Phosphate-Activated Glutaminase-Containing Neurons in the Rat Paraventricular Nucleus Express Angiotensin Type 1 Receptors
| Autor: | Adolfo E. Cuadra, Nan Jiang, Leah N. Braseth, Shun Lu, Colin Sumners, Mohan K. Raizada, Peng Shi, Hongwei Li |
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| Rok vydání: | 2009 |
| Předmět: |
Male
medicine.medical_specialty Patch-Clamp Techniques Green Fluorescent Proteins Biology Article Losartan Receptor Angiotensin Type 1 Adenoviridae Rats Sprague-Dawley Glutaminase Internal medicine Internal Medicine medicine Animals Cells Cultured Neurons Angiotensin II receptor type 1 Glutamate receptor Rostral ventrolateral medulla Angiotensin II Rats medicine.anatomical_structure Endocrinology nervous system Hypothalamus Neuron Angiotensin II Type 1 Receptor Blockers hormones hormone substitutes and hormone antagonists Paraventricular Hypothalamic Nucleus medicine.drug |
| Zdroj: | Hypertension. 54:845-851 |
| ISSN: | 1524-4563 0194-911X |
| DOI: | 10.1161/hypertensionaha.109.134684 |
| Popis: | The centrally mediated cardiovascular regulatory actions of angiotensin II in normal and hypertensive rats include angiotensin II type 1 receptor (AT1R)–mediated actions at the paraventricular nucleus (PVN) of the hypothalamus. Because the PVN consists of multiple neuronal populations, it is important to understand which neuronal types in the PVN are influenced by angiotensin II. Here we have developed a viral vector (Adeno-associated vector 2 [AAV2]-PAG-eGFP [PAG; phosphate-activated glutaminase promoter]) to drive expression of green fluorescent protein (GFP) primarily within glutamate neurons. At 10 to 14 days after bilateral microinjection (200 nL per side; 1.2×10 12 genome copies) of AAV2-PAG-eGFP into adult Sprague-Dawley rat PVN, animals were euthanized and brains removed and used for isolation and culture of PVN neurons. Fluorescence microscopy and immunostaining using neuron and PAG-specific antibodies revealed the presence of GFP-containing glutamatergic neurons in these PVN cultures. Whole-cell patch-clamp recordings demonstrated that angiotensin II (100 nmol/L) produced a 16% decrease in delayed rectifier potassium current in ≈50% of the GFP-containing neurons, an effect that was abolished by the AT1R antagonist losartan (1 μmol/L). Consistently, 9 of 28 GFP/PAG-expressing neurons contained AT1R mRNA, as indicated by single-cell RT-PCR. Furthermore, specific GFP/PAG-positive neurons in the PVN that project to the rostral ventrolateral medulla of the brain stem express immunoreactive AT1R. In conclusion, we have demonstrated the presence of functional AT1R on PAG-positive (largely glutamate) neurons within rat PVN, certain of which project to the rostral ventrolateral medulla. |
| Databáze: | OpenAIRE |
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