Polymorphonuclear leucocyte (PMNL) migration and oedema induced by carrageenan in the pleural cavity and paw, respectively, of rats made hyper- or hypothermic by physical and chemical means have been investigated. In rats placed in a warm environment to produce a rise in body temperature, carrageenan caused a moderate but significant ...

Two potent stimuli for AVP release into the blood, hemorrhage and hypertonic saline, were evaluated for their antipyretic effects in the rat. Hemorrhage of 20% of estimated blood volume reduced brain temperature of febrile but not afebrile rats confirming earlier research in the sheep. Hypertonic saline was also antipyretic in ...

The present study was performed to clarify the role of the cremaster reflex in regulating the testicular function in rats. The impairment of cremaster reflex by bilateral dissection of the genitofemoral nerves resulted in a decrease of testicular weight and degenerative changes of the semeniferous tubules in the rats kept ...

Rats with obesity-producing, hypothalamic knife cuts were fed a high fat diet and placed in the cold (2 degrees C) for six days starting 3, 11, or 24 days after surgery. Between surgery and cold exposure, knife-cut rats consumed 90% to 122% more energy and gained more weight (32 +/- ...

Studies are being conducted with Fischer-344 rats to determine the inhalation toxicology of a respirable power of copper-zinc alloy. Phase I involved standardization of methods, characterization of aerosols, and exposures of rats in whole-body of nose-only systems to air concentrations of 100 mg Cu-Zn/Cu m, or 100 mg titanium dioxide/Cu ...

Severely burned patients are hypermetabolic within their thermoneutral zone (TNZ), where there are no thermoregulatory demands on heat production. The rat has been used as a model of postburn hypermetabolism without clear evidence that it behaves in a similar way. Male rats (400-500 g; n = 34-39) were placed as ...

A potential antidepressant activity and an antiserotonin action of Org 8282, delta (13b, 4a), 4a-carba-mianserin, was studied in mice and rats. Org 8282 did not affect the reserpine-induced hypothermia, hypoactivity and ptosis, did not modify the apomorphine-induced hypothermia and the TRH-induced hyperthermia in mice, did not change the motor stimulation ...

The febrile responses in rats to an intravenous injection of the bacterial endotoxin Salmonella typhosa were investigated under normally hydrated and dehydrated conditions. When endotoxin was injected intravenously into the dehydrated rats, a biphasic-patterned fever resulted, whereas in normal rats an intravenous injection of endotoxin did not induce fever. No ...

21-day pregnant rats show high tissular and plasmatic acetone concentrations when submitted to a 48-hr fast. This rise is, in fact, associated with an enhanced placental and fetal acetoacetate decarboxylase activity. We propose that acetone formation by the fetus could be a mechanism for pH maintenance and that acetoacetate decarboxylase ...

Adrenalectomized rats are hypersensitive to the hypothermic as well as hypnotic effects of phenobarbital. The exaggerated hypnotic response is more pronounced in the chronic (10 day) than the acute (1 day) adrenalectomized rat and is reversed by glucocorticoid replacement. The prolonged hypothermia to a hypnotic dose of phenobarbital occurs in ...

A full-body restraining device was constructed that permits the short-term recording of physiologic data (respiration, electrocardiogram, arterial blood pressure, and electroencephalogram) in unanesthetized rats. A plaster cast of a freshly killed 160 g rat was made and cut to yield a base and two side pieces. Using the assembled cast ...

The volume of nitrogen eliminated (VN2) and washout rate constant (k) during a 2-h period of O2 breathing in the rat was altered in response to changes in body temperature. VN2 and cardiac output (Q) were determined simultaneously on 3 groups of unanesthetized but restrained male rats at 3 different ...

A method for the preparation of whole-body sections suitable for autoradiographic and histochemical study is described. Radioactive calcium chloride or [14C]proline was injected into the abdominal cavity of a rat. Thirty-five minutes after injection of calcium chloride or 40 min after injection of proline the rat was frozen in a ...

Rat endogenous pyrogen (EP), prepared from the white blood cells of lipopolysaccharide-pretreated rats, produced a fever in both rabbits and rats. The effects of human, rabbit, and rat EP on the body temperatures of rabbits and rats were investigated to clarify differences in the febrile response to each kind of ...

Improvement of the cold resistance capacity of the mole rat (Spalax ehrenbergi, Nehring), a blind subterranean rodent, was achieved following subcutaneous melatonin administration. Melatonin-treated mole rats exhibited reduction both in initial body temperature (Tbo) and in the decrease of body temperature (delta Tb) after 6 hours of exposure to cold. ...

Administration of naloxone to morphine-dependent male and female rats produced a significant rise in both tail skin temperature and foot temperature with a subsequent fall in colonic temperature. The magnitudes of the skin temperature surges were similar in the two regions, with the elevation in foot temperature preceding the rise ...

We have investigated the effects of ischaemia on responses to a subsequent noxious stimulus in rats. Tail flick latencies to a noxious thermal stimulus were determined by immersing the tail in water at temperatures ranging from 39 to 49 degrees C. We then produced ischaemia by occluding the blood supply ...

