Abstract
Monitoring the expression of immediate early genes (IEGs) is useful for following stress-induced cellular responses in the neuroendocrine system. We have examined the transcriptional activities of four IEGs (c-fos, junB, NGFI-A and NGFI-B) and of the arginine vasopressin (AVP) gene in the hypothalamic paraventicular (PVN) and supraoptic nuclei (SON) of rats after acute osmotic stimuli, using in situ hybridization histochemistry. After intraperitoneal (i.p.) administration of hypertonic saline (2% body weight, 900 mOsm/kg), the expression levels of all IEG mRNAs were increased significantly both in the PVN and SON at as early as 10 min, peaked at 30 min and remained elevated until 60 min. The expression of AVP heteronuclear (hn)RNA also peaked at 30 min, and remained elevated until 180 min. Thirty min after i.p. administration of hypertonic saline (600 mOsm/kg), the expression levels of all IEG mRNAs in the PVN and SON were significantly increased in comparison with those after i.p. administration of isotonic saline (290 mOsm/kg). Regression analysis revealed that expression levels of the IEG mRNAs and AVP hnRNA were positively correlated with the plasma concentration of sodium, and the rates of increase of the expression levels of all IEG mRNAs were similar. The expression levels of all IEG mRNAs examined are useful markers for following the changes of the AVP gene transcription in the PVN and SON after acute osmotic stimuli in rats.
Publication types
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Comparative Study
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Arginine Vasopressin / genetics*
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Arginine Vasopressin / metabolism
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DNA-Binding Proteins / genetics
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DNA-Binding Proteins / metabolism
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Dose-Response Relationship, Drug
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Early Growth Response Protein 1
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Gene Expression Regulation
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Immediate-Early Proteins / genetics*
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Immediate-Early Proteins / metabolism
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Male
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Nuclear Receptor Subfamily 4, Group A, Member 1
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Osmotic Pressure
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Paraventricular Hypothalamic Nucleus / metabolism*
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Proto-Oncogene Proteins c-fos / genetics
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Proto-Oncogene Proteins c-fos / metabolism
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Proto-Oncogene Proteins c-jun / genetics
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Proto-Oncogene Proteins c-jun / metabolism
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RNA, Heterogeneous Nuclear / metabolism*
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RNA, Messenger / analysis
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Rats
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Rats, Wistar
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Receptors, Cytoplasmic and Nuclear / genetics
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Receptors, Cytoplasmic and Nuclear / metabolism
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Receptors, Steroid / genetics
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Receptors, Steroid / metabolism
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Saline Solution, Hypertonic / administration & dosage
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Sodium / blood
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Supraoptic Nucleus / metabolism*
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Transcription Factors / genetics
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Transcription Factors / metabolism
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Transcription, Genetic / physiology
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Water-Electrolyte Balance / genetics*
Substances
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DNA-Binding Proteins
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Early Growth Response Protein 1
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Egr1 protein, mouse
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Immediate-Early Proteins
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Nr4a1 protein, mouse
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Nr4a1 protein, rat
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Nuclear Receptor Subfamily 4, Group A, Member 1
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Proto-Oncogene Proteins c-fos
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Proto-Oncogene Proteins c-jun
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RNA, Heterogeneous Nuclear
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RNA, Messenger
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Receptors, Cytoplasmic and Nuclear
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Receptors, Steroid
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Saline Solution, Hypertonic
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Transcription Factors
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Arginine Vasopressin
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Sodium