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 physiological effects and certain aspects of cardiac metabolism were studied in 14 patients undergoing primary aortic valve replacement. The operations were performed under moderate hypothermia (30 degrees +/- 2 degrees C) and blood for coronary perfusion was taken from a sidebranch of the arterial line. The majority of the hearts went spontaneously into ventricular fibrillation at some stage of the operation. In spite of the high resistance measured in the coronary perfusion cannulae, an intraluminar coronary blood flow of 380 ml/min was recorded. The myocardial oxygen uptake decreased to 6.0 ml/min at 29 degrees C compared with 20.0 ml/min at 36 degrees C. The elevated coronary sinus lactate throughout the period of coronary perfusion and the increasing level of ASAT-enzyme indicated that this technique could not fully protect the myocardium from ischaemic changes. One patient died of myocardial infarction and two others needed vasopressor support postoperatively, in spite of documented effective coronary perfusion throughout the procedure. Cannulation of the coronary sinus is a valuable adjunct for the study of cardiac metabolism during ECC and it was accomplished without complications.
 ...
PMID:Myocardial protection during aortic valve replacement. Physiological and metabolic effects of selective coronary perfusion on the fibrillating heart. 3 82

The effect of acute oxygen deficiency on the rat brain peptide-hydrolases (EC 3.4) activity was studied under conditions of acute hypoxic hypoxia (the pressure in altitude chamber 240 mm Hg) with concomitant hypothermia (--5.8 degree C) and without it. The activity of neutral peptide hydrolases decreases by 29% in rats with hypothermia, in animals with normothermia remains unchanged. The activity of acid peptide hydrolases was the control level. The data obtained are compared with those relative to preservation of the content of soluble proteins under hypoxia with hypothermia.
 ...
PMID:[Effects of oxygen deficiency on rat brain peptide-hydrolase activity with and without hypothermia]. 3 20

Intraperitoneal administration of a peripheral decarboxylase inhibitor benserazide (Ro4-4602) to unanesthetized rats produced alterations in body temperature which depended on ambient temperature. In the cold, hypothermia was brought about by a decrease in metabolic heat production. At room temperature, a dose-dependent hypothermia was preceded by a slight hyperthermia. The hypothermia was due to an increase in skin temperature (tail) and a decrease in metabolic heat production, while the hyperthermia was due to a decrease in skin temperatures (both tail and footsole) and an increase in metabolic heat production. In the heat, hyperthermia responses to benserazide were associated with decrease in skin temperature (both tail and footsole). Benserazide treatment produced no significant change in brain 5-HT content. Chlorpromazine-induced hypothermia was greatly enhanced after pretreatment of the animals with benserazide at room temperature (22 degrees).
 ...
PMID:The effects of a decarboxylase inhibitor, benserazide, on both thermoregulation and chlorpromazine-induced hypothermia in rats. 3 39

Two hundred fifty patients more than 2 years of age having correction of congenital heart diseases by simple deep hypothermia alone were investigated in respect to metabolic abnormalities, post-operative complications, intellectual development and postoperative EEGs. LOS in lethal complications was attributed to the difficulty of resuscitation, indicating the application of this method is ideal for patients less than 6 years in age or less than 20 kg in weight. No impairment of intellectual development was observed when compared IQ before the operation and at the time of long term follow-up in serial study, but electroencephalographic assessment indicated that postoperative abnormalities might occur more frequently than previously suspected. Conclusively, it would appear that hypothermic intracardiac surgery is a safe method, provided circulatory arrest time is not allowed to exceed a limited period and the procedure is reasonably performed having a good understanding in the pathophysiology of hypothermia.
 ...
PMID:Simple deep hypothermia for open-heart surgery. 3 48

The semisynthetic ergot derivative lisuride induced dose- and time-dependent hypothermia in rats placed in a cold environment (+4 degrees C). As regards dosage, lisuride was more than 100 times more effective in this test model than bromocriptine. The effect of both drugs could be reduced by pretreatment with the dopamine antagonist haloperidol, which indicated a dopaminergic action of both drugs. In contrast, the hypothermic effect of lisuride could not be impaired by pretreatment with sulpiride, whilst the effects of bromocriptine were clearly antagonized by this drug. This results could be explained by a different affinity of these drugs to the same receptors, or, more likely, by a different mechanism of action by which lisuride and bromocriptine activate dopaminergic systems.
 ...
PMID:Hypothermic action of lisuride in rats and differences to bromocriptine in the antagonistic effect of neuroleptics. 3 72

A single intraperitoneal (i.p.) injection in mice of apomorphine (I) and its analogues norapomorphine (II), N-ethylnorapomorphine (III), N-n-propylnorapomorphine (IV) and apocodeine (V), caused dose-related decreases in deep-core body temperature. The neuroleptic agent haloperidol blocked the hypothermia produced by these apomorphines but alpha-methyl-p-tyrosine failed to do so. This indicated a direct post-synaptic stimulation of dopamine receptors. Methysergide potentiated the hypothermic effect of the apomorphine analogues. Taking the amount of apomorphine to produce a 3 degree C fall in temperature at 30 min as unity, the approximate relative potencies were: I 1.00, II 0.06, III 47.50, IV 85.00, V 0.340. The doses of the apomorphines needed to produce hypothermia were much less than those needed to cause stereotypy. The ratios of the minimal doses required to produce hypothermia, to those producing stereotypy were: I 8.82, II 4.00, III 125.00, IV 28.50, V 1.43.
 ...
PMID:Hypothermic effects of apomorphine homologues in mice. 3 2

