{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/26566"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/26566","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Glycogen extraction from skeletal muscle sarcoplasmic reticulum: structural and functional implications","abstract":"In this investigation, skeletal muscle sarcoplasmic reticulum (SR) was purified from female Sprague Dawley rats (200-250 g). SR samples were subjected to two different biochemical glycogen-extraction protocols. The results suggest that both amylase and removal of EDTA (No-EDTA) from the homogenization and storage buffers reduced the amount of glycogen associated with the SR. Both of these treatments failed to impair SR calcium (Ca2+) handling when assayed under conditions where exogenous ATP was added and utilized for SR Ca2+ transport. In fact, these treatments seemed to cause a small increase in both SR Ca2+-uptake and release rates under these assay conditions. As expected, glycogen phosphorylase content was reduced as a result of glycogen extraction in the presence of amylase, however this was not the case for No-EDTA samples. Interestingly, many other proteins differed in content after glycogen extraction. These treatments resulted in a greater recovery of the sarco(endo)plasmic reticulum Ca2+ adenosine triphosphatase (SERCA) and a substantial loss of glycogen phosphorylase and glycogen debranching enzyme (AGL) in amylase-treated samples. Creatine kinase (CK) and pyruvate kinase (PK) contents were increased as a result of both glycogen-extraction conditions. It was imperative to consider these altered protein contents while analyzing the data and assessing the effects of glycogen extraction on SR Ca2+ handling. After normalizing to SERCA content, only No-EDTA samples had higher adenosine triphosphate (ATP)-supported SR Ca2+-uptake rates compared to control samples. For endogenously synthesized ATP-supported SR Ca2+-uptake experiments, normalizing data to protein content (either CK and SERCA or PK and SERCA) revealed that amylase-treated samples had lower SR Ca2+-uptake rates, compared to control samples. Although not significant, SR Ca2+-uptake rates for No-EDTA samples were also lower than control samples. These data suggest that changes in endogenously supported SR Ca2+-uptake due to glycogen extraction affected the source of ATP synthesis (either PK or CK), the effectiveness of energy utilization for Ca2+ transport (SERCA), or altered the metabolic channeling properties.","abstract_html":"In this investigation, skeletal muscle sarcoplasmic reticulum (SR) was purified from female Sprague Dawley rats (200-250 g). SR samples were subjected to two different biochemical glycogen-extraction protocols. The results suggest that both amylase and removal of EDTA (No-EDTA) from the homogenization and storage buffers reduced the amount of glycogen associated with the SR. Both of these treatments failed to impair SR calcium (Ca2+) handling when assayed under conditions where exogenous ATP was added and utilized for SR Ca2+ transport. In fact, these treatments seemed to cause a small increase in both SR Ca2+-uptake and release rates under these assay conditions. As expected, glycogen phosphorylase content was reduced as a result of glycogen extraction in the presence of amylase, however this was not the case for No-EDTA samples. Interestingly, many other proteins differed in content after glycogen extraction. These treatments resulted in a greater recovery of the sarco(endo)plasmic reticulum Ca2+ adenosine triphosphatase (SERCA) and a substantial loss of glycogen phosphorylase and glycogen debranching enzyme (AGL) in amylase-treated samples. Creatine kinase (CK) and pyruvate kinase (PK) contents were increased as a result of both glycogen-extraction conditions. It was imperative to consider these altered protein contents while analyzing the data and assessing the effects of glycogen extraction on SR Ca2+ handling. After normalizing to SERCA content, only No-EDTA samples had higher adenosine triphosphate (ATP)-supported SR Ca2+-uptake rates compared to control samples. For endogenously synthesized ATP-supported SR Ca2+-uptake experiments, normalizing data to protein content (either CK and SERCA or PK and SERCA) revealed that amylase-treated samples had lower SR Ca2+-uptake rates, compared to control samples. Although not significant, SR Ca2+-uptake rates for No-EDTA samples were also