Adjustments of the obligatory and regulatory thermogenesis upon heat acclimation (34 degrees C) and perchlorate treatment were observed in male rats. Resting oxygen consumption measured at neutral temperature was reduced, with respect to control, by 23, 27, and 34% in heat acclimated, perchlorate treated, and heat acclimated-perchlorate treated rats, respectively. ...

Rats reared from birth at 30 degrees C show a permanent deficit in body temperature regulation. To test the ability of heat-reared rats to respond to an adrenergic drive, carbon dioxide production was measured at five doses of noradrenaline in rats reared at either 20 or 30 degrees C. Noradrenaline-induced ...

Analbuminemic rats died within 18 h after a rapid decrease of body temperature whereas control Charles River, Wistar, and Sprague Dawley rats survived for 40 h, when the animals were kept at 5 degrees C without food. Five low molecular weight fractions obtained from Sprague Dawley rat sera were administered ...

Hyperthermia produced by handling becomes evident at the initial daily measurement if temperature is measured at a consistent time. This hyperthermia may be a learned effect occurring in anticipation of handling. In Experiment One male Wistar rats were either unhandled or had their temperatures measured daily in the dark or ...

The ability of rat serum to inactivate endotoxin (LPS) was assessed with the aid of the limulus amebocyte lysate assay. Following the addition of various amounts of endotoxin to normal serum the mixture was incubated for 1 hr at 37 degrees C and the residual endotoxin activity determined. One milliliter ...

Although decreased serum thyrotropin (TSH) concentration has been found to be part of the endocrine response pattern in rats exposed to microwaves and other stimuli, the response of individual endocrine organs was not activated simultaneously by a given irradiance. Therefore, analytical evaluation of the function of endocrine organs individually as ...

We have been monitoring the body temperature and relative activity of up to 24 rats at a time using a recently developed biotelemetry system (The Dataquest III; Mini-Mitter Company). Each cage is maintained in a constant temperature chamber at 27 C and is on a 12:12 hour light-dark cycle. In ...

Two days following a rat bite, a 3-month-old boy presented to the ED with a temperature of 40 C and several puncture wounds on his right hand. He died after a fulminating illness. Postmortem examination revealed endocarditis, interstitial pneumonia, hepatic and splenic congestion, and arthritis. Blood cultures revealed the presence ...

Effect of beta-adrenoceptor blockade on the changes in rectal temperature (RT), heat production (HP) and noradrenaline (NA) concentration in the submaxillary salivary glands (SMSG) of rats exposed to heat (45 degrees C) was studied. Propranolol (P) (15 mg/kg i.p.) decreased the tolerance to heat. The survival time of propranolol-treated (PT) ...

The effect of ambient temperature on the energy requirements of the lactating rat was investigated. Ambient temperature was maintained at 13, 20 or 25 degrees C during lactation, and digestible energy (DE) intake, milk output and energy balance were measured between 4 and 12 d post partum. Ambient temperature did ...

After acclimating individually housed male rats to temperatures of either 24.5 +/- 0.1 or 29.2 +/- 0.1 degrees C for 14 days, randomly paired animals from each group were acutely exposed (3 h) in series to experimental temperatures between 18.0 and 34.5 degrees C in a controlled environment room. Relative ...

The effects of sodium salicylate (SS) and indomethacin (INDO) on rectal temperature (RT) and on prostaglandin (PG) concentration in the anterior hypothalamus of nonfebrile rats exposed to ambient temperatures (AT) of 4 +/- 1 degrees C, 23 +/- 2 degrees C and 34 +/- 2 degrees C were investigated. In ...

A detailed study of the kinetics and magnitude of thermotolerance has been made using the endpoint of loss of vertebrae in the baby rat tail. A range of different priming treatments was used and for analysis each priming treatment (PT) was given in terms of the heat sensitivity of the ...

Digoxin pharmacokinetic parameters in acute heat-exposed male rats (AHE) maintained for 3 hours at 35 degrees C, and chronic heat-exposed rats (CHE) maintained at 35 degrees C for 4 weeks, were compared to control rats (C) maintained at 22 degrees C. Digoxin concentration in the plasma was measured by radioimmunoassay ...

The present study investigated the suitability of different substrates on aminophylline (AMPY)-induced thermogenesis in rats during cold exposure. Feeding of distilled water 60 min prior to cold exposure in two-day fasted rats resulted in the lowest total heat production and final body temperature in both saline- and AMPY-treated groups. Feeding ...

In rats, we tested the hypothesis that capsaicin desensitization reduces hypothalamic warm thermosensitivity. We locally heated and cooled the hypothalamus using water-perfused thermodes while observing thermoregulatory variables. In untreated rats, a small dose of capsaicin had profound effects on thermoregulation. However, desensitizing rats to capsaicin had no effect on hypothalamic ...

Cooling mother rats by means of sodium salicylate injections did not curtail the intervals between maternal contact bouts. To the contrary, the interbout intervals were prolonged, suggesting that the relief from hyperthermia is a necessary but not a sufficient condition for the reinitiation of pup contact by mother rats. The ...

