An airtight and watertight closed chamber for intravital microscopy of the rat mesentery was developed. It incorporates an oxygen microelectrode and a thermistor for monitoring the local environment around the mesentery, as well as a heater for controlling the chamber temperature. This chamber provides an alternative to the superfusion method ...

Vocalization in the ultrasonic range (USV) has been reported to occur in young rodents in response to isolation, novelty, handling, and cold. Heretofore these calls have been known to occur only in alert, attentive, or emotionally aroused animals. These studies describe the emission of USV by comatose 9- to 10-day-old ...

1. Hibernating insectivore species (hedgehogs) and non-hibernating rodents (guinea pig and rat) were anaesthetized with 'equithesin' (a mixture of chloral hydrate, magnesium sulphate, and pentobarbitone sodium). 2. The physiological responses shown by the hedgehogs were similar to those observed in hedgehogs during a natural or cold-induced hibernation. 3. These responses ...

The effect of hypothermia on neuronal injury following permanent middle cerebral artery (MCA) occlusion in the rat was examined. Moderate hypothermia (body temperature 24 degrees C) was induced before MCA occlusion (0-minute delay group) in six rats, at 30 minutes in eight rats, and at 1 (seven rats), 2 (seven ...

BACKGROUND: Morbidity and mortality from bacterial sepsis remain high despite aggressive diagnostic and therapeutic intervention. Interleukin-1 has been implicated as mediator of the lethal effects of endotoxemia or bacterial sepsis. The current experiments were designed to evaluate the therapeutic efficacy of a human recombinant interleukin-1 receptor antagonist (IL-1ra) against polymicrobial ...

1. Five oxazolidines were synthesized by reaction of (-) ephedrine with aliphatic aldehydes. The aldehydes used were formaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde and trimethylacetaldehye. 2. These five oxazolidines were tested in rats for ephedrine-like pharmacological activity using the hyperthermia and anorexia models. 3. All five oxazolidines caused significant elevation of body ...

A novel method for the preparation of spheroids containing two types of cells (hetero-spheroid) has been successfully developed by using a collagen-conjugated thermo-responsive polymer, poly-N-isopropyl acrylamide, as a cell substratum. The hetero-spheroid was prepared by detaching the confluent monolayer composed of parenchymal and non-parenchymal rat liver cells at a temperature ...

The effect of the administration of three different concentrations (2.25, 1.13 and 0.56 mg/100 g body weight) of dimethoate on the urinary excretion of total, non dialysable and free hydroxyproline were studied in female albino rats. Compared to controls, the urine contents were significantly lower in higher concentration (2.25 mg/100 ...

To address whether a shift in hypothalamic thermal setpoint might be a significant factor in induction of hypoxic hypothermia, behavioral thermoregulation was examined in 7 female Sprague-Dawley rats implanted with radiotelethermometers for deep body temperature (Tb) measurement in a thermocline during normoxia (PO2 = 125 torr) and hypoxia (PO2 = ...

Richardson's ground squirrels [body temperature (Tb) 7 degrees C] survive prolonged stable hypothermia for three times as long as do rats (Tb 19 degrees C) (72 vs. 24 h). We have examined the changes in blood gases and acid-base state to assess whether these contribute to this difference in survival ...

Previous studies of total sleep deprivation (TSD) and paradoxical sleep deprivation (PSD) in the rat by the disk-over-water method have indicated that both produce changes in thermoregulation. In both kinds of deprivation, there was a progressive, large increase in heat production as indicated by measures of energy expenditure (EE). In ...

Using monoclonal antibodies, we previously detected two forms of transformation-associated proteins (TAPs), P64 and P68, in the rat kidney (6m2) cells transformed by the temperature-sensitive 110-murine sarcoma virus-Moloney-mutant. TAPs were secreted as glycoproteins by 6m2 cells grown at 33 degrees C, but not by 6m2 cells grown at 39 degrees ...

Previous studies have substantiated the antipyretic role played by extrahypothalamic limbic system (EXHY-LS) AVP during fever. Repeated attempts to elucidate other thermoregulatory functions of this hormone have failed. Circumstantial evidence, however, suggest central role for this hormone in thermoregulation under hypohydration. Hypohydration, hyperosmolarity and hypovolaemia induced upward shifts in temperature ...

The rat exhibits a reduction in movement in an open field following a 14-day course of forced swim stress at 12 degrees C. The decrease in movement is greater in rats receiving arecoline relative to those receiving saline prior to placement in the open field. The authors report that when ...

A simple mini-butane burner or "artificial rat," for calibration of small animal indirect calorimeters (modified Benedict and Haldane systems), was developed. Substitution of this burner for a live animal at regular intervals in an experimental protocol provides a means by which whole system function can be verified without disturbing respirometer ...

Rats with burn injuries demonstrate changes in thermoregulation including an upward shift of the set-point and reference temperatures with no change in sensitivity of the response in heat production to displacement of the temperature of the preoptic anterior hypothalamus. In the present studies, the response in plasma and urinary catecholamines ...

