Characterization of the Serotonin Receptors in the Long Posterior Ciliary Artery of the Bovine Eye

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dc.contributor.advisorQuist, Eugene
dc.contributor.committeeMemberMartin, Michael
dc.contributor.committeeMemberPang, Iok-Hou
dc.creatorLandry, Theresa A.
dc.date.accessioned2019-08-22T19:30:12Z
dc.date.available2019-08-22T19:30:12Z
dc.date.issued2000-08-01
dc.date.submitted2013-10-10T06:30:13-07:00
dc.description.abstractLandry, Theresa A., Characterization of the Serotonin Receptors in the Long Posterior Ciliary Artery of the Bovine Eye. Doctor of Philosophy (Biomedical Science), August 2000, 14 pp., 5 tables, 29 illustrations, bibliography, 104 titles. Vascular disease and vasospasm are implicated in the etiology of glaucoma. The long posterior ciliary (LPCA) is the major blood supply for the ciliary body including the ciliary processes that produce aqueous humor. Information about the pharmacological control of this vessel would be helpful in understanding its normal and pathologic function. Serotonin (5-HT) is a neurotransmitter that effectively constricts the LPCA. The objective of this research is to identify the serotonin receptor subtype responsible for the 5-HT induced vasoconstriction of the LPCA and to characterize the cellular mechanisms that mediate that contraction. Ring segments of the LPCA were dissected from bovine eyes and mounted on tungsten triangles attached to a force transducer. Changes in vascular tension were measured and recorded using a physiography recorder. Dose response curves with 5-HT, 5-HT 1-like agonist, 5-CT, and 5-HT2 agonist, α-methyl-5-HT, indicate that the 5-HT 1-like receptor contributed about 15.13% to the contraction and the 5-HT2 receptor contributed to 61.61%. The EC50 for the three agonists were 283 nM (5-HT), 336 nM (5-CT), and 1.7 μM (α-methyl-5-HT). Inhibition curves with selective antagonists indicate that the IC50 is (5-HT 1-like antagonist) and ketanserin (5-HT2 antagonist). Following incubation of the rings with diltiazem 10 μM or nifedipine 10μM, the response to 5-HT was reduced 65.*% and 61.7% respectively. Incubation in calcium free PB produced similar results. Ryanodine inhibited the 5-HT contraction by 58.1% and caffeine inhibited the response 100%. PKC inhibitors bisindolymaleimide II 1 μM, disindolylamalemide II 10 μM, chelerythrine 25 μM and H-7 5 μM decreased the 5-HT response by19.8%, 55.7%, 31.1% and 61.5% respectively. Incubation of the ring segments with one of three PLC antagonists, 2-NCDC 70 μM, U73122 0.5μM, or neomycin 5 mM, prior to the addition of 1 μM serotonin, significantly reduced the contraction of each vessel, p [less than] 0.0001. The 5-HT-induced vasoconstriction of the LPCA of the bovine eye is mediated through activation of both 5-HT2 and 5-HT 1-like receptors. The contraction is dependent on the mobilization of calcium and is mediated in part through PLC activated intracellular calcium release from IP3 sensitive stores.
dc.format.mimetypeapplication/pdf
dc.identifier.urihttps://hdl.handle.net/20.500.12503/25936
dc.language.isoen
dc.provenance.legacyDownloads0
dc.subjectBehavioral Neurobiology
dc.subjectBiomechanics
dc.subjectCell and Developmental Biology
dc.subjectCell Biology
dc.subjectCirculatory and Respiratory Physiology
dc.subjectComparative and Laboratory Animal Medicine
dc.subjectDevelopmental Biology
dc.subjectEye Diseases
dc.subjectLife Sciences
dc.subjectMedicine and Health Sciences
dc.subjectMolecular and Cellular Neuroscience
dc.subjectNeuroscience and Neurobiology
dc.subjectOphthalmology
dc.subjectOptometry
dc.subjectOther Physiology
dc.subjectPhysiology
dc.subjectSense Organs
dc.subjectVision Science
dc.subjectCharacterization
dc.subjectserotonin receptors
dc.subjectbovine eye
dc.subjectlong posterior ciliary artery
dc.subjectLPCA
dc.subjectvasoconstriction
dc.subjectblood supply
dc.subjectintracellular response
dc.subjectcalcium release
dc.subjectneurotransmitter
dc.titleCharacterization of the Serotonin Receptors in the Long Posterior Ciliary Artery of the Bovine Eye
dc.typeDissertation
dc.type.materialtext
thesis.degree.departmentGraduate School of Biomedical Sciences
thesis.degree.disciplineBiomedical Sciences
thesis.degree.grantorUniversity of North Texas Health Science Center at Fort Worth
thesis.degree.nameDoctor of Philosophy

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