Abstract
In the present study, we examined the effect of inhibition of catalase with 3-amino-triazole (3-AT) on hydrogen peroxide (H2O2)-induced enhancement of sympathetic neuro-transmission in bovine irides and on the inhibitory effect of this oxidant on norepinephrine (NE) release from human irides, in vitro. Furthermore, we investigated the effect of 3-AT on H2O2-induced attenuation of contractile responses to carbachol in the bovine isolated irides. Isolated mammalian irides were prepared for studies of [3H]NE release using the superfusion method and for contractile studies using isolated organ baths. At concentrations less than 100 μM, H2O2 had no significant effect on field-stimulated [3H]NE release from bovine or human irides. In bovine irides, 3-AT caused significant (P <0.001) leftward shifts of concentration-response curves to H2O2 (10 - 300 μM). 3-AT also increased H2O2-induced attenuation of evoked [3H]NE release from human isolated irides. Low concentrations of H2O2 (<100 μM) had no effect on carbachol contractions. However, 3-AT unmasked an inhibitory effect of low concentrations of H2O2 (3 - 100 μM) on carbachol-induced contractions. We conclude that inhibition of catalase causes both pre- and postjunctional responses of isolated mammalian irides to be more susceptible to oxidative stress induced by H2O2.
| Original language | English |
|---|---|
| Pages (from-to) | 429-438 |
| Number of pages | 10 |
| Journal | Journal of Ocular Pharmacology and Therapeutics |
| Volume | 16 |
| Issue number | 5 |
| State | Published - 2000 |
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All Science Journal Classification (ASJC) codes
- Pharmacology (medical)
- Ophthalmology
- Pharmacology, Toxicology and Pharmaceutics(all)
Cite this
Role of catalase in pre- and postjunctional responses of mammalian irides to hydrogen peroxide. / Matutte, B.; Awe, S. O.; Ameh, F. A.; Leday, A. M.; Rice, J. C.; Opere, Catherine A.; Ohia, S. E.
In: Journal of Ocular Pharmacology and Therapeutics, Vol. 16, No. 5, 2000, p. 429-438.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Role of catalase in pre- and postjunctional responses of mammalian irides to hydrogen peroxide
AU - Matutte, B.
AU - Awe, S. O.
AU - Ameh, F. A.
AU - Leday, A. M.
AU - Rice, J. C.
AU - Opere, Catherine A.
AU - Ohia, S. E.
PY - 2000
Y1 - 2000
N2 - In the present study, we examined the effect of inhibition of catalase with 3-amino-triazole (3-AT) on hydrogen peroxide (H2O2)-induced enhancement of sympathetic neuro-transmission in bovine irides and on the inhibitory effect of this oxidant on norepinephrine (NE) release from human irides, in vitro. Furthermore, we investigated the effect of 3-AT on H2O2-induced attenuation of contractile responses to carbachol in the bovine isolated irides. Isolated mammalian irides were prepared for studies of [3H]NE release using the superfusion method and for contractile studies using isolated organ baths. At concentrations less than 100 μM, H2O2 had no significant effect on field-stimulated [3H]NE release from bovine or human irides. In bovine irides, 3-AT caused significant (P <0.001) leftward shifts of concentration-response curves to H2O2 (10 - 300 μM). 3-AT also increased H2O2-induced attenuation of evoked [3H]NE release from human isolated irides. Low concentrations of H2O2 (<100 μM) had no effect on carbachol contractions. However, 3-AT unmasked an inhibitory effect of low concentrations of H2O2 (3 - 100 μM) on carbachol-induced contractions. We conclude that inhibition of catalase causes both pre- and postjunctional responses of isolated mammalian irides to be more susceptible to oxidative stress induced by H2O2.
AB - In the present study, we examined the effect of inhibition of catalase with 3-amino-triazole (3-AT) on hydrogen peroxide (H2O2)-induced enhancement of sympathetic neuro-transmission in bovine irides and on the inhibitory effect of this oxidant on norepinephrine (NE) release from human irides, in vitro. Furthermore, we investigated the effect of 3-AT on H2O2-induced attenuation of contractile responses to carbachol in the bovine isolated irides. Isolated mammalian irides were prepared for studies of [3H]NE release using the superfusion method and for contractile studies using isolated organ baths. At concentrations less than 100 μM, H2O2 had no significant effect on field-stimulated [3H]NE release from bovine or human irides. In bovine irides, 3-AT caused significant (P <0.001) leftward shifts of concentration-response curves to H2O2 (10 - 300 μM). 3-AT also increased H2O2-induced attenuation of evoked [3H]NE release from human isolated irides. Low concentrations of H2O2 (<100 μM) had no effect on carbachol contractions. However, 3-AT unmasked an inhibitory effect of low concentrations of H2O2 (3 - 100 μM) on carbachol-induced contractions. We conclude that inhibition of catalase causes both pre- and postjunctional responses of isolated mammalian irides to be more susceptible to oxidative stress induced by H2O2.
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M3 - Article
VL - 16
SP - 429
EP - 438
JO - Journal of Ocular Pharmacology and Therapeutics
JF - Journal of Ocular Pharmacology and Therapeutics
SN - 1080-7683
IS - 5
ER -