| Autor: | Afam J. Uketui, Catherine A. Opere, Lydia C. Harris, Sunny E. Ohia, S. Olubusayo Awe |
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| Rok vydání: | 2000 |
| Předmět: |
Agonist
medicine.medical_specialty Thromboxane medicine.drug_class Prostaglandin General Medicine Neurotransmission Biology Biochemistry Isoprostanes Cellular and Molecular Neuroscience Norepinephrine chemistry.chemical_compound Endocrinology Eicosanoid chemistry Internal medicine medicine Arachidonic acid medicine.drug |
| Zdroj: | Neurochemical Research. 25:491-496 |
| ISSN: | 0364-3190 |
| DOI: | 10.1023/a:1007560025570 |
| Popis: | Isoprostanes (IsoP's) are prostaglandin-like compounds that are derived from free-radical catalyzed peroxidation of arachidonic acid independent of the cyclcooxygenase enzyme. In the present study, we investigated the effect of IsoP's on norepinephrine (NE) release from human isolated iris-ciliary bodies. Isolated human iris-ciliary bodies were prepared for studies of [3H]NE release using the superfusion method. Both 8-iso-prostaglandin F2α (F2-IsoP) and the thromboxane (Tx) receptor agonist, U46619 enhanced field-stimulated [3H]NE release from isolated, superfused human iris-ciliary bodies without affecting basal tritium efflux. On the other hand, an equimolar concentration (10 μM) of 8-iso-prostaglandin E2 (E2-IsoP) inhibited evoked [3H]NE overflow. The Tx-receptor antagonist, SQ 29548 blocked the enhancements of electrically-evoked [3H]NE release induced by F2-IsoP and U46619. However, the inhibitory responses elicited by E2-IsoP was not antagonized by SQ 29548. We conclude that IsoP's can produce both excitatory and inhibitory effects on sympathetic neurotransmission in human isolated iris-ciliary bodies. The stimulatory effects of IsoP' on NE release may be mediated by Tx-receptors. |
| Databáze: | OpenAIRE |
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