Hot flashes are a disorder of thermoregulation due to the lack of estrogens and are the most common and characteristic climacteric complaint. Hormone replacement therapy is the gold standard treatment but now its use is limited due to several side effects. Need therefore arises to search for non-estrogenic alternatives. It ...

The specialization of body shape to an individual's role within society represents a pinnacle of social evolution. Although commonplace among social insects, divergence in the body shapes of breeders and helpers has to date been documented in just one social vertebrate, the naked mole-rat, Heterocephalus glaber; an extraordinary species in ...

OBJECTIVES: The objective was to develop a novel animal model of burns in rats and pigs. METHODS: The model uses heat that is delivered via a radiant heater with an opening of 5 cm by 5 cm, set at 400 degrees C, for 20 seconds. An advantage of this model ...

3,4-Methylenedioxymethamphetamine (MDMA, ecstasy) is associated with increases in core body temperature (T(C)) and depressive mood states in users. Flinders Sensitive Line (FSL) rats represent a rat model of depression originally bred from Sprague-Dawley (SD) rats. They are more sensitive to both muscarinic and serotonergic agonists and have altered thermoregulatory responses ...

Since Black-tailed Tree Rats, Thallomys nigricauda, face variable thermal environments in their extensive range in southern Africa, variation in their physiological and behavioural responses to the wide range of ambient temperatures (T(a)s) was expected to play a role in the success and range of the species. Body temperature (T(b)) and ...

To understand the tail-suspension model to simulate weightlessness better, this study was to investigate the relationship of the amount of body weight supported by forelimbs between the tilt angles of rat in the model. Normal rat had at least two basic postures. One was standing or walking, in which the ...

The basic metrics of hypermetabolism have not been thoroughly characterized in rat burn injury models. We examined three models expected to differ in sensitivity to burn injury to identify that which group(s) exhibited the most clinically relevant metabolic response. Six and 12 weeks old male CD (6 week mCD and ...

We examined the effect of riluzole on expression of the central respiratory rhythm and the ability of neonates to autoresuscitate from hypothermic respiratory arrest using in vitro brainstem-spinal cord preparations of rats and hamsters. At a constant temperature of 27 degrees C, riluzole (5-200 microM) decreased the burst amplitude of ...

The potential involvement of the melanocortin system in the beneficial effects of heat application in rats submitted to activity-based anorexia (ABA), an analogous model of anorexia nervosa (AN), was studied. Once ABA rats had lost 20% of body weight, half of the animals were exposed to a high ambient temperature ...

The aim of this study was to design, implement and analyze a space-efficient setup for the whole-body exposure of unrestrained Wistar rats to radiofrequency (RF) electromagnetic fields at 900 MHz. The setup was used for 2 years in a cocarcinogenesis study and part of it for 5 weeks in a ...

Brief periods of neonatal asphyxia are frequently observed. Within the CNS, the hippocampus is known to be particularly vulnerable to the damaging effects of hypoxia/ischaemia. The hippocampus contains the highest concentration of both mineralocorticoid (MR) and glucocorticoid (GR) receptors and the balance between MR/GR activation influences cell birth and death. ...

Cardiac dysfunction contributes to heatstroke genesis, which can be ameliorated by whole body cooling. A comparative analysis using two-dimensional in-gel electrophoresis of cardiac protein patterns is performed in rat controls, untreated heatstroke rats, and whole body cooling-treated heatstroke rats. After the onset of heatstroke, animals display hypotension and altered cardiac ...

BACKGROUND: The nucleus raphe magnus (NRM) is involved in thermoregulatory processing. There is a correlation between changes in the firing rates of the cells in the NRM and the application of the peripheral thermal stimulus. Introduction: we examined the effect of reversible inactivation and excitation of NRM on mechanisms involved ...

OBJECTIVES: Hypothermia improves outcomes after cardiac arrest (CA), while hyperthermia worsens injury. EEG recovers through periodic bursting from isoelectricity after CA, the duration of which is associated with outcome in normothermia. We quantified burst frequency to study the effect of temperature on early EEG recovery after CA. METHODS: Twenty-four rats ...

Pro-inflammatory cytokines interleukin (IL)-6 and IL-1 beta can act in the brain (centrally) to cause fever. Sickness behaviors which accompany fever also appear to involve the central action of IL-1 beta. We injected species-homologous rat IL-6 and IL-1 beta directly into the brains of conscious rats to examine the effect ...

The central melanocortin system is a critical contributor to energy balance control. Melanocortin receptors (MC-Rs) are widely distributed throughout forebrain and caudal brainstem nuclei. To assess the contribution of hindbrain MC-Rs to the control of energy expenditure, the MC3/4R agonist melanotan II (MTII) was delivered to either the fourth ventricle ...

OBJECTIVE: Therapeutic hypothermia after cardiac arrest improves survival and functional outcomes, whereas hyperthermia is harmful. The optimal method of tracking the effect of temperature on neurologic recovery after cardiac arrest has not been elucidated. We studied the recovery of cortical electrical function by quantitative electroencephalography after 7-min asphyxial cardiac arrest, ...

