Abstract
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 F(2α) (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's on NE release may be mediated by Tx-receptors.
| Original language | English |
|---|---|
| Pages (from-to) | 491-496 |
| Number of pages | 6 |
| Journal | Neurochemical Research |
| Volume | 25 |
| Issue number | 4 |
| DOIs | |
| State | Published - 2000 |
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All Science Journal Classification (ASJC) codes
- Neuroscience(all)
- Biochemistry
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Effect of isoprostanes on sympathetic neurotransmission in the human isolated iris-ciliary body. / Awe, S. Olubusayo; Opere, Catherine A.; Harris, Lydia C.; Uketui, Afam J.; Ohia, Sunny E.
In: Neurochemical Research, Vol. 25, No. 4, 2000, p. 491-496.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effect of isoprostanes on sympathetic neurotransmission in the human isolated iris-ciliary body
AU - Awe, S. Olubusayo
AU - Opere, Catherine A.
AU - Harris, Lydia C.
AU - Uketui, Afam J.
AU - Ohia, Sunny E.
PY - 2000
Y1 - 2000
N2 - 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 F(2α) (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's on NE release may be mediated by Tx-receptors.
AB - 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 F(2α) (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's on NE release may be mediated by Tx-receptors.
UR - http://www.scopus.com/inward/record.url?scp=0034027770&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0034027770&partnerID=8YFLogxK
U2 - 10.1023/A:1007560025570
DO - 10.1023/A:1007560025570
M3 - Article
C2 - 10823581
AN - SCOPUS:0034027770
VL - 25
SP - 491
EP - 496
JO - Neurochemical Research
JF - Neurochemical Research
SN - 0364-3190
IS - 4
ER -