Clonidine and PGE2 have different effects on Na+ and water transport in rat and rabbit CCD
| Autor: | Lu Chen, M.C. Reif, James A. Schafer |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
medicine.medical_specialty
Vasopressin Physiology Sodium Prostaglandin chemistry.chemical_element In Vitro Techniques Clonidine Dinoprostone Permeability chemistry.chemical_compound Internal medicine medicine Animals Adrenergic agonist Prostaglandin E2 Kidney Tubules Collecting Desoxycorticosterone Water transport urogenital system Water Biological Transport Rats Electrophysiology Endocrinology chemistry Permeability (electromagnetism) Rabbits medicine.drug |
| Zdroj: | The American journal of physiology. 261(1 Pt 2) |
| ISSN: | 0002-9513 |
| Popis: | We examined the effects of prostaglandin E2 (PGE2) and the adrenergic agonist clonidine on osmotic water permeability (Pf), lumen-to-bath 22Na+ flux (Jl----b), and transepithelial voltage (VT) in isolated perfused cortical collecting ducts (CCD) from rats and rabbits. Although PGE2 inhibited arginine vasopressin (AVP)-dependent Jl----b and Pf in CCDs from deoxycorticosterone (DOC)-treated and untreated rabbits, 0.1-10 microM PGE2 had no inhibitory effect on any of these transport parameters in CCDs from DOC-treated rats in presence of AVP. On the other hand, clonidine (1 microM in bathing solution) reversibly inhibited AVP-dependent Pf, Jl----b, and VT in the rat CCD by 30-40%, and 0.3 microM yohimbine, a specific alpha 2-adrenoceptor antagonist, reversed these effects. However, we were unable to demonstrate any inhibitory effect of 1-10 microM clonidine on Pf, Jl----b, or VT in the rabbit CCD using a variety of protocols. These results are consistent with the pattern of inhibition of AVP-dependent adenosine 3',5'-cyclic monophosphate (cAMP) production in the rat and rabbit CCD in that PGE2 inhibits both transport and cAMP production in the rabbit but not the rat CCD, and clonidine inhibits both transport and cAMP production in the rat but not the rabbit CCD [D. Chabardes, C. Brick-Ghannam, M. Montegut, and S. Siaume-Perez, Am. J. Physiol. 255 (Renal Fluid Electrolyte Physiol. 24): F43–;F48, 1988]. |
| Databáze: | OpenAIRE |
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