Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0020672 (hypothermia)
 17,327 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The hypothermic response following intraperitoneal doses (6.25, 12.5, and 25 mg/kg) of cobaltous chloride was investigated in Swiss albino mice. The magnitude and duration of rectal temperature depression were dose related. In each case, maximal hypothermia was evident within 30 min after injection. Body temperature depression was noted 30 min after oral, subcutaneous, intraperitoneal, intravenous, and intracerebral administration of cobaltous chloride. Cobalt was most active when administered intracerebrally, suggesting a central component to the thermolytic response. Rectal temperature depression following cobaltous chloride was dependent on the ambient temperature. The time course of the effect of cobaltous chloride on rectal and cutaneous tail temperature was noted. Cutaneous tail temperature depression occurred throughout the rectal temperature response, suggesting that cobalt may decrease heat production. Pretreatment with atropine sulfate, hexamethonium bromide, or nicotine failed to modify the temperature response to cobalt. Chlorpromazine hydrochloride pretreatment resulted in a partial antagonism of cobalt-induced hypothermia, presumably through a mechanism other than cholinergic blockade.
 ...
PMID:Cobaltous choride-induced hypothermia in mice I: effect of pretreatment with anticholinergic drugs. 66 Apr 60

Thermoregulatory behavior was assessed in the rat by measuring the time taken to escape from a radiant heat source. The time to excape and the rise in core temperature accompanying exposure to heat were greater in morphine dependent (1 X 75 mg SC pellet implant for 72 hr) than in control rats. Injection of naloxone (1 mg/kg) into dependent rats produced a withdrawal hypothermia and decreased the time taken to escape from the heat source. Since rats undergoing withdrawal avoided heat at the same time that their core temperature was falling, the hypothermia is most likely due to a downward setting of the central thermostats rather than a direct activation of heat loss pathways. Both the withdrawal hypothermia and the behavioral changes were blocked by pimozide pretreatment (0.5 mg/kg) implicating a dopaminergic mechanism in the downward setting of the thermostats. Administration of naloxone 144 hr after pellet implantation produced similar effects to those in the 72 hr implanted group. Injection of morphine sulfate (4 mg/kg) 144 hr after implantation increased both the core temperature and the time taken to escape from heat suggesting that the effect of morphine in the dependent rat is to produce an upward setting of the thermostats.
 ...
PMID:Dopaminergic involvement in withdrawal hypothermia and thermoregulatory behavior in morphine dependent rats. 94 79

Pretreatment with valine (0.5-2.0 mmoles/kg) can suppress the hypothermic response of rats placed in a 4degreesC environment and given d-amphetamine sulfate (5 or 10 mg/kg). The amino acid was most effective when given 30 minutes before amphetamine administration, at which time it also significantly lowered brain tyrosine concentration (and, presumably, suppressed catecholamine synthesis). Because dopaminergic neurons mediate the hypothermic response to amphetamine and because amphetamine's ability to produce hypothermia requires, in part, the release of newly synthesized dopamine, these observed effects of valine pretreatment support the hypothesis that treatments which alter precursor (tyrosine) availability also affect brain catecholamine synthesis.
 ...
PMID:Suppression of amphetamine-induced hypothermia by the neutral amino acid valine. 99 76

The mechanism underlying the hyperthermic response to low doses of morphine has been investigated in rats. Doses of morphine sulfate less than 10 mg/kg i.p. caused a rise in body temperature accompanied by vasoconstriction of the cutaneous blood vessels of the tail. This hyperthermia, unlike the hypothermia following higher doses of morphine was not blocked by naloxone nor did tolerance develop to the response. Injections directly into the hypothalamus suggested that, as with the fall in temperature after high doses of morphine, the hyperthermic effect is also due to an action on the preoptic/anterior hypothalamic thermoregulatory centers. Experiments measuring thermoregulatory behavior showed that rats delayed escaping from a heat load after low doses of morphine even though their core temperature was rising. These results suggest that low doses of morphine raise the set point of the central thermostats in rats resulting in a hyperthermia mediated, at least in part, by decreased cutaneous heat loss.
 ...
PMID:Morphine hyperthermia in the rat: an action on the central thermostats. 126 1

