Effects of Melatonin and Haloperidol Given via Vortex Vein on the Intraocular Pressure

Rohde, Brooks H.; Li, Byron H.P.; Chiou, George C.Y.

doi:10.1159/000267215

Cited by 8 publications

(5 citation statements)

References 21 publications

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“…Moreover, administration of the competitive melatonin receptor antagonist luzindole blocks the reduction of IOP mediated by melatonin agonists (Pintor et al, 2001). In contrast, increased IOP has been reported following injection of melatonin into a superior vortex vein of rabbits (Rohde et al, 1993), and intracameral infusion of melatonin in cats (Rohde et al, 1985) and rats (Chiou et al, 1985). The conflicting results of the effects of melatonin on IOP may be due to differences in species and strains, as well as methods of administration and measurement (Osborne, 1994; Pintor et al, 2001).…”

Section: Discussionmentioning

confidence: 99%

Melatonin receptor agonist-induced reduction of SNP-released nitric oxide and cGMP production in isolated human non-pigmented ciliary epithelial cells

Dortch-Carnes

Tosini

2013

Experimental Eye Research

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The present study was designed to determine the effects of melatonin and its receptor agonists on SNP-released nitric oxide (NO) and cGMP production in aqueous humor producing cells of the ciliary body because these effects may play a role in melatonin receptor-mediated regulation of intraocular pressure (IOP). NO release protocols were carried out using human non-pigmented ciliary epithelial (hNPCE) cells treated in dye free DMEM containing L-arginine (10−3 M). The cGMP experimental protocols were performed using dye free DMEM containing 3-isobutyl-1-methylxanthine (IBMX, 10−4 M). The effects of varying concentrations (10−13, 10−11, 10−9, 10−7, and 10−5 M) of melatonin, 5-MCA-NAT (putative MT3 agonist), N-butanoyl-2-(2-methoxy-6H-isoindolo[2, 1-a]indol-11-yl)ethanamine (IIK7; selective MT2 agonist) or S-27633-1 (selective MT1 agonist) on sodium nitroprusside (SNP)-released NO or cGMP production were determined in separate experiments. NO and cGMP levels were measured using a colorimetric assay or enzyme immunoassay (EIA), respectively. Melatonin receptor selectivity was evaluated using luzindole (LUZ; nonselective MT1/MT2 antagonist) or 4-phenyl-2-propionamidotetralin (4P-PDOT; selective MT2 antagonist). Melatonin, 5-MCA-NAT, and IIK7 all caused concentration-dependent reduction of SNP-released NO and cGMP production. The inhibitory actions of melatonin, 5-MCA-NAT and IIK7 were either completely blocked at 10−13, 10−11, and 10−9 M concentrations of the agonists or partially at 10−7 and 10−5 M in the presence of luzindole or 4P-PDOT. Results from this study suggest that melatonin and its analogues, 5-MCA-NAT and IIK7 inhibit SNP-released NO and cGMP production via activation of MT2 receptors in human NPCE cells. These actions may play a role in melatonin agonist-induced regulation of aqueous humor secretion and IOP.

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Section: Discussionmentioning

confidence: 99%

Melatonin receptor agonist-induced reduction of SNP-released nitric oxide and cGMP production in isolated human non-pigmented ciliary epithelial cells

Dortch-Carnes

Tosini

2013

Experimental Eye Research

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“…Melatonin levels increase during the dark in the retinae of several vertebrate species (Cahill and Besharse, 1993;Faillace et al, 1994) and melatonin itself is synthesized by photoreceptors in the amphibian retina (Cahill and Besharse, 1993). By virtue of indirectly regulating melatonin levels, CPE may be an important component in the regulation of the vertebrate circadian clock (Cahill and Besharse, 1993) and/or intraocular pressure (Rohde et al, 1993a). To date, however, there have been no reports of neuropeptide expression in photoreceptors.…”

