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Title: Contribution of Calcium Entry through Non-Voltage Operated Calcium Channels to the Contractile Response of Vascular Smooth Muscle to Agonists
Author: Blackman, Sarah Kathryn
ISNI:       0000 0001 3466 492X
Awarding Body: King's College London (University of London)
Current Institution: King's College London (University of London)
Date of Award: 2007
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Depletion of Ca2+ stores in the sarcoplasmic reticulum results in the opening of store operated cation channels (SOCCs) on the plasma membrane, allowing Ca2 + influx into the cell and refilling of the stores. The work described in this thesis set out to determine the extent to which Ca2 + entry through the store operated pathway contributes to agonist-induced contraction. in aortic smooth mUSfle. Three major techniques were used to study agonist responses in aortae from C57BL6 mice and Wistar rats. Aortic rings were mounted in organ baths to study the pharmacology of contractile responses to noradrenaline (NA), phenylephrine (PE) thapsigargin (Tg), arg-vasopressin (AVP) and potassium chloride (KCI). These whole tissue experiments were supplemented with electrophysiological and Fura-2 microfluorimetry recordings of cells isolated from the whole tissue by enzymatic digestion. Mouse aortic ring experiments revealed that contraction in response to NA is dependent on verapamil-insensitive ion channels that can be distinguished from those activated by store depletion with Tg by their sensitivity to l-lOmM GdCh or LaCL3 • The ability of low concentrations of 2-APB to enhance contraction induced by NA suggests a role for STTh11 in mediating contraction to NA in the mouse aorta. Single cell experiments designed to further investigate SOCCs in the mouse aorta confirmed the· presence of a Ca2 +-activated chloride channel but did not confirm the presence of the SOCC reported by Trepakova et al (2001) . . Rat aortic ring experiments were carried out to investigate the role of nitric oxide (NO) in the reciprocal regulation model of receptor and store operated calcium entry. No evidence was obtained for the involvement of smooth muscle NO in modulating contractions induced by phenylephrine or AVP in whole tissues.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available