Body temperature depression was noted in rats, mice, and hamsters following intraperitoneal cobaltous chloride administration (25 mg/kg). Intracerebral cobalt injection elicited hypotermia in rats and mice but not in hamsters. Body temperature depression appeared to be centrally mediated in rats and mice and peripherally mediated in hamsters. The effect of intraperitoneal and intracerebral pretreatment with phentolamine, diphenhydramine, propranolol, cimetidine, and naloxone on the mouse rectal temperature response to cobalt (25 mg/kg ip) was noted. Systemic phentolamine injection (intraperitoneal) did not alter the cobalt response, whereas intracerebral administration partially antagonized cobalt-induced hypothermia, indicating that antagonism was mediated centrally. Pretreatment with propranolol and cimetidine failed to modify the temperature response. Intracerebral diphenhydramine did not influence cobalt hypothermia. However, this agent reduced the cobalt response when given intraperitoneally, presumably through a peripheral inhibitory mechanism. The intracerebral injection of naloxone 30 min prior to cobalt slightly enhanced hypothermia, apparently through a central action. Intracerebral 6-hydroxydopamine injection depleted brain norepinephrine and dopamine but exhibited no apparent influence on cobalt-induced hypothermia.
 ...
PMID:Cobaltous chloride-induced hypothermia. II: Pretreatment with sympathoplegics, antihistamines, and narcotic antagonists. 3 17

Deep hypothermic circulatory arrest facilitates repair of congenital cardiac anomalies in infants. It is known empirically that hypothermia protects against central nervous system (CNS) ischemic damage. The Q10O2 is only 2.2 for brain and thus a decrease in metabolic rate does not fully account for protective effects of hypothermia. Since enthalpy of dissociation of H2O is high (approximately 7 kcal/mole), its pH is temperature dependent (7.0 at 25 degrees C, 7.4 at 20 degrees C) and hypothermia may in part protect by its influence on hydrogen ion concentration. A manifestation of CNS susceptibility to ischemia is an obstruction of the microcirculation [no-reflow lesion (NRL)] demonstrated by infusion of carbon black into the cerebral circulation after a period of circulatory arrest. White lesions (NRL) against a gray background on cut section of brain increase in size with increasing time of arrest. The effect of anoxia versus circulatory arrest, brain temperature, and extracellular brain pH on NRL was studied in 45 mongrel dogs, subjected to varying periods of N2-induced anoxia on cardiopulmonary bypass (CPB) at 37 degrees C or 20 degrees C. In some studies jugular venous pH was adjusted by infusion of NaHCO3 or HCl. Control groups included normothermic CPB without anoxic and normothermic CPB, anoxia, and equimolar NaCl infusion. NRL was quantified by planimetry of photographs of cut sections of brain. These results confirm that NRL is abated by hypothermia and suggest that (1) NRL is a function of anoxia and not arrested circulation since perfusion with N2 at 37 degrees C does not protect the brain (i.e., NRL is not solely related to "critical reopening pressure") and (2) NRL is in part a function of extracellular pH.
 ...
PMID:Cerebral anoxia: effect of deep hypothermia and pH. 3 7

The tranquillising activity of 3-[gamma-(p-fluorobenzoyl)propyl]-2,3,4,4a,5,6-hexahydro-1-(H)-pyrazino [1, 2-a]quinoline hydrochloride (centpyraquin), a new adrenergic neurone blocking antihypertensive agent, has been evaluated in various laboratory animals. The compound has a calming effect in mice, rats, cats and monkeys. In low doses it reduces the spontaneous motor activity followed in progressively higher doses by hypothermia, ptosis and catalepsy and a taming effect in monkeys and cats. It potentiates pentobarbitone-, hexobarbitone- and ethanol-induced sleep and antagonises amphetamine induced toxicity in mice. It, however, fails to antagonise morphine induced mania and hyperactivity in cats. It blocks conditioned avoidance response in rats at a much lower dose (ED50 = 2.73 mg/kg) than the unconditioned response (ED50 = 10,9 mg/kg). In cats centpyraquin increases the voltage and slows the frequency of cortical EEG discharges. Centpyraquin has the profile of activity of a neuroleptic on the central nervous system.
 ...
PMID:Pharmacological studies on 3-[gamma-(p-fluorobenzoyl)propyl]-2,3,4,4a,5,6-hexahydro-1-(H)-pyrazino ]1,2-a] quinoline hydrochloride (compound 69/183). Part III: Assessment of tranquillising activity. 3 55

Taurine (10 and 20 micrograms) injected unilaterally into the lateral ventricle of rats caused an increase in core temperature. Bilateral injection of taurine 2.5 and 5 micrograms into the preoptic region of the anterior hypothalamus induced a dose-related hyperthermia: higher doses (10 micrograms) caused hypothermia. Intrahypothalamically taurine-induced hyperthermia was blocked by prior injection of strychnine hydrochloride (5 and 15 micrograms); doses which alone had no effect on core temperature. Of the other inhibitory amino acids injected intrahypothalamically hypotaurine also induced a hyperthermia. GABA (10 micrograms) caused hypothermia; glycine (10 micrograms) had no effect. Potassium (50 mM) stimulated release of radioactivity from superfused slices of anterior hypothalamus prelabelled with [3H]taurine in a calcium-dependent manner. A high affinity uptake mechanism with a Km of 8.5 microM was demonstrated with [3H]taurine into slices of anterior hypothalamus. Taurine may have a neurotransmitter role in the anterior hypothalamus but whether the body temperature effects represent physiological or pharmacological events remains to be established.
 ...
PMID:Role of taurine as a possible transmitter in the thermoregulatory pathways of the rat. 3 17


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>