A Refined Saccharomyces Cerevisiae-Induced Pyrexia Model In Rats For Specific Antipyretic Preclinical Screening

Wireless measurement of rectal temperature during exercise: Comparing an ingestible thermometric telemetric pill used as a suppository against a conventional rectal probe.

Recreational users report that mephedrone has similar psychoactive effects to 3,4-methylenedioxymethamphetamine (MDMA). MDMA induces well-characterized changes in body temperature due to complex monoaminergic effects on central thermoregulation, peripheral blood flow and thermogenesis, but there are little preclinical data on the acute effects of mephedrone or other synthetic cathinones. The acute effects of cathinone, methcathinone and mephedrone on rectal and tail temperature were examined in individually housed rats, with MDMA included for comparison. Rats were killed 2 h post-injection and brain regions were collected for quantification of 5-HT, dopamine and major metabolites. Further studies examined the impact of selected α-adrenoceptor and dopamine receptor antagonists on mephedrone-induced changes in rectal temperature and plasma catecholamines. At normal room temperature, MDMA caused sustained decreases in rectal and tail temperature. Mephedrone caused a transient decrease in rectal temperature, which was enhanced by α(1) -adrenoceptor and dopamine D(1) receptor blockade, and a prolonged decrease in tail temperature. Cathinone and methcathinone caused sustained increases in rectal temperature. MDMA decreased 5-HT and/or 5-hydroxyindoleacetic acid (5-HIAA) content in several brain regions and reduced striatal homovanillic acid (HVA) levels, whereas cathinone and methcathinone increased striatal HVA and 5-HIAA. Cathinone elevated striatal and hypothalamic 5-HT. Mephedrone elevated plasma noradrenaline levels, an effect prevented by α-adrenoceptor and dopamine receptor antagonists. MDMA and cathinones have different effects on thermoregulation, and their acute effects on brain monoamines also differ. These findings suggest that the adverse effects of cathinones in humans cannot be extrapolated from previous observations on MDMA.

Simple SummaryThe study was performed in order to answer the question: should horses be cooled after not very intensive exercise? Thus, the efficiency of four different water cooling methods was studied in horses after medium-intensity effort for leisure horses under moderate air temperature. The water cooling methods used included spraying with cold water: (1) lower body parts, i.e., lower parts of legs; (2) upper body parts, i.e., back of the head and flanks; and (3) both lower and upper body parts. The control group was not treated with water. Water cooling was applied to 19 warmblood geldings immediately after the end of exercise and 10 and 20 min later. The internal and body surface temperatures were registered and analyzed. The water cooling methods used led to a decrease in rectal and body surface temperature. Applying cold water on lower body parts was only effective and can be recommended for practical use under the described conditions.Cooling a horse after intensive exercise under hot conditions is commonly recommended. The study aimed to analyze changes in the rectal and surface temperature of the horses subjected to various water cooling treatments. This followed medium-intensity exercise performed by leisure horses under moderate air temperature. The experiment involved a control group without water application, and three variants of water cooling applied to 19 warmblood geldings after medium-intensity effort. Cooling of lower, upper, and lower and upper body parts was performed. In each variant, the rectal and body surface temperatures were measured five times: before; immediately after; and 10, 20, and 30 min after effort. Using water cooling under the studied conditions did not influence a post-exercise decrease in the rectal temperature. The decrease in body surface temperature depended on the used variant of cooling down the horse. Cooling the limbs by pouring water several times changed the surface body temperature from 34.2 ± 0.37 °C to 32.0 ± 0.32 °C and was more efficient than the repeated application of cool water on both the upper and lower body parts, leading to a temperature change from 34.6 ± 0.26 °C to 33.2 ± 0.36 °C. Thus, the application of cold water on the limbs only is sufficient for cooling the horse after medium-intensity exercise under moderate air temperature (about 24 °C).

