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

Changes in catecholamines (CA) in the plasma and urine and metabolites of CA and serotonin (5-HT) in the cerebrospinal fluid of guinea-pigs in hypothermia (Trec 30 degrees C) and after subsequent rewarming were determined with HPLC in order to obtain data on early stress reactions and their timing. Both noradrenaline (NA) and adrenaline (A) were low in the plasma but high in the urine after the hypothermic period. These had normalized in the plasma after rewarming but were still high in the urine. Dopamine values tended to be low (not significant). Methoxyhydroxyphenylglycol and homovanilic acid were elevated in the cerebrospinal fluid both after hypothermia and following rewarming, and 5-hydroxyindoleacetic acid after rewarming. The ratio of adrenaline to noradrenaline, the catecholamine hypothermia index, in the urine had risen 24-fold after hypothermia and 40-fold after rewarming. The results support the view that elevated catecholamine concentrations in the urine and elevated values of their metabolites in the cerebrospinal fluid could be regarded as hypothermia markers. However, other stress conditions, which have lasted at least a few hours, should be excluded in the final interpretation.
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PMID:Plasma and urine catecholamines and cerebrospinal fluid amine metabolites as hypothermia markers in guinea-pigs. 274 75

The effects of the novel veterinary sedative, medetomidine, were studied in rats. In addition to a dose-dependent sedation, which at high doses (greater than 100 micrograms/kg) included loss of the righting reflex and hypothermia, there was a concurrent decrease in the turnover rate of biogenic amines in the brain. Noradrenaline turnover was dose dependently decreased as judged by (i) the decrease in the brain concentration of its metabolite, MHPG-SO4, (ii) a decrease in the ability of alpha-methyl-p-tyrosine methyl ester to deplete brain noradrenaline stores and (iii) a dose-dependent decrease in the level of unconjugated MHPG in the CSF of freely moving rats. Brain dopamine turnover was also inhibited at higher doses as judged by the alpha-methyl-p-tyrosine method and by a decrease in the concentration of HVA in the rat brain 4 h after medetomidine. Serotonin turnover as estimated by the ratio of biogenic amine to its metabolite was also significantly depressed. These changes in brain biogenic amine turnover were inhibited by prior or simultaneous administration of alpha 2-adrenoceptor antagonists, either yohimbine or the more specific, novel alpha 2-antagonist, atipamezole.
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PMID:Behavioural and neurochemical effects of medetomidine, a novel veterinary sedative. 290 7

This study examined the localized action of neuropeptide Y (NPY) on monoamine transmitter activity in the hypothalamus of the unrestrained rat as this peptide induced hypothermia, spontaneous feeding or both responses simultaneously. A guide tube was implanted in the anterior hypothalamic pre-optic area (AH/POA) of Sprague-Dawley rats. Then either control CSF vehicle or NPY in a dose of either 100 ng/microliter or 250 ng/microliter was perfused by push-pull cannulae in this structure in the fully sated, normothermic rat. Successive perfusions were carried out at a rate of 20 microliters/min for 6.0 min with an interval of 6.0 min elapsing between each. Samples of perfusate were assayed by HPLC for their levels of dopamine (DA), norepinephrine (NE), serotonin (5-HT) and their respective metabolites. Whereas control CSF was without effect on body temperature (Tb) or feeding, repeated perfusions of NPY over 3.0 hr caused dose-dependent eating from 4 to 39 g of food, hypothermia of 0.9 to 2.3 degrees C or both responses concurrently. As the rats consumed 11-39 g of food, the efflux of NE, MHPG, DOPAC and 5-HT was enhanced significantly, whereas during the fall in Tb the efflux of NE, DOPAC and 5-HIAA from the AH/POA increased. When the Tb of the rat declined simultaneously with eating behavior, the levels in perfusate of DOPAC and HVA increased significantly while MHPG declined. During perfusion of the AH/POA with NPY the turnover of NE declined while DA and 5-HT turnover increased during hypothermia alone or when accompanied by feeding. These results demonstrate that the sustained elevation in NPY within the AH/POA causes a selective alteration in the activity of the neurotransmitters implicated in thermoregulation, satiety and hunger. These findings suggest that both DA and NE comprise intermediary factors facilitating the action of NPY on neurons involved in thermoregulatory and ingestive processes. The local activity of NPY on hypothalamic neurons apparently shifts the functional balance of serotonergic and catecholaminergic neurons now thought to play a primary role in the control of energy metabolism and caloric intake.
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PMID:Neuropeptide Y perfused in the preoptic area of rats shifts extracellular efflux of dopamine, norepinephrine, and serotonin during hypothermia and feeding. 882 34