We studied the effects of selective loss of capsaicin-sensitive primary sensory neurons on thermosensation and thermoregulation in rats. Neonatal capsaicin treatment in rats caused a remarkable decrease in the number of small-diameter neurons in the dorsal root ganglion (DRG) compared with their number in the control rats. Gene expression analysis ...

Small rodents with a large surface-area-to-volume ratio and a high thermal conductance are likely to experience conditions where they have to expend large amounts of energy in order to maintain a constant body temperature at low ambient temperatures. The survival of small rodents is thus dependent on their ability to ...

Rat serum or plasma creatine kinase (CK) activity is widely used to evaluate myopathic processes, to test the myotoxicity of different drugs, or to analyse the benefits of emerging gene therapies in some neuromuscular disorders. However, great variability is found in this determination. The aim of this study has been ...

PURPOSE: To determine whether the ocular surface inflammation in uveitis mimics or counteracts intraocular inflammatory pathways by directly comparing T-helper (Th) lymphocytes Th1 and Th2 markers in conjunctival and ciliary body expression in endotoxin-induced uveitis (EIU). This study used the following inflammatory markers: chemokine receptor, CC chemokine receptor 4 (CCR4), ...

Transient global ischemia (ISC) in rats and humans causes selective and delayed neuronal death in the hippocampal CA1 sector. It is clear from rodent studies that hyperthermia aggravates, whereas hypothermia lessens, this injury. In this study we sought to relate core (Tc) and brain (Tb) temperature, measured via telemetry probes, ...

BACKGROUND: Diabetes-prone (DP) congenic DR.lyp/lyp BioBreeding (BB) rats all develop Type 1 diabetes between 50 and 81 days of age, while DR.lyp/+ or DR.+/+ BB rats are diabetes resistant (DR). The DP rats display reduced weight gain prior to developing hyperglycemia, implying that metabolic events may precede diabetes onset. We ...

Invasive mammalian predators such as rats are now widespread on islands, but hypotheses about their effects have rarely been tested. Circumstantial evidence from New Zealand indicates that, when introduced to islands, Pacific rats (Rattus exulans) have negative effects on endemic plants, invertebrates, birds, and reptiles, including the tuatara (Sphenodon punctatus). ...

When rats are exposed to heat, they adapt themselves to the stressor with a wide inter-individual variability. Such differences in heat tolerance may be related to particularities in the hypothalamo-pituitary-adrenocortical (HPA) axis activation. To further this hypothesis, 80 rats instrumented with a telemetric device for abdominal temperature (Tabd) measurement were ...

Low resting metabolic rate (RMR) in subterranean rodents used to be considered as a physiological adaptation to cope with stresses of the belowground environment. In African mole-rats (Bathyergidae, Rodentia), RMR was reported to be independent of body mass. This deviation from a general mammalian pattern was considered a precondition for ...

Pharmaceutically induced metabolic down-regulation may be a useful therapeutic adjunct when tissue oxygen supply is restricted. We hypothesized that protein synthesis inhibition in a non-hibernating species should lower oxygen demand, resulting in aerobic metabolic rate depression at the whole animal level. We compared metabolic responses and measures of systemic oxygenation ...

Norway rats are widely distributed throughout diverse climates from the tropics to the arctic. As a result, the environmental air temperature experienced during postnatal life varies widely and should influence the development of body morphology and thermal preference. To quantify this relation, rats were housed from birth to adulthood in ...

OBJECTIVES: Hypothermia of 32 degrees C-34 degrees C induced after resuscitation from cardiac arrest improves neurologic recovery, but the optimal depth of cooling is unknown. Using a rat model, the authors tested the hypothesis that cooling to 35 degrees C between hours 1 and 24 after resuscitation would improve neurologic ...

This study aimed to assess the time needed by rats, which had not been previously transported, to acclimate to a new environment after 5 h of van transport, using physiological parameters as measures of acclimatization. Animal shipping boxes and transport van conditions were standardized to minimize stress factors that could ...

We propose a communicating-vessels system to measure body volume in live rats through water level detection by hydrostatic weighing. The reproducibility, accuracy, linearity, and reliability of this apparatus were evaluated in two tests using previously weighed water or six aluminum cylinders of known volume after proper system calibration. The applicability ...

This study investigated the roles of endotoxemia and heat-induced tissue damage in the pathology of heat stroke. In groups of eight, male Wistar rats were treated with heat exposure only (HE), or heat exposure with turpentine (T+HE), dexamethasone (D+HE), and turpentine and dexamethasone combined (TD+HE). The rats remained sedated for ...

The functional residual capacity (FRC) and airway resistance (R(aw)) of the rat were measured, using a newly designed body plethysmograph (BPG), the inner environment of which was maintained at body temperature and was water-vapor saturated. The subjects were anesthetized and tracheally intubated male Wistar rats (n = 15). After measuring ...

Based on observed phenotypic differences in growth and ACTH responses to stress in Sprague Dawley rats obtained from different vendors, we ran head-to-head comparisons on rats obtained from three different vendors, Harlan, Charles River, and Simonsen, with respect to baseline phenotypic differences and a metabolic feedback hypothesis of hypothalamo-pituitary-adrenal (HPA) ...

