Evidence for regulation of tyrosine hydroxylase mRNA translation by stress in rat adrenal medulla
| Autor: | Xiqun Chen, A. William Tank, Lu Xu, Carol R. Sterling, Baoyong Sun |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Male
Restraint Physical medicine.medical_specialty Time Factors Tyrosine 3-Monooxygenase Antimetabolites Dopamine beta-Hydroxylase Biology Deoxyglucose Gene Expression Regulation Enzymologic Article Rats Sprague-Dawley Polysome Internal medicine Gene expression medicine Animals Secretion RNA Messenger Molecular Biology chemistry.chemical_classification Messenger RNA Analysis of Variance Tyrosine hydroxylase Reverse Transcriptase Polymerase Chain Reaction General Neuroscience Rats Cold Temperature Endocrinology medicine.anatomical_structure Enzyme chemistry Adrenal Medulla Polyribosomes Catecholamine Neurology (clinical) Adrenal medulla Stress Psychological Developmental Biology medicine.drug |
| Zdroj: | Brain research. 1158 |
| ISSN: | 0006-8993 |
| Popis: | Long-term stress leads to the induction of tyrosine hydroxylase (TH) protein and enzymatic activity in the adrenal medulla. This adaptive response is necessary to maintain the catecholamine biosynthetic capacity of adrenal chromaffin cells during periods of sustained catecholamine secretion. In this report we demonstrate that when rats are subjected to short-term stress, TH mRNA is induced for at least 24 h, but TH protein and TH activity (assayed under Vmax conditions) are not increased. In contrast, adrenal TH mRNA, TH protein and TH activity are induced in rats subjected to long-term stress. Using sucrose gradient fractionation, we show that the lack of induction of TH protein after one type of short-term stressor, a single 2-h immobilization stress is associated with a decrease in the percentage of TH mRNA molecules associated with polysomes. In contrast, after repeated immobilizations the polysome profile of TH mRNA is identical to that observed in control animals, even though TH mRNA is induced 2- to 3-fold. These results are consistent with the hypothesis that even though TH mRNA is induced by short-term stressors, mechanisms that control TH mRNA translation must also be appropriately regulated for TH protein to be induced. |
| Databáze: | OpenAIRE |
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