Liver and brain mitochondrial ATPase activities in rats exposed to high ambient temperature. Acta physiol. pol., 1985, 36 (3): 185-192. Rat liver and brain mitochondrial ATPase activities were investigated after a single exposure (6 h) of the animals to temperatures of 21 degrees, 28 degrees and 37 degrees C. An ...

A noncompetitive enzyme-linked immunosorbent assay to measure rat hepatic triglyceride lipase (H-TGL) was developed. Antibodies to rat H-TGL were purified from goat antisera by immunoadsorption on an H-TGL-Sepharose 4B column. Routinely, Immulon 2 Removawell strips were coated with the purified antibody overnight at 4 degrees C. After blocking the wells ...

Two hours after i.p. administration of 2-cyclooctyl-2-hydroxyethylamine (CONH), 1-aminomethylcycloundecanol (CUNH), 2,3-dichloro-alpha-methylbenzylamine (DCMB), or 7,8-dichloro-1,2,3,4-tetrahydroisoquinoline (SKF64139), the hypothalamic and brain stem epinephrine (EPI) contents of rat brain were decreased. Depletions of brain EPI with these phenylethanolamine N-methyltransferase (PNMT) inhibitors reduced the rectal temperatures of rats at ambient temperatures of 8 and ...

The febrile responses of Sprague-Dawley rats to semi-purified human endogenous pyrogen were studied at a thermoneutral ambient temperature (26 degrees C) and in the cold (3 degrees C). It was found that while rats developed typical monophasic febrile responses at thermoneutrality, febrile responses were absent in the cold-exposed rats. Experiments ...

Neurotensin-producing perikarya and fibers have been identified in the ventral tegmental area of the rat, and recent microinjection studies indicate that neurotensin may function in the ventral tegmental area to regulate body temperature. In this study, the hypothermic response produced by intraventral tegmental injection of neurotensin was shown to be ...

The effect of eliminating afferent input from cutaneous thermoreceptors of the face and trunk on the ability of rats to regulate body temperature in cool environments was studied. Thermoregulatory ability in a cool environment was assessed first in a 25 degrees C environment and then during slow (20 min) and ...

ABRs and EEGs were recorded in anaesthetized rats during whole body hyperthermia. ABR amplitudes were decreased during warming, with little recovery as body temperature was lowered. The latencies of the ABR waves decreased with warming and increased with subsequent cooling. The major latency changes were in the later ABR waves. ...

Both positive and negative biological effects of microwaves on drug actions in rats exposed to 1-mW/cm2, 2,450-MHz microwaves have been reported by several investigators. We conducted dosimetry studies for seven different exposure conditions to determine whether these different results could be due to the rats having been exposed differently. They ...

1. Neural activity was recorded in hippocampal slices from euthermic chipmunks, hamsters and rats. 2. While recording the evoked potentials, the temperature of the Ringer's solution bathing the slice was varied by controlling the temperature of an outer chamber jacketing the recording chamber. 3. The temperature just below that at ...

The effect of temperature on the rates of ethylmorphine N-demethylation and ethoxycoumarin O-deethylation was studied with liver homogenates prepared from 1- to 120-day-old rats. Breaks at temperatures of 21.5-28.0 degrees C were observed in the Arrhenius plots of these reactions, differences being dependent mainly on age of the animals rather ...

Experiments were conducted using twin-well calorimetry to determine the averaged whole-body specific absorption rate (SAR) for rat carcasses exposed to 360, 700, 915, and 2,450 MHz CW radiation in an anechoic chamber. All exposures were done with the long axis of the rat in an E-polarization. Additional experiments were conducted ...

The thermal effects of rats which were pretreated with 5,7-dihydroxytryptamine to deplete hypothalamic 5-hydroxytryptamine (5-HT) or with a 5-HT receptor blocker to intrahypothalamic administration of cholecystokinin (CCK) were compared with those of control rats. The CCK-induced hypothermic response was attenuated by pretreatment of the rats with either hypothalamic 5-HT depletion ...

Temperature optimum of mannosyltransferase activity in liver microsomes is higher in trout than in rat, but this enzymatic activity for rat is higher than trout. Activation energies calculated for mannosyltransferase activity for trout and rat do not correlate with environmental temperature. For a given incubation temperature, Vm values for rat ...

Temperature dependency of homologous and heterologous protein synthetic cell-free systems reveals characteristic homeotherm and poikilotherm behavior depending on the source of the enzyme elongation factor 1 and not on any other protein synthetic components. The results for rat and Antarctic fish, when compared with previous studies in eurythermal fish and ...

We compared the development of thermoregulatory abilities of fatty (fa/fa) and lean (Fa/-) Zucker rats as they grew from two weeks to eight months of age. The rectal temperature of lightly restrained littermates was continuously recorded for 2-6 h, and at ages before body weights of fatty and lean pups ...

Effect of immobilization stress on the rat colonic temperature and metabolism was studied in a warm environment of 25 degrees C. Immobilization for 3 hr caused hyperthermia accompanied by increased oxygen consumption (VO2) in the warm controls. The hyperthermic effect of immobilization was accelerated after 1 week repetition of daily ...