Differential expression of catecholamine biosynthetic enzymes in the rat ventrolateral medulla
| Autor: | John Chalmers, Paul M. Pilowsky, Erekle Sesiashvili, Ratna Dubey, Jacqueline K. Phillips, Janusz Lipski, Mamoru Takeda, Ann K. Goodchild |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Male
medicine.medical_specialty Tyrosine 3-Monooxygenase Immunocytochemistry Dopamine beta-Hydroxylase Biology Axonal Transport Gene Expression Regulation Enzymologic Rats Sprague-Dawley chemistry.chemical_compound Dopamine Internal medicine medicine Animals Rats Wistar Medulla Neurons Medulla Oblongata Tyrosine hydroxylase Reverse Transcriptase Polymerase Chain Reaction Phenylethanolamine N-Methyltransferase General Neuroscience Colocalization Rostral ventrolateral medulla Immunohistochemistry Rats Phenylethanolamine Endocrinology chemistry Aromatic-L-Amino-Acid Decarboxylases Catecholamine Female medicine.drug |
| Zdroj: | The Journal of Comparative Neurology. 432:20-34 |
| ISSN: | 1096-9861 0021-9967 |
| DOI: | 10.1002/cne.1086 |
| Popis: | Adrenergic (C1) neurons located in the rostral ventrolateral medulla are considered a key component in the control of arterial blood pressure. Classically, C1 cells have been identified by their immunoreactivity for the catecholamine biosynthetic enzymes tyrosine hydroxylase (TH) and/or phenylethanolamine N-methyltransferase (PNMT). However, no studies have simultaneously demonstrated the expression of aromatic L-amino acid decarboxylase (AADC) and dopamine beta-hydroxylase (DBH) in these neurons. We examined the expression and colocalization of all four enzymes in the rat ventrolateral medulla using immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) analysis. Retrograde tracer injected into thoracic spinal segments T2-T4 was used to identify bulbospinal neurons. Using fluorescence and confocal microscopy, most cells of the C1 group were shown to be double or triple labeled with TH, DBH, and PNMT, whereas only 65-78% were immunoreactive for AADC. Cells that lacked detectable immunoreactivity for AADC were located in the rostral C1 region, and approximately 50% were spinally projecting. Some cells in this area lacked DBH immunoreactivity (6.5-8.3%) but were positive for TH and/or PNMT. Small numbers of cells were immunoreactive for only one of the four enzymes. Numerous fibres that were immunoreactive for DBH but not for TH or PNMT were noted in the rostral C1 region. Single-cell RT-PCR analysis conducted on spinally projecting C1 neurons indicated that only 76.5% of cells that contained mRNA for TH, DBH, and PNMT contained detectable message for AADC. These experiments suggest that a proportion of C1 cells may not express all of the enzymes necessary for adrenaline synthesis. |
| Databáze: | OpenAIRE |
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