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)

Daily restraint for 3 weeks was shown to atrophy dendrites of hippocampal pyramidal neurons in rats. Brain-derived neurotrophic factor (BDNF), which maintains neuronal survival and morphology, has been shown to decrease in response to acute stress. Plasma glucocorticoid (GC) and serotonergic projections from the raphe nuclei play major roles in reducing BDNF synthesis in the hippocampus. We investigated BDNF mRNA levels there, together with plasma GC levels, GC receptors in the hippocampus/hypothalamus and 5-HT synthesizing enzyme, tryptophan hydroxylase in the raphe nuclei, in animals chronically stressed for 1-3 weeks, using in situ hybridization and immunohistochemistry. In these animals, BDNF mRNA levels were significantly decreased in the hippocampus after 6 h of restraint, but the ability of restraint to reduce BDNF synthesis seemed less robust than that seen in acute stress models. HPA axis response to stress in these animals assessed by plasma GC levels was delayed and sustained, and the GC receptor in the paraventricular hypothalamic nucleus was increased at 1 week. Tryptophan hydroxylase immunoreactivity was increased in the median raphe nucleus at 2-3 weeks. Repetitive stress-induced reduction of BDNF may partly contribute to the neuronal atrophy/death and reduction of hippocampal volume observed both in animals and humans suffering chronic stress and/or depression.
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PMID:Chronic stress, as well as acute stress, reduces BDNF mRNA expression in the rat hippocampus but less robustly. 1602 25

Chronic stress and alterations in the serotonergic system are key predisposing factors to the development of major depression. Tryptophan hydroxylase (TPH) is the key enzyme in the biosynthesis of serotonin (5-HT). The effects of chronic stress on TPH activity remain uncertain. The BALB/c strain is stress-sensitive, highly anxious and possess a single nucleotide polymorphism in their tryptophan hydroxylase (TPH) 2 gene (tph2), resulting in reduced levels of central serotonin compared to C57BL/6J mice, which harbour the wild-type allele. We examined the effects of repeated restraint stress on the serotonergic system and TPH activity in these two inbred strains. TPH activity was assessed by accumulation of 5-hydroxytryptophan, a rapidly decarboxylated intermediate metabolite of tryptophan and precursor of 5-HT, using an enzyme inhibition strategy. Furthermore, the concentrations of 5-HT and its major metabolite 5-hydroxy indole acetic acid were assessed. Interestingly, 5-HT turnover was significantly increased in the majority of the brain regions assessed following acute stress in C57BL/6J. In contrast, BALB/c mice exhibit significant increases in 5-HT turnover in the striatum and hippocampus only following repeated stress. On the other hand, TPH activity was significantly decreased in the brainstem and cortical regions of C57BL/6J mice following both acute and chronic stress. Conversely, no significant stress-induced change in BALB/c TPH activity was observed. Together these data highlight the differential serotonergic response of BALB/c and C57BL/6J mice to acute and chronic restraint stress and may offer insight into the observed differences in their stress-related phenotypes.
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PMID:Differential stress-induced alterations in tryptophan hydroxylase activity and serotonin turnover in two inbred mouse strains. 2113 Jul 84