Perinatal asphyxia in mammals leads to iron accumulation in the brain, which results in delayed neurobehavioural disturbances, including impaired learning and abnormal alertness over their entire life span. The aim of this investigation was to verify our hypothesis that newborn rats, showing reduced normal body temperature, are protected against neurotoxicity ...

Clozapine, an atypical antipsychotic agent important for the treatment of schizophrenia, has marked inhibitory effects on sympathetic outflow to the thermoregulatory cutaneous circulation. In rabbits clozapine reverses ear pinna vasoconstriction induced either by administration of MDMA (3,4-methylenedioxymethamphetamine, ecstasy) or by exposing the animal to a cold environment. In rats, both ...

Otsuka Long-Evans Tokushima Fatty (OLETF) rats lack cholecystokinin-A receptor (CCK-AR) because of a genetic abnormality. We observed that body temperature homeostasis in response to changes in ambient temperature was deteriorated in OLETF rats, while the functions of the signal outputs from the hypothalamus to effectors were not impaired. Deteriorated homeostasis ...

We have previously demonstrated that old and young rats mount similar fevers after intraperitoneal (i.p.) LPS injection at a warm ambient temperature (Ta) of 31 degrees C, but not at a cooler Ta of 21 degrees C. LPS stimulates the synthesis and release of proinflammatory cytokines, particularly interleukin-1 beta (IL-1 ...

The intracerebroventricular injection of endothelin-1 (ET-1) induces fever and increases PG levels in the cerebrospinal fluid of rats. Likewise, the injection of IL-1 into the preoptic area (POA) of the rat hypothalamus causes both fever and increased PG production. In this study, we conducted in vivo and in vitro experiments ...

Fescue toxicosis is caused by consumption of toxins produced by an endophytic fungus, Neotyphodium coenophialum, in tall fescue [Lolium arundinaceum (Schreb.) Darbysh]. Microarray analysis was used to identify shifts in genetic expression associated with the affected physiological processes to identify potential targets for future pharmacological/toxicological intervention. Male rats (n = ...

The safety and efficacy of methylene blue (MB) coated indwelling jugular vein/cranial vena cava catheter made up of polyurethane material was tested in a rat model, receiving bacterial culture suspension of Pseudomonas aeruginosa, and Staphylococcus aureus. Daily blood samples were collected from the catheter and peripheral vein for bacterial culture. ...

PURPOSE: To verify the capability of rabbit and rat ciliary body to synthesize and secrete ceruloplasmin. METHODS: Isolated ciliary body (CB) was cultured in the presence of [35S]-methionine, and the incubation medium was processed for immunoprecipitation. Total RNA from CB was processed for RT-PCR, and the amplification products were sequenced. ...

The UDP-glucose:glycoprotein glucosyltransferase (UGT) is a central player of glycoprotein quality control in the endoplasmic reticulum (ER). UGT reglucosylation of nonnative glycopolypeptides prevents their release from the calnexin cycle and secretion. Here, we compared the fate of a glycoprotein with a reversible, temperature-dependent folding defect in cells with and without ...

The maintenance of a physiological body temperature during and early after surgical interventions in experimental animals such as rodents is often neglected. Therefore the positive influence of an adequate use of warming blankets (WB) on the rectal body temperature in rats was investigated during two different surgical interventions, with a ...

OBJECTIVE: We sought to examine high-intensity focused ultrasound (HIFU)-induced hyperthermia in the liver of a rat model to focally induce green-fluorescent protein (GFP). MATERIALS AND METHODS: A total of 25 Copenhagen rats were included in this study. Rats were divided into groups treated with an adenovirus coding for green fluorescent ...

Rod responses to brief pulses of light were recorded as electroretinogram (ERG) mass potentials across isolated, aspartate-superfused rat retinas at different temperatures and intensities of steady background light. The objective was to clarify to what extent differences in sensitivity, response kinetics and light adaptation between mammalian and amphibian rods can ...

Alertness was studied in adult male Wistar rats after neonatal critical anoxia applied under three different thermal conditions: (i) at physiological neonatal body temperature of 33 degrees C, (ii) at body temperature elevated to 37 degrees C, and (iii) at body temperature elevated to 39 degrees C (both during anoxia ...

Competing views persist concerning the functional significance of ultrasonic vocalizations (USVs) emitted by infant rats. One perspective holds that USVs result from an emotional state of fear and anxiety, the adult expression of which depends in part on forebrain mechanisms. Here the authors examine whether pups lacking forebrain input are ...

Activity-based anorexia (ABA) is considered an animal model of anorexia nervosa. In ABA, scheduled feeding in combination with voluntary wheel running leads to hyperactivity, reduced food intake, severe body weight loss and hypothermia. In this study it was investigated whether hyperactivity in ABA could be reduced by introducing a warm ...

Perinatal environment is an important determinant of health status of adults. We tested the hypothesis that perinatal ambient temperature alters sympathetic activity and affects body composition in adult life and that this effect differs between S5B/Pl (S5B) and Osborne-Mendel (OM) strains of rat that were resistant (S5B) or susceptible (OM) ...