissue (WAT) enzyme activities were determined.

Time course of changes in the expression of DHPR, RyR(2), and SERCA2 after myocardial infarction in the rat left ventricle.

Postinfarction left ventricular remodeling leads to the functional decline of the left ventricle (LV). Since dihydropyridine receptor (DHPR), ryanodine receptor (RyR(2)), and sarco-endoplasmic reticulum (SR) Ca(2+)-ATPase2 (SERCA2a) play a major role in the contractility of the heart, the aim of our study was to evaluate the time course of changes in the expression of these proteins 1 day, 2 weeks and 4 weeks after myocardial infarction (MI). Myocardial infarction was produced by ligation of left anterior descending coronary artery of the rat.

The effect of myocardial infarction on the synthesis, concentration and receptor expression of endogenous melatonin.

We examined the time course of changes in the synthesis and levels of endogenous melatonin and in the expression of MT(1) and MT(2) melatonin receptors 1 day, 2 and 4 wk after myocardial infarction (MI) in rats. MI was produced by ligation of the left anterior descending coronary artery. Transthoracic echocardiography was performed to characterize structural and functional changes after MI.

Adaptations to fasting in a terrestrial mustelid, the sable (Martes zibellina).

The aim of this study was to investigate whether the actively wintering Palearctic sable Martes zibellina has evolved physiological adaptations to tolerate nutritional scarcity. Sixteen farm-bred male sables were divided into a fed control group and an experimental group fasted for 4 days. The rate of weight loss in the sable was similar to other medium-sized mustelids.

Endocrinologic adaptations to wintertime fasting in the male American mink (Mustela vison).

The aim of this study was to investigate the endocrine response to wintertime starvation in the male American mink (Mustela vison) fasted for 16 hrs, 2 days, 3 days, 5 days, or 7 days (n =10 per group). After 2 days of fasting, the plasma leptin concentrations decreased, along with the triiodothyronine, testosterone, and progesterone levels, and the blood monocyte counts. Leptin also seems to trigger the response to fasting in mustelids by inducing immunosuppression and downregulation of the reproductive and thyroid axes.

The expression of MT1 and MT2 melatonin receptor mRNA in several rat tissues.

The mechanisms that mediate the various effects of melatonin in mammalian tissues are not always known. Therefore, the aim of this study was to investigate whether MT(1) and MT(2) melatonin receptors are expressed in certain tissues of the rat. The expression of MT(1) and MT(2) melatonin receptor mRNA was determined using a real-time quantitative RT-PCR method.

Endocrine response to fasting in the overwintering captive raccoon dog (Nyctereutes procyonoides).

The raccoon dog (Nyctereutes procyonoides) is an omnivorous canid utilizing the passive wintering strategy in the boreal climate. Farmed raccoon dogs (n=12) were randomly assigned into two study groups on 26 November 2003. Between 3 December 2003 and 27 January 2004, half of the animals were fasted for 8 weeks and plasma weight-regulatory hormone concentrations determined on 26 November and 30 December 2003 and on 27 January 2004.