Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0848237 (acute stress)
 4,619 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Turnovers of dopamine (DA), norepinephrine (NE), epinephrine (E), and 5-hydroxytryptamine (5-HT) were determined in the brains of male turkeys during acute, chronic, and posttemperature stress. Changes induced in the depletion of endogenous monoamine levels 6 h after tyrosine hydroxylase or tryptophan hydroxylase inhibitions were regarded as changes in turnovers. High or low ambient temperature had no effect on brain DA turnover, whether the temperature stress was acute (6 h) or chronic (5 wk). Brain NE turnover increased upon acute exposure to either a cold (5 degrees C) or warm (32 degrees C) environment. Chronic exposure (5 wk) to such temperatures reduced significantly (P less than 0.001) the elevated NE turnover. The central E and 5-HT turnovers of birds kept at 32 degrees C for 6 h decreased and increased, respectively, whereas determination of E and 5-HT of birds kept at 5 degrees C showed an opposite pattern. Five weeks of continuous exposure to high and low environmental temperatures did not alter the changes in E and 5-HT turnovers from those observed during acute stress. Exposure of heat- or cold-reared turkeys to 24 degrees C reversed the changes in E and 5-HT turnovers. Thus the results indicated an increase in NE turnover only during acute exposure to thermal stress. However, the changes in E and 5-HT turnovers persisted during chronic exposure.
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PMID:Brain indole and catecholamines of turkeys during exposure to temperature stress. 13 76

The effects of acute stress on norepinephrine (NE) and dopamine (DA) concentrations and of repeated stress on tyrosine hydroxylase (TH) activity were measured in individual hypothalamic nuclei and other rat brain regions. A microdissection technique and radioisotopic enzymatic assays enables these studies to be performed. NE and DA concentrations were reduced and TH activity increased selectively in the arcuate nucleus. These results suggest that the arcuate nucleus may be selectively involved in the stress response and support the hypothesis that catecholamines in the medial basal hypothalamus mediate certain of the neuroendocrine changes observed in stress.
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PMID:Effects of stress on catecholamines and tyrosine hydroxylase activity of individual hypothalamic nuclei. 24 Oct 31

The locus ceruleus-norepinephrine system is one of the principal effectors of the stress response. Acute stress induces norepinephrine synthesis and release, and noradrenergic cells compensate by increasing the activity of tyrosine hydroxylase, the rate-limiting enzyme in catecholamine synthesis. Here we use in situ hybridization histochemistry to show the effects of acute and chronic intermittent stress on the expression of tyrosine hydroxylase mRNA in the rat locus ceruleus. Restraint stress increased tyrosine hydroxylase mRNA in the locus ceruleus but not in dopaminergic nuclei such as the substantia nigra or ventral tegmental area. One hour of footshock or restraint caused a rapid increase in locus ceruleus tyrosine hydroxylase mRNA which returned to basal levels within 24 h. Chronic intermittent stress (1 hour of restraint or footshock per day for 14 days) produced no change in tyrosine hydroxylase mRNA. Neither adrenalectomy nor dexamethasone replacement significantly affected mRNA expression. These findings indicate that acute stress can increase the expression of tyrosine hydroxylase mRNA in the locus ceruleus but that adaptation occurs to repeated stress, and that the expression of tyrosine hydroxylase mRNA in the locus ceruleus is independent of direct glucocorticoid modulation.
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PMID:Effects of stress and adrenalectomy on tyrosine hydroxylase mRNA levels in the locus ceruleus by in situ hybridization. 167 1

