Title:
Mechanical and metabolic stresses contribute to high force contraction signaling

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dc.contributor.advisor Burkholder, Thomas
dc.contributor.author Rahnert, Jill Anne en_US
dc.contributor.committeeMember Balog, Edward
dc.contributor.committeeMember Gleason, Rudolph
dc.contributor.committeeMember Sokoloff, Alan
dc.contributor.committeeMember Warren, Gordon
dc.contributor.corporatename School of Applied Physiology
dc.contributor.corporatename School of Biological Sciences
dc.contributor.corporatename College of Sciences
dc.contributor.corporatename College of Sciences
dc.contributor.corporatename School of Biological Sciences
dc.contributor.department Applied Physiology en_US
dc.date.accessioned 2012-06-06T16:43:02Z
dc.date.available 2012-06-06T16:43:02Z
dc.date.issued 2012-03-27 en_US
dc.description.abstract Force production by a muscle is critical to maintaining proper function and overall health of a human or animal. Muscle adapts to increased loading with hypertrophy by activating a number of intracellular signaling cascades that regulate protein synthesis. The overall hypothesis is that force-dependent processes acutely activate growth-related signaling during active force generation. This project took two approaches. The first employed a general survey of muscles in which age-dependent changes in muscle activity differed. No conclusive activity-dependent signaling emerged however coordinated signaling among kinases broke down with age. The second approach utilized an in situ muscle preparation in which force production or metabolic costs were specifically controlled. Similar sub-maximal force levels generated by different methods found that force, per se, is not a primary modulator of growth-related signaling but that ERK phosphorylation is dependent on fiber-activation. Prolonging the duration of electrical stimulation applied to the nerve or increasing the frequency at which stimulations are applied was expected to increase the metabolic stress associated with contraction. Several growth-related kinases correlated with markers of metabolic stress, i.e. increased AMPK activity and decreased glycogen content, which were decoupled from force decline. This suggests energy depletion, specific to stimulation pattern, strongly influences the immediate response to high force contraction signaling. The overall conclusion is that signaling molecules previously implicated in force-dependent signaling lie much too downstream to relay strict force-dependent signaling. en_US
dc.description.degree PhD en_US
dc.identifier.uri http://hdl.handle.net/1853/43636
dc.publisher Georgia Institute of Technology en_US
dc.subject Mechanotransduction en_US
dc.subject Muscle en_US
dc.subject Force en_US
dc.subject MAP kinase en_US
dc.subject P70S6 kinase en_US
dc.subject Signaling en_US
dc.subject Tongue en_US
dc.subject Metabolic stress en_US
dc.subject.lcsh Cells Growth
dc.subject.lcsh Muscles
dc.subject.lcsh Muscles Regeneration
dc.title Mechanical and metabolic stresses contribute to high force contraction signaling en_US
dc.type Text
dc.type.genre Dissertation
dspace.entity.type Publication
local.contributor.corporatename College of Sciences
local.contributor.corporatename School of Biological Sciences
local.relation.ispartofseries Doctor of Philosophy with a Major in Applied Physiology
relation.isOrgUnitOfPublication 85042be6-2d68-4e07-b384-e1f908fae48a
relation.isOrgUnitOfPublication c8b3bd08-9989-40d3-afe3-e0ad8d5c72b5
relation.isOrgUnitOfPublication 85042be6-2d68-4e07-b384-e1f908fae48a
relation.isSeriesOfPublication ead85f7a-56bd-4216-a2d8-a66530e2e8b9
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