{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/23309"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/23309","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Activation of smooth muscle and theories of contraction","abstract":"We have analyzed the behavior of a linear, cyclic, four state model of regulation of contraction of smooth muscle. The model involves twenty one parameters: sixteen rate constants, three initial conditions, and NT$\\sb3$ and NT$\\sb4$, where N is the number of crossbridges, and T$\\sb3$ and T$\\sb4$ are the tension of phosphorylated and dephosphorylated crossbridges, respectively. The mathematical solution, for any state, is made of the sum of three weighted exponentials plus a constant term. The parameters can be obtained if transients of phosphorylation and tension are obtained, at two different concentrations of ATP, at least, with known ADP and Pi. If only data at one concentration of ATP is available, the model can be identified as a function of ten parameters: eight effective rate constants, and NT$\\sb3$ and NT$\\sb4$. We tested the model in four sets of published experimental data, by identifying the effective rate constants plus NT$\\sb3$ and NT$\\sb4$. The model was found to fit the data well, and the values of the parameters were apparently consistent with smooth muscle physiology, or plausible explanations could be postulated for their values. The ATP turnover energetic predictions of the model were off the experimental values by a factor of fifty, in one set where this test could be done. We conclude that, although the model fits the data well, because of its energetic failure, it must be considered with strong reservations as a possible good representation of real smooth muscle. A possible reason for the failure of the model is that it is too simple. Considerations of the disparity in the number of crossbridges vs. myosin light chain kinase molecules, suggests that models that recognize this disparity would involve a large number of states. These models could have a higher ATP turnover than four state models, but at a cost of requiring much increased mathematical complexity for their quantitative analysis.","abstract_html":"We have analyzed the behavior of a linear, cyclic, four state model of regulation of contraction of smooth muscle. The model involves twenty one parameters: sixteen rate constants, three initial conditions, and NT$\\sb3$ and NT$\\sb4$, where N is the number of crossbridges, and T$\\sb3$ and T$\\sb4$ are the tension of phosphorylated and dephosphorylated crossbridges, respectively. The mathematical solution, for any state, is made of the sum of three weighted exponentials plus a constant term. The parameters can be obtained if transients of phosphorylation and tension are obtained, at two different concentrations of ATP, at least, with known ADP and Pi. If only data at one concentration of ATP is available, the model can be identified as a function of ten parameters: eight effective rate constants, and NT$\\sb3$ and NT$\\sb4$. We tested the model in four sets of published experimental data, by identifying the effective rate constants plus NT$\\sb3$ and NT$\\sb4$. The model was found to fit the data well, and the values of the parameters were apparently consistent with smooth muscle physiology, or plausible explanations could be postulated for their values. The ATP turnover energetic predictions of the model were off the experimental values by a factor of fifty, in one set where this test could be done. We conclude that, although the model fits the data well, because of its energetic failure, it must be considered with strong reservations as a possible good representation of real smooth muscle. A possible reason for the failure of the model is that it is too simple. Considerations of the disparity in the number of crossbridges vs. myosin light chain kinase molecules, suggests that models that recognize this disparity would involve a large number of states. These models could have a higher ATP turnover than four state models, but at a cost of requiring much increased mathematical complexity for their quantitative analysis.","abstract_has_math":true,"creators":["Lazalde, Carlos Armando"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Biophysics","degree_department":null,"school":null,"contributors":["Barr, L."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T14:09:34Z","date_published":"2011-05-07T14:09:34Z","updated_at":"2026-07-22T22:25:21Z","subjects":["Biology, Animal Physiology","Chemistry, Biochemistry","Biophysics, General"],"languages":["eng"],"rights":["Copyright 1992 Lazalde, Carlos Armando"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9236513","(UMI)AAI9236513"],"render_values":[{"text":"AAI9236513","href":null,"code":true},{"text":"(UMI)AAI9236513","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/23309","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Barr, L."]