Corticotropin-releasing factor (CRF) and norepinephrine (NE) mediate many hormonal, autonomic, and behavioral effects of acute stress, and it is possible that an interaction between these neurotransmitters could underlie neuronal adaptations in response to chronic stress. To test this hypothesis, the influence of chronically administered CRF and a specific CRF antagonist, alpha-helical CRF, on the induction of tyrosine hydroxylase, the rate-limiting enzyme in NE biosynthesis, was examined in the rat locus coeruleus (LC). We now report that administration of alpha-helical CRF specifically blocks the induction of tyrosine hydroxylase in response to a repeated intermittent stress paradigm involving foot shock and noise stress but has no effect on steady-state levels of the enzyme in nonstressed animals or on the induction of the enzyme in response to reserpine treatment. In addition, repeated administration of CRF alone for 5 days, like chronic stress, increases levels of tyrosine hydroxylase in LC. The results demonstrate that endogenous CRF is necessary for the induction of tyrosine hydroxylase in response to this stress paradigm and that exogenously administered CRF is sufficient for the regulation of this enzyme in nonstressed rats. These findings may prove important in elucidating mechanisms by which chronic stress triggers and sustains the biochemical alterations associated with some stress-related psychiatric disorders.
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PMID:Involvement of corticotropin-releasing factor in chronic stress regulation of the brain noradrenergic system. 168 36

Previous studies have demonstrated the ability of tyrosine (TYR), the amino acid precursor of catecholamines, to increase blood pressure in rats made hypotensive by haemorrhage. Other studies have shown that supplementation of the diet with TYR can reverse certain neurochemical and behavioural consequences associated with acute stress. Such studies demonstrate that during conditions of enhanced neuronal firing catecholamine synthesis is accelerated when additional precursor TYR is made available. In these situations the rate-limiting enzyme of catecholamine synthesis, tyrosine hydroxylase, activated via phosphorylation, becomes responsive to additional TYR. Our experiments were designed to study the ability of dietary TYR (3.7%, or 4X the normal amount), to prevent the rapid fall in blood pressure observed during acute haemorrhage. Rats consuming the high TYR diet (5 days) maintained arterial blood pressure (systolic, diastolic and mean) at significantly greater values during the period of acute haemorrhagic insult than animals maintained on a control diet. Rats fed the high TYR diet had significantly greater levels of the amino acid in the heart, adrenal glands, liver, kidney, brainstem, spleen and semimembranosus pars caudalis muscle. We conclude that TYR can be stored and most likely utilized in the synthesis of catecholamines for the maintenance of arterial blood pressure during acute haemorrhage. These results are of particular importance in light of the fact that most total parenteral nutrition solutions contain very little if any TYR.
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PMID:Dietary supplementation of tyrosine prevents the rapid fall in blood pressure during haemorrhage. 280 83

The effects of acute stress on serum prolactin concentrations and tuberoinfundibular dopaminergic (TIDA) neuronal activity were studied in female rats. TIDA neuronal activity was estimated by measuring the rate of dihydroxyphenylalanine (DOPA) accumulation after the administration of a decarboxylase inhibitor (NSD 1015) and the rate of decline of dopamine (DA) after the administration of a tyrosine hydroxylase inhibitor (alpha-methyltyrosine) in the median eminence. Serum prolactin concentrations were increased following 30 min of supine immobilization (restraint stress), but returned to control levels by 2, 8, and 16 h after the onset of this stress. The rate of DOPA accumulation was decreased during the 30 min of restraint; it was still further reduced 2 h later but had returned to control levels 8 and 16 h later. No change in the rate of DOPA accumulation was observed in the striatum or neurointermediate lobe of the pituitary at any time after the start of restraint. Restraint stress also decreased the rate of DA turnover in the median eminence, but was without effect on the rates of DA turnover in the striatum or neurointermediate lobe. These results suggest that restraint stress activates an inhibitory neuronal pathway which decreases the activity of TIDA neurons and may be responsible, at least in part, for the increase in serum prolactin concentrations. The responsiveness of TIDA neurons to the stress-induced decrease in activity was not influenced by the time of day or the stage of the estrous cycle. Not all stressful manipulations decreased TIDA neuronal activity.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Acute restraint stress decreases dopamine synthesis and turnover in the median eminence: a model for the study of the inhibitory neuronal influences on tuberoinfundibular dopaminergic neurons. 405 76

