Effect of isoprostanes on sympathetic neurotransmission in the human isolated iris-ciliary body

S. Olubusayo Awe; Catherine A. Opere; Lydia C. Harris; Afam J. Uketui; Sunny E. Ohia

doi:10.1023/A:1007560025570

Effect of isoprostanes on sympathetic neurotransmission in the human isolated iris-ciliary body

S. Olubusayo Awe, Catherine A. Opere, Lydia C. Harris, Afam J. Uketui, Sunny E. Ohia

Department of Pharmacy Sciences

Research output: Contribution to journal › Article › peer-review

19 Scopus citations

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 (US)
Pages (from-to)	491-496
Number of pages	6
Journal	Neurochemical Research
Volume	25
Issue number	4
DOIs	https://doi.org/10.1023/A:1007560025570
State	Published - 2000

All Science Journal Classification (ASJC) codes

Biochemistry
Cellular and Molecular Neuroscience

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@article{b948a57b871e4847a87c8dd1b611512f,

title = "Effect of isoprostanes on sympathetic neurotransmission in the human isolated iris-ciliary body",

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.",

author = "Awe, {S. Olubusayo} and Opere, {Catherine A.} and Harris, {Lydia C.} and Uketui, {Afam J.} and Ohia, {Sunny E.}",

note = "Funding Information: The authors thank the Nebraska Lions Eye Bank for their generous donation of human eyeballs. We are also grateful to Ms. Carol Peters and Ms. Kathy Widman for their secretarial assistance. This study was supported by National Institutes of Health grant # EY12157 to SEO.",

year = "2000",

doi = "10.1023/A:1007560025570",

language = "English (US)",

volume = "25",

pages = "491--496",

journal = "Neurochemical Research",

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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.

N1 - Funding Information: The authors thank the Nebraska Lions Eye Bank for their generous donation of human eyeballs. We are also grateful to Ms. Carol Peters and Ms. Kathy Widman for their secretarial assistance. This study was supported by National Institutes of Health grant # EY12157 to SEO.

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.

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VL - 25

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JO - Neurochemical Research

JF - Neurochemical Research

SN - 0364-3190

IS - 4

ER -

Effect of isoprostanes on sympathetic neurotransmission in the human isolated iris-ciliary body

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