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Cross talk between the intrarenal dopaminergic and cyclooxygenase-2 systems
- Source :
- American Journal of Physiology-Renal Physiology. 288:F840-F845
- Publication Year :
- 2005
- Publisher :
- American Physiological Society, 2005.
-
Abstract
- In mammalian kidney, dopamine produced in the proximal tubule (PT) acts as an autocrine/paracrine natriuretic hormone that inhibits salt and fluid reabsorption in the PT. In high-salt-treated animals, PT dopamine activity increases and inhibits reabsorption, leading to increased salt and fluid delivery to the macula densa (MD) and subsequent natriuresis and diuresis. Regulated cyclooxygenase-2 (COX-2) in the MD represents another intrinsic system mediating renal salt and water homeostasis. Renal cortical COX-2 is inversely related to salt intake, and decreased extracellular NaCl stimulates COX-2 expression in cultured MD/cortical thick ascending limb cells. The current study investigated interactions between renal dopamine and cortical COX-2 systems. In rats fed a control diet, the dopamine precursor l-dihydroxyphenylalanine (l-DOPA) or the DA1 receptor agonist SKF-81297 suppressed cortical COX-2 expression. High salt suppressed cortical COX-2 expression, which was attenuated by inhibition of dopamine production with benserazide or the DA1 receptor antagonist, SCH-23390. In contrast, l-DOPA or the dopamine-metabolizing enzyme inhibitor entacapone suppressed low-salt-induced cortical COX-2 expression. Inhibition of PT reabsorption with the carbonic anhydrase inhibitor acetazolamide suppressed cortical COX-2 expression. In contrast, treatment with distally acting diuretics led to elevation of cortical COX-2. These results indicate that dopamine modulates renal cortical COX-2 expression by modifying PT reabsorption.
- Subjects :
- Male
medicine.medical_specialty
Kidney Cortex
Physiology
Dopamine
Dopamine Agents
Gene Expression Regulation, Enzymologic
Levodopa
Rats, Sprague-Dawley
chemistry.chemical_compound
Paracrine signalling
Internal medicine
medicine
Animals
Sodium Chloride, Dietary
Diuretics
Autocrine signalling
Prostaglandin G2
Kidney
biology
Reabsorption
Dopaminergic
Receptor Cross-Talk
Benzazepines
Rats
medicine.anatomical_structure
Endocrinology
chemistry
Cyclooxygenase 2
Prostaglandin-Endoperoxide Synthases
Dopamine Agonists
biology.protein
Cyclooxygenase
medicine.drug
Subjects
Details
- ISSN :
- 15221466 and 1931857X
- Volume :
- 288
- Database :
- OpenAIRE
- Journal :
- American Journal of Physiology-Renal Physiology
- Accession number :
- edsair.doi.dedup.....304f5885725d85a8fd3cbd8c9a29eef0