Past studies have found that the laboratory rat placed in a temperature gradient prefers temperatures that are markedly below its lower critical ambient temperature (LCT), whereas other rodents (e.g., mouse, hamster, and guinea pig) generally select thermal environments associated with minimal metabolic expenditure. To further study the rat's thermoregulatory behavior, ...

An extremely weak native light emission from rat liver nuclei was detected and studied using a highly sensitive single photon counting system. This emission is oxygen dependent and we attribute it to (per) oxidative processes. The effects of deuterium oxide and 1,4-diazabicyclo-[2.2.2] octane on the light emission suggests the possible ...

This study has analyzed variations in the number of nucleoli and nuclear bodies, as well as in their ultrastructural and cytochemical organization, after the osmotically induced activation of supraoptic nucleus (SON) neurons of the rat. The number of nucleoli and nuclear bodies and also the nucleolar size were determined on ...

Previous studies of rats subjected to total sleep deprivation by the disk-over-water method had shown a large increase in energy expenditure (EE) and an initial increase followed by a later decrease in body temperature (Tb). It had been proposed that the increase in Tb resulted from regulation toward a higher ...

We examined the diurnal rhythm of core body temperature in a strain of rats with an upregulated central muscarinic receptor system. The Flinders-Sensitive Line (FSL) was derived by selectively breeding rats for sensitivity to cholinergic agonists. When compared to control rats, the FSL rats showed a remarkably strong phase advance ...

A subnecrogenic dose of aflatoxin B1 (AFB1) was injected intraperitoneally into 8-10 wk old male rats of the Holzman strain. Cytoplasmic and sinusoidal eosinophilic bodies were seen in the liver which appeared at 30 h and reached a maximum at 48 h. Electron microscopically some of the cytoplasmic structures were ...

Previous studies of total sleep deprivation in the rat by the disk-over-water method had shown an initial rise in body temperature (Tb), a later decline to below baseline levels, and a progressive rise in energy expenditure (EE). To evaluate the role of changes in temperature setpoint in these results, the ...

Two experiments are reported here. First, the effect of lithium chloride (1, 2 and 4 mEq/kg IP for 21 days) on body weight was assessed in female and male rats. Food intake was measured in the rats treated with 2 mEq/kg. All the doses tested significantly increased body weight in ...

The purpose of this study was to assess the effect of genetic strain on the acute and long-term thermoregulatory response to the neurotoxicant trimethyltin (TMT) in rats of the Long-Evans (LE) and Fischer 344 (FCH) strains. In one study basic thermoregulatory responses including colonic temperature (Tc), metabolic rate (MR), evaporative ...

Metabolic adjustment was studied in male Wistar rats weighing 180-200 g with bilateral electrolytic lesions in the preoptic area which were acclimatized to a hot environment (34 degrees C, 30 rats) and to normal temperature (25 degrees C, 20 rats) for 60 days. Oxygen consumption at 34 degrees C and ...

Thermal degradation of heated chrysotile results in dehydration and changes in its crystalline structure. The impact of heat treatment at 150-1200 degrees C on the biological activity of chrysotile was tested in rats. Heating the chrysotile produced an increase in its biological aggressiveness measured in terms of animal survival rate ...

Electromagnetic radiation ranging from radiofrequency to microwave has classically been used to induce hyperthermia for treatment of cancer. This paper presents a new technique using near infrared radiation from an Nd:YAG laser in conjunction with surface cooling to induce hyperthermia in a rat tumor model. A CW Nd:YAG laser hyperthermia ...

In a first series of experiments rats were accustomed for two weeks to eat chow with capsaicin (250 micrograms: 1 g of food). After this habituation period, when free to choose, 3 rats out of 4 preferred eating the piquant chow. In a second series of experiments the rats had ...

1. In the rat variation of metabolic heat production is the principal effector of thermoregulation. There is a continuous relationship between ambient temperature and metabolic rat over the whole range of tolerable environmental temperature. The mechanism that controls metabolic rate is unknown; this paper reports an attempt to test whether ...

During hibernation the body temperature may fall to only a few degrees above 0 degree C. The heart of the hedgehog continues to function whereas the hearts of nonhibernating mammals stop beating. The present study was performed to investigate and compare the mechanical responses to hypothermia in rabbits, rats, and ...

Nutritional deprivation induced by increasing the litter size and subsequent dietary restriction results in rats having lower body weights and body lengths. Such undernourished rats have lower body temperatures as well as lower basal metabolic rate and nonshivering thermogenesis on a metabolic body weight basis; they also succumb on cold ...

Hydrolysis and acyl migration studies on L-3-(3-hydroxy-4-pivaloyloxyphenyl)alanine (1, NB-355), which produced long-lasting plasma L-dopa levels after oral dosing, have been conducted. Compound 1 exists as pure 4-O-pivaloyl-L-dopa in the solid state, but it converts rapidly to a mixture of the 3- and 4-O-isomers in solution. The rate of acyl migration ...

