The cyclic AMP-activated sodium current in the molluscan neuron: A kinetic analysis of regulation by diffusion, phosphodiesterase and calcium ion

Effects of cyclic AMP on pedal neurons of the marine mollusc, Pleurobranchaea californica were studied by intracellular iontophoresis of cyclic AMP under voltage clamp condition. The I$\sb{\rm Na,cAMP}$ response to cyclic AMP injection is resistant to protein kinase inhibitors, and is very likely mediated by direct cyclic AMP binding to the channel receptor. The slow I$\sb{\rm Na,cAMP}$ is regulated by diffusion-hydrolysis kinetics: it varied in latency to current onset, latency to peak amplitude, and amplitude with the distance of the membrane to the tip of the iontophoretic cyclic AMP injection electrode; the phosphodiesterase inhibitor isobutylmethyxanthine (IBMX) in increasing concentrations motonically decreased the decay rates of the I$\sb{\rm Na,cAMP}$ response. A diffusion-reaction model incorporating terms for diffusion and degradation of cyclic AMP accurately fitted the time course of I$\sb{\rm Na,cAMP}$ response to a pulse of cyclic AMP. An application of the model allows extraction of phosphodiesterase activity as a first-order rate constant from the exponential decay phase of the I$\sb{\rm Na,cAMP}$ response.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physiology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Huang, Rong-Chi

• Biology, Neuroscience
• Biology, Animal Physiology

Statement dc:rights

• Copyright 1989 Huang, Rong-Chi

Language dc:language

eng

Identifier

AAI9010897
(UMI)AAI9010897

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/21576