Section: Discussionmentioning

confidence: 99%

“…In most cases, these neuropeptides likely act as neurotransmitters. Opiates such as enkephalin, however, have been proposed to have other roles in the retina including modulating neuronal growth during development (Isayama et al, 1991) and regulating intraocular pressure (Rohde et al, 1993a). Most neuropeptides are derived from the proteolytic processing of larger polypeptides.…”

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confidence: 99%

Light and dark cause a shift in the spatial expression of a neuropeptide-processing enzyme in the rat retina

Schlamp

Nickells

1996

J. Neurosci.

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Carboxypeptidase E (CPE, EC 3.4.17.10) is an essential enzyme in the post-translational processing of most neuroactive peptides. We have studied how the expression of CPE in the rat retina is modified in response to the light/dark cycle. Retinal CPE mRNA levels increase immediately after a change in lighting condition. After prolonged exposure to the dark or the light, however, CPE mRNA levels drop to comparable amounts. The increase CPE mRNA is most dramatic during the dark-to-light transition. Interestingly, during the same interval, CPE protein levels transiently decrease. This apparently contradictory change in mRNA and protein levels is attributable to a change in the spatial pattern of CPE expression in the retina in response to light and dark. Both in situ hybridization and indirect immunofluorescence studies indicate that CPE is expressed in photoreceptors in the dark. During light onset, CPE expression is rapidly induced in retinal ganglion cells, whereas expression in photoreceptors is reduced. This pattern is reversed when the animals are exposed to the dark. In contrast, CPE is apparently constitutively expressed in a subpopulation of cells in the inner nuclear layer in both the light and the dark. These changes in CPE expression are similar to light-induced changes in c-fos expression, suggesting that CPE may be a downstream target for Fos activation.

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“…53 Increases the cell viability of ARPE-19 cells 114 and lowers IOP and melatonin in iris ciliary body. 115 SNC-80 Agonist Neural differentiation, 63 antidepressant, 33 and decreases astrogliosis. 55 Increases inositol phosphate production.…”

Section: Dors: Mechanisms Of Actionmentioning

confidence: 99%

Delta Opioids: Neuroprotective Roles in Preclinical Studies

Husain

2018

Journal of Ocular Pharmacology and Therapeutics

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Since ancient times, opioids have been used clinically and abused recreationally. In the early stages (about 1,000 AD) of opium history, an Arab physician, Avicenna, administered opioids to control diarrhea and eye diseases. Opioids have very strong pain relieving properties and they also regulate numerous cellular responses. Opioid receptors are expressed throughout the body, including the nervous system, heart, lungs, liver, gastrointestinal tract, and retina. Delta opioid receptors (DORs) are a very attractive target from the perspective of both receptor function and their therapeutic potential. Due to a rapid progress in mouse mutagenesis and development of small molecules as DOR agonist, novel functions and roles of DORs have emerged in recent years. This review article focuses on the recent advances in the neuroprotective roles of DOR agonists in general and retina neuroprotection in particular. Rather than being exhaustive, this review highlights the selected studies of DOR function in neuroprotection. We also highlight our preclinical studies using rodent models to demonstrate the potentials of DOR agonists for retinal neuroprotection. Based on existing literature and our recently published data on the eye, DOR agonists possess therapeutic abilities that protect the retina and optic nerve injury against glaucoma and perhaps other retinopathies as well. This review also highlights the signaling events associated with DOR for neuroprotection in the eye. There is a need for translational research on DORs to recognize their potential for clinical application such as in glaucoma.

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Effects of Melatonin and Haloperidol Given via Vortex Vein on the Intraocular Pressure

Cited by 8 publications

References 21 publications

Melatonin receptor agonist-induced reduction of SNP-released nitric oxide and cGMP production in isolated human non-pigmented ciliary epithelial cells

Melatonin receptor agonist-induced reduction of SNP-released nitric oxide and cGMP production in isolated human non-pigmented ciliary epithelial cells

Light and dark cause a shift in the spatial expression of a neuropeptide-processing enzyme in the rat retina

Delta Opioids: Neuroprotective Roles in Preclinical Studies

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