A turbidimetric method was developed for the quantitative estimation of the total alkaloids of kutaj bark (Holarrhena antidysenterica) in crude medicinal preparations and in the body fluids of man and rat. The alkaloids were colloidally precipitated with Dragendorff's reagent as complex salts of potassium iodobismuthate in extremely dilute solutions. The ...

Temperature-sensitive mutants (TSMs) of Mycoplasma pulmonis were produced by treating the wild-type strain with N-methyl-N'-nitro-N-nitrosoguanidine. Three TSMs were selected at 38 degrees C, as a restrictive temperature, and at 34 degrees C, as a permissive temperature. Two TSMs, UTCMI and UTCMII, were proven to be nonpathogenic but immunogenic. In addition, ...

The effect of body temperature during recovery from acute severe carbon monoxide (CO) poisoning on morbidity and mortality was investigated using an unanesthetized animal model. Levine prepared female rats were exposed to 2700 ppm CO for 90 min, displaying the usual hypothermia, hypotension and bradycardia. Body temperature in survivors was ...

1. Thermoregulation against cold exposure was studied in rats during pregnancy and early lactation, and compared with that of virgin rats. 2. When exposed to 0 degrees C for 60 min, rats which were within 24-48 h of parturition (pre-1-day rats) and those within 24 h of parturition (pre-0-day rats) ...

In earlier studies, rats totally deprived of sleep by a disk-over-water apparatus (TSD rats) had shown an increase in energy expenditure (EE) that could not be explained by increased motor activity or the metabolic expense of wakefulness. Excessive activation of a calorigenic mediator was a possibility, and norepinephrine-mediated sympathetic activation ...

The effect of ultrasound on placental transfer in the rat has been measured in vivo. At 15, 18, 21 and 22 days of gestation one uterine horn of each anaesthetized rat was exposed, after laparatomy, to ultrasound. The control horn was effectively shielded. Radio-labelled tracers were then injected into the ...

In order to investigate the response of rat pups to stress, 10-day-old rats (N = 10) were exposed to cold water (14 degrees C) for 5 min or to a control treatment (N = 10) for 5 consecutive days. On the sixth day when the rats were 15 days of ...

The purpose of this paper is to thoroughly review the literature and present a data base of the basic thermoregulatory parameters of the laboratory rat. This review surveys the pertinent papers dealing with various aspects of the thermal biology of the laboratory rat, including: metabolism, thermoneutrality, core and brain temperature, ...

The design and use of a miniaturized cryoprobe to allow reversible neural inactivation were investigated in the rat. Tissue temperature measurements around the cryoprobe in the cerebellum of anesthetized rats established that significant heat loss (lower than 20 degrees C) was localized within 1.5 mm of the cryoprobe tip. To ...

Spontaneously hypertensive (SH) rats have been shown to have elevated colonic temperatures when compared with normotensive Wistar-Kyoto (WKY) rats. In the present study, core temperatures of SH and WKY rats were compared using radiotelemetry temperature sensors implanted in the abdominal cavity. At an ambient temperature (Ta) of 25 degrees C, ...

Sauvagine is a 40 amino acid peptide, isolated from the skin of the South American frog, Phyllomedusa sauvagei, and structurally related to mammalian corticotropin releasing factor (CRF). Experiments with centrally or peripherally injected sauvagine produced dose-dependent hypothermia in rats kept at ambient temperatures of +4 degrees C and +22 degrees ...

Normal rat kidney cells (NRK) infected with a temperature-sensitive (ts) mutant of Rous Sarcoma virus (RSV) at the permissive temperature (33 degrees C) exhibit the morphological and growth characteristics of the transformed state. By the use of this system, it has been shown that the addition of rat fibroblast interferon ...

The present study examined the heat loss response of heat-acclimated rats to direct body heating with an intraperitoneal heater or to indirect warming by elevating the ambient temperature (Ta). The heat acclimation of the rats was attained through exposure to Ta of 33 or 36 degrees C for 5 h ...

This paper describes spontaneous post-mortem changes of peroxisomal staining in normal liver and kidney of rats and in human autopsy liver. At room temperature, regional staining loss is observed at 18 h after death in rat kidney, at 24 h in human liver and at 48 h in rat liver. ...

Intraperitoneal injection of the bombesin-like peptide litorin (0.5 ml of a 10(-5) M solution) led to a short-lived decrease in the body temperature (maximum of 0.9 degrees C) of laboratory rats. In contrast, immunization with litorin conjugated to bovine serum albumin (BSA) led to an increase in body temperature from ...

Thermoregulatory responses to an acute heat load with intraperitoneal heating (IH) or indirect external warming (EW) by increasing ambient temperature (Ta) were investigated with direct and indirect calorimetry in rats acclimated to environments of 24.0 degrees C (Cn), 29.4 degrees C (H1), and 32.8 degrees C (H2) for greater than ...

The circadian rhythm of body temperature (CTR) of male and female rats living at 23 degrees C, as well as their body temperature response to a yeast injection or to a 2-h exposure to 0 degree C, was investigated by telemetry. Young rats had a clear CTR with a mean ...