The administration of pargyline to normal rats enhanced the adrenal catecholamines noradrenaline + adrenaline content, tyrosine hydroxylase (TH) and catechol -0-methyl transferase (COMT) activity together with a reduction in monoamine oxidase (MAO) activity. The pargyline pretreated rats exposed to acute stress exhibited a significant increase in adrenal catecholamine content and COMT activity with no change in TH and phenylethanolamine-N-emthyl transferase (PNMT) activity as compared to normal stressed rats. However, adrenal MAO activity was decreased in pargyline pretreated stressed rats. Thus, these observations tend to suggest that pargyline treatment before exposure to stress considerably influence the usual stress response in term of catecholamine metabolism.
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PMID:Catecholamine metabolism in pargyline treated rats exposed to stress. 610 92

Effects of psychotropic drugs on emotional reactivity and behavior under acute stress were studied in rats with 6-hydroxydopamine (6-HDA)-destroyed catecholaminergic brain terminals. The differences in emotional and behavioral reactivity were found in the group of animals who received 6-HDA. An abrupt reduction of tyrosine hydroxylase activity in corpus striatum of "emotional" rats correlates with noticeable difficulties in the behavior of escape out of stress and essential differences in the effects of psychotropic drugs whose action is mediated via the catecholamine neurotransmitter system.
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PMID:[Relation between the nature of psychotropic effects on emotional reactivity and behavior in stress situations and the status of the brain's catecholaminergic systems]. 611 38

The time course of regulation of rat adrenomedullary phenylethanolamine N-methyltransferase (PNMT) and tyrosine hydroxylase (TH) activity was studied after a single episode of 20-min restraint stress. Significant increases in PNMT and TH activity were observed 18 h after the beginning of the stress. The time course of acute stress-induced regulation of PNMT and TH was examined for the influence of neural and hormonal input. Unilateral denervation was performed, and the animals were exposed to a single episode of restraint. PNMT activity increased similarly in both the innervated and denervated adrenals, with a significant increase observed at 36 h after the stress. TH activity was similar in both denervated and innervated adrenals, with a significant increase observed at 24 and 36 h after stress. Finally, suppression of endogenous corticosterone with dexamethasone delayed the stress-induced increase in activity of PNMT but not TH. The present study indicates that increases in catecholamine biosynthetic enzymes can be observed after a single episode of mild, acute stress. In addition, glucocorticoids appear to be important in the time course of the stress-induced increase in PNMT but not TH activity, whereas neural input does not seem to affect the time course of these increases.
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PMID:Regulation of the adrenomedullary catecholaminergic system after mild, acute stress. 791 70

Multiple neurochemical estimates were used to examine peripheral corticosterone (CORT) effects in dopaminergic terminal regions. Acute CORT administration, which elevated plasma CORT (5 h), slightly decreased dihydroxyphenylacetic acid (DOPAC) to dopamine (DA) ratios in the striatum but not in other regions examined. Two weeks of adrenalectomy (ADX) increased both medial prefrontal cortex DOPAC/DA and homovanillic acid (HVA)/DA and striatal HVA/DA. A reciprocal pattern of changes was observed with CORT replacement in ADX animals. In contrast, CORT replacement in ADX animals did not significantly influence tyrosine hydroxylase content, basal dihydroxyphenylalanine (DOPA) accumulation after NSD 1015 treatment or the decline in DA after alpha-methyl-para-tyrosine, suggesting that neither DA neuronal activity nor release are altered by CORT. Moreover, neither gamma-hydroxybutyric acid lactone-induced increases in DOPA accumulation or stress-induced increases in DA utilization were influenced by CORT replacement, indicating that neither autoreceptor regulation of DA synthesis nor acute stress regulation of DA utilization are changed by CORT. The findings are most consistent with direct inhibition of basal DA metabolism in the medial prefrontal cortex and striatum. The possible physiological and behavioral significance of this inhibition is being further explored.
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PMID:Glucocorticoid effects on mesotelencephalic dopamine neurotransmission. 1045 37


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