},{"key":"dc:creator","label":"Author","values":["Lazalde, Carlos Armando"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T14:09:34Z","10000-01-01","1992"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biophysics"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Biology, Animal Physiology","Chemistry, Biochemistry","Biophysics, General"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 1992 Lazalde, Carlos Armando"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9236513","(UMI)AAI9236513","http://hdl.handle.net/2142/23309"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["We have analyzed the behavior of a linear, cyclic, four state model of regulation of contraction of smooth muscle. The model involves twenty one parameters: sixteen rate constants, three initial conditions, and NT$\\sb3$ and NT$\\sb4$, where N is the number of crossbridges, and T$\\sb3$ and T$\\sb4$ are the tension of phosphorylated and dephosphorylated crossbridges, respectively. The mathematical solution, for any state, is made of the sum of three weighted exponentials plus a constant term. The parameters can be obtained if transients of phosphorylation and tension are obtained, at two different concentrations of ATP, at least, with known ADP and Pi. If only data at one concentration of ATP is available, the model can be identified as a function of ten parameters: eight effective rate constants, and NT$\\sb3$ and NT$\\sb4$. We tested the model in four sets of published experimental data, by identifying the effective rate constants plus NT$\\sb3$ and NT$\\sb4$. The model was found to fit the data well, and the values of the parameters were apparently consistent with smooth muscle physiology, or plausible explanations could be postulated for their values. The ATP turnover energetic predictions of the model were off the experimental values by a factor of fifty, in one set where this test could be done. We conclude that, although the model fits the data well, because of its energetic failure, it must be considered with strong reservations as a possible good representation of real smooth muscle. A possible reason for the failure of the model is that it is too simple. Considerations of the disparity in the number of crossbridges vs. myosin light chain kinase molecules, suggests that models that recognize this disparity would involve a large number of states. These models could have a higher ATP turnover than four state models, but at a cost of requiring much increased mathematical complexity for their quantitative analysis.","Made available in DSpace on 2011-05-07T14:09:34Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9236513.pdf: 5135461 bytes, checksum: 334d4c8b5b9fa6379d9ebc4e4bfab3fb (MD5) Previous issue date: 1992","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T15:03:36Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:30:19-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"]},{"key":"dc:title","label":"Title","values":["Activation of smooth muscle and theories of contraction"]}]}],"canonical_facts":{"dc:contributor":["Barr, L."],"dc:creator":["Lazalde, Carlos Armando"],"dc:date":["2011-05-07T14:09:34Z","10000-01-01","1992"],"dc:description":["We have analyzed the behavior of a linear, cyclic, four state model of regulation of contraction of smooth muscle. The model involves twenty one parameters: sixteen rate constants, three initial conditions, and NT$\\sb3$ and NT$\\sb4$, where N is the number of crossbridges, and T$\\sb3$ and T$\\sb4$ are the tension of phosphorylated and dephosphorylated crossbridges, respectively. The mathematical solution, for any state, is made of the sum of three weighted exponentials plus a constant term. The parameters can be obtained if transients of phosphorylation and tension are obtained, at two different concentrations of ATP, at least, with known ADP and Pi. If only data at one concentration of ATP is available, the model can be identified as a function of ten parameters: eight effective rate constants, and NT$\\sb3$ and NT$\\sb4$. We tested the model in four sets of published experimental data, by identifying the effective rate constants plus NT$\\sb3$ and NT$\\sb4$. The model was found to fit the data well, and the values of the parameters were apparently consistent with smooth muscle physiology, or plausible explanations could be postulated for their values. The ATP turnover energetic predictions of the model were off the experimental values by a factor of fifty, in one set where this test could be done. We conclude that, although the model fits the data well, because of its energetic failure, it must be considered with strong reservations as a possible good representation of real smooth muscle. A possible reason for the failure of the model is that it is too simple. Considerations of the disparity in the number of crossbridges vs. myosin light chain kinase molecules, suggests that models that recognize this disparity would involve a large number of states. These models could have a higher ATP turnover than four state models, but at a cost of requiring much increased mathematical complexity for their quantitative analysis.","Made available in DSpace on 2011-05-07T14:09:34Z (GMT). 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