Validity of prepartum changes in vaginal and rectal temperature to predict calving in dairy cows

High dose of lipopolysaccharide pre-treatment prevents OVA-induced anaphylactic decreases in rectal temperature in the immunized mice

1. The present study was designed to investigate tolerance to several pharmacological effects of apomorphine. 2. Changes in blood pressure, heart rate, plasma noradrenaline levels, rectal temperature, respiratory rate and retching plus vomiting were compared after administration of apomorphine (200 micrograms kg-1, i.v. as a bolus) or saline at different time intervals (30, 120 and 720 min) in four groups of chloralose-anaesthetized dogs. 3. The first administration of apomorphine induced a significant decrease in blood pressure and rectal temperature, a marked rise in heart rate with no change in noradrenaline plasma levels or respiratory rate. Emesis occurred in 71% of the animals. 4. A second administration of apomorphine 30 min later failed to modify blood pressure or heart rate. In contrast, the magnitude of apomorphine-induced changes in blood pressure and heart rate was similar to that observed after the first administration when apomorphine was given 120 or 720 min later. 5. The apomorphine-induced decrease in rectal temperature evoked by a second dose of apomorphine was less marked when given 30 and 120 min after the first dose and unchanged when given 720 min later. 6. The number of animals exhibiting retching and vomiting was lower when apomorphine was reinjected after 30 min than when the time between two successive injections of apomorphine was 120 or 720 min. 7. These results show that tolerance to apomorphine involves its cardiovascular, hypothermic and emetic effects. The time course of tolerance to repeated injections of apomorphine is longer for its hypothermic than for its hypotensive or emetic effects. This suggests a tissue-specific regulation of D2 dopamine receptors to repeated injections of apomorphine.

The subject of the study were dogs divided into two groups according to body weight: up to 10 kg and from 10 kg to 30 kg. The aim of the study was to determine the dynamics of the post-mortem decrease in rectal and kidney temperature. The temperature was measured on both sites at the same time using a thermometer connected to a computer, under constant environmental conditions of the necropsy room. In these animals, a higher temperature in the kidneys persisted for the duration of the study. Comparative analysis between mean differences in kidney and rectal temperature in small and large dogs showed the greatest temperature amplitude in the group of small dogs, both for the kidney and the rectum. The greatest decrease in temperature, 1.2°C, was noted for the kidney in small dogs between 4 and 6 hours after death. Analysis of the dynamics of the decrease in kidney and rectal temperature for both weight groups combined, and the difference in temperature between the kidney and the rectum in the time intervals analysed showed that in the first two hours the difference between kidney and rectal temperature did not exceed 0.5°C. Two hours after death the difference in temperature between the two measurement sites was about 0.5°C after which time dropped below 0.5ºC.

In this paper the antipyretic effect of the Hydroalcoholic extract of leaves of Colocasia esculenta against Brewer yeast induced pyrexia model in Wistar rats of either sex was investigated. Colocasia esculenta (Apiaceae) is a tropical perennial plant. It contain flavonoids, alkaloids, apigenin, anthocyanin, carbohydrates, fiber, minerals, protein, fat, calcium and iron, Fever induced in the animal (rats) by the injection 15%w/v of brewer’s yeast suspension (10mg/kg according to body weight of rats) subcutaneously in the back below the nape of the neck. . After 18 hr. of Brewer’s yeast injection and rise in rectal temperature was recorded. The temperature of animal was recorded at 0, 1, 2, 3 and 4hr after drug administration. Paracetamol (100 mg/kg p. o.) was used as standard drug. The group received Hydroalcoholic extract 200mg/kg and 400mg/kg showed significant decrease in rectal temperature respectively as compared with the group received standard drug. All the values are expressed as mean ± standard deviation and analysed for ANOVA. Differences between controls, standard ant test groups were considered significant at P < 0.001 levels. . The Hydroalcoholic extract of Colocasia esculenta leaves (200mg/kg and 400mg/kg) possesses dose dependent, significant antipyretic activity against Brewer yeast induced pyrexia.
 Keywords: Antipyretic activity, ethanolic extract, Colocasia esculenta, Dunnet’s t –test, ANOVA.

The effects of fexofenadine on eosinophilia and systemic anaphylaxis in mice infected with Trichinella spiralis

The study medicine is a multi-ingredient formulation composed of various herbs. It is suggested for the treatment of pyrexia and pain, as stated in classical literature. The study was designed to assess the effectiveness of the experimental medicine in reducing fever and pain in several animal models used for experimentation. Rats at 150 and 300 mg/kg bw were tested for antipyretic effectiveness in the yeast-induced pyrexia model compared to paracetamol (70 mg/kg bw p.o). The efficacy of the tested formulation in relieving pain was assessed using an acetic acid-induced writhing test in mice at dosage of 300 and 600 mg/kg bw, whereas diclofenac sodium was used as the standard control at a dose of 15 mg/kg bw orally. The analgesic effects in rats were evaluated using Eddy's hot plate test. Test drug was administered at doses of 150 and 300 mg/kg bw, whereas buprenorphine was used as the standard control at a dose of 0.10 mg/kg via subcutaneous injection. Animals that received a high dose (300 mg/kg bw) of the medication showed a substantial (<0.001) decrease in rectal temperature 60 minutes after treatment, compared to the normal control group. The identical dosage also resulted in a decrease in rectal temperature at the 120-minute time point when compared to the normal control group, however this difference did not reach statistical significance. Both tested dosage levels exhibited analgesic effect in the acetic-induced writhing test, resulting in a reduction of writhes by 36.71% and 68.71% respectively, compared to the normal control. Therefore, based on the aforementioned discovery, it can be inferred that the tested formulation exhibits antipyretic and analgesic properties.