Six experiments examined the effects of low (5-10 degrees C), normal (21 degrees C), or high (32 degrees) ambient temperature on conditioned taste aversion and body temperature changes produced by ethanol, lithium chloride, or morphine sulfate. Fluid-deprived rats received five to seven taste conditioning trials at 48-hr intervals. On each trial, access to saccharin at normal ambient temperature was followed by injection of drug or saline and placement for 6 hr into a temperature-controlled enclosure. Exposure to low ambient temperature facilitated, whereas exposure to high ambient temperature retarded acquisition of ethanol-induced conditioned taste aversion. The ability of an alteration in ambient temperature to influence conditioned taste aversion varied as a function of ethanol dose and was related to ambient temperature's effect on ethanol-induced hypothermia. More specifically, strength of conditioned taste aversion was negatively correlated with core body temperature after ethanol injection. Alterations in ambient temperature alone did not affect ingestion of a paired flavor solution in the absence of drug. Moreover, alterations in ambient temperature did not appear to influence conditioned taste aversion by changing ethanol pharmacokinetics. Finally, high and low ambient temperature did not affect development of taste aversion conditioned by lithium chloride or morphine sulfate. The overall pattern of data presented by these experiments supports the hypothesis that ambient-temperature influences strength of ethanol-induced conditioned taste aversion by altering the hypothermic response to ethanol. More generally, these data support the suggestion that body temperature change induced by ethanol is related to ethanol's aversive motivational effects and may be involved in modulating ethanol intake.
 ...
PMID:Ambient temperature effects on taste aversion conditioned by ethanol: contribution of ethanol-induced hypothermia. 147 66

The authors conducted a retrospective analysis of the case records of 757 patients who underwent correction of acquired heart valvular disease under conditions of hypothermia without perfusion. Intrapleural hemorrhage occurred in the postoperative period in 43 (5.7%) patients, in 35 of them rethoracotomy had to be performed to arrest the bleeding. In patients with aortal valvular diseases a relation was revealed between the postoperative blood loss and the patient's age, the volume of operative blood loss (reverse correlation), and total dose of protamine sulfate (direct correlation), in patients with mitral valvular diseases the postoperative blood loss was related to the volume of diuresis in the first postoperative day (direct correlation). It is concluded that defective surgical hemostasis is the main cause of intrapleural hemorrhages after correction of acquired valvular diseases of the heart under conditions of hypothermia without perfusion.
 ...
PMID:[Intrapleural hemorrhages after the correction of acquired heart defects under hypothermia without perfusion]. 148 88

3-alpha-Hydroxy-5-beta-pregnan-20-one [pregnanolone (PA)] and 3-beta-hydroxy-5-pregnen-20-one 3-sulfate [pregnenolone sulfate (PS)] are steroids that have been shown in biochemical studies to be active at the GABA-benzodiazepine-chloride receptor complex, Pa as a "barbiturate-like" agonist and PS as a "picrotoxin-like" antagonist. Since other compounds that are active at this site interact with the effects of pentobarbital and ethanol, the behavioral effects of these steroids alone and in combination with pentobarbital and ethanol were tested. Pa blocks the convulsions caused by pentylenetetrazole (PTZ) and increases motor activity when given alone in low doses. In combination with either pentobarbital or ethanol, it enhances the depression in motor activity, hypothermia, and hypnosis. In contrast, PS has no effect on PTZ convulsions and depresses motor activity by itself. With pentobarbital, PS enhances the depression in motor activity but has no effect on hypothermia or hypnosis. With ethanol, PS enhances the hypothermia but does not affect motor activity or hypnosis. Therefore, Pa and PS show different but not opposite effects in interacting with compounds active at the GABA-benzodiazepine-chloride receptor complex.
 ...
PMID:Interaction of pregnanolone and pregnenolone sulfate with ethanol and pentobarbital. 151 42