1. Noradrenaline, 5-hydroxytryptamine (5-HT), acetylcholine and tranylcypromine were injected or infused into the lateral ventricle of the ox. The effects of these drugs on heart and respiration rates, heat production, rectal, skin and hypothalamic temperatures and skin evaporative loss were measured when the animal was exposed to environmental temperatures ranging from -1 degrees C to +30 degrees C.2. Acetylcholine (0.001-2 mg) had no detectable effect on temperature regulation at 20 degrees C.3. In small doses (0.005-0.05 mg) 5-HT had no detectable effect. Larger doses (2-5 mg) given in a cold environment (-1 degrees C) also had no effect but the same doses given in warm environments (15-30 degrees C) caused increases in skin temperatures, skin evaporative loss and respiratory rate, and decreases in rectal and hypothalamic temperatures.4. Infusion of tranylcypromine (0.107 ml./min of a 1 in 50 solution) in a warm environment (20 degrees C) also caused a decrease in rectal temperature after a delay of 1-1(1/2) hr during which no effects were apparent.5. Noradrenaline (2 mg) had no effect on temperature regulation when injected into animals in a warm environment (30 degrees C). When injected (1 mg) into animals in a cold environment (-1 degrees C) shivering stopped and heat production and rectal and hypothalamic temperatures were decreased.6. It is concluded that intraventricular 5-HT and noradrenaline both cause a decrease in body temperature, and it is unlikely that central temperature regulation in the ox is mediated only by these two substances.

This study compared the effect of 5, 10 and 20 min of cold-water (14°C) immersion on rectal and muscle temperature and neuromuscular function. Twelve cyclists performed four cycling time-to-exhaustion trials in hot conditions (40°C and 40%rh), followed 25 min later by cold-water immersion for 5, 10 or 20 min or 20 min in room temperature (24°C; control). Rectal temperature was measured continuously, and muscle temperature was measured before, immediately after and 45 min after the time-to-exhaustion-test, as well as before and after water immersion. Sixty-second maximal voluntary isometric torque and isokinetic torque of the knee extensors were measured before, immediately after and 55 min after time-to-exhaustion-test. A greater rate of decrease in rectal temperature was observed in all water immersion conditions 45–80 min after time-to-exhaustion-test compared with control. Compared with control, muscle temperature 45 min after time-to-exhaustion-test was lower for all water immersion conditions; however, muscle temperature was lower for the 10- and 20-min conditions compared with 5 min. Isometric torque measured 55 min after time-to-exhaustion-test was lower for all conditions. Isokinetic torque was lower for all conditions immediately and 55-min post-time-to-exhaustion-test. Of the durations measured, 5 min of cold-water immersion appeared as the most appropriate duration for reducing rectal temperature but limiting decreases in muscle temperature.

Effects of the enkephalin analogue FK33-824 on rectal temperature and respiratory rate in male mice

Physical stimulation of rat pups, of the type normally received from the mother, has been shown to regulate several behavioral and physiological systems in the young. The present paper describes a possible role of physical stimulation in an additional physiological system; the thermoregulatory system. Within a thermoneutral environment, physical stimulation produces a decrease in rectal temperature (Expt. 1). Even in an environment of increasing temperature, similar to that pups experience when in contact with the dam, physical stimulation attenuates an increase in rectal temperature (Expt. 2). The physiological mechanism of heat loss appears to involve ventilatory heat exchange resulting in convective and evaporative heat loss (Expts. 3, 4). Furthermore, physical stimulation continues to produce a decrease in rectal temperature throughout the preweanling period (Expt. 5). These results suggest that pups may not always have to resort to behavioral thermoregulatory mechanisms which require them to separate themselves from their mother. Rather, pups may be cooled, or at least a heat gain attenuated, by physical stimulation from the dam while maintaining contact with her.

Comparison of the effects of detomidine and xylazine on some α2-adrenoceptor-mediated responses in the central and peripheral nervous systems