Premature birth still accounts for about 75% of perinatal mortality. Although great strides have been made in the care of premature babies over the past two decades, markedly decreasing mortality, the prevention of premature birth has not been greatly improved. Although tocolysis, particularly with the beta-2 agonists and magnesium sulfate, may delay birth and allow fetal maturation, it poses several risks which, if not recognized, can cause serious morbidity and even mortality. The use of these drugs and other less widely used tocolytics has important implications for the anesthesiologist. The premature infant itself is subjected to such risks as RDS, IVH, NEC, asphyxia, hypothermia, increased incidence of breech presentation, metabolic disturbances, and predisposition for trauma. To ensure safe delivery, premature babies should be delivered in a tertiary care center equipped and ready to attend to their needs. Major conduction block, particularly continuous lumbar epidural analgesia, is an ideal form of analgesia for the delivery of most premature neonates. Properly administered, it maintains maternal physiology, is not associated with drug depression in the newborn, enables a controlled, atraumatic vaginal delivery, and has little interaction with tocolytics (and indeed may protect against some of their side effects). It is ideal for a trial of labor and, if initiated early, allows for an emergency cesarean section. Continuous lumbar epidural block and subarachnoid block are both superb for elective or urgent cesarean section. However, when their use is contraindicated, inhalation analgesia for vaginal delivery or general anesthesia for cesarean section can be safely administered from the standpoint of both mother and child. Expertly administered anesthesia is not a luxury but is indeed indispensable for successful premature delivery.
 ...
PMID:Anesthetic considerations in premature birth. 196 45

Cerebral protection by hypothermia is commonly attributed to cerebral metabolic suppression. However, at temperatures below 28 degrees C, the relationship of temperature to cerebral metabolic rate of oxygen consumption (CMRO2) has not been well characterized. Accordingly, the relationship between brain temperature and CMRO2 was determined in eight dogs during cooling from 37 to 14 degrees C while the EEG was continuously monitored. Cardiopulmonary bypass was initiated and control measurements were made at 37 degrees C during anesthesia with nitrous oxide 50-60% inspired and morphine sulfate 2 mg.kg-1 intravenously (iv). Upon cooling to 27 degrees C, the nitrous oxide was discontinued and the morphine was antagonized with naloxone 2 mg iv. Measurements were repeated at 27, 22, 18, and 14 degrees C and in four dogs again at 37 degrees C after nitrous oxide 50-60% had been reestablished at 27 degrees C along with administration of morphine sulfate 2 mg.kg-1. For each temperature interval, the temperature coefficient (Q10) for CMRO2 was calculated (Q10 = CMRO2 at x degrees C divided by CMRO2 at [x - 10] degrees C). Between 37 and 27 degrees C the Q10 was 2.23, but between 27 and 14 degrees C the mean Q10 was doubled to 4.53. With rewarming to 37 degrees C, CBF and CMRO2 returned to control levels, and brain biopsies revealed a normal brain energy state. During cooling, the EEG developed burst suppression at or below 22 degrees C. With further cooling, the periods of suppression increased; however, burst activity continued in seven of eight dogs even at 14 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:The relationship among canine brain temperature, metabolism, and function during hypothermia. 206 37

The analysis of blood loss in profound perfusion-free hypothermia has shown that its main cause is that heparin neutralization was performed only after the warming of a patient to 34-35 degrees C. The results of in vitro studies have shown that heparin was effectively neutralized by protamine sulfate at room temperature (20 degrees C). Using protamine sulfate, heparin neutralization was performed at 25-27 degrees C in 90 patients, which reduced blood loss by 10-15% of the circulating blood volume and made it possible to avoid hemotransfusions in the post-operative period.
 ...
PMID:[Early neutralization of heparin during heart surgery of acquired heart defects using perfusion-free hypothermia (28-24C)]. 207 20


1 2 3 4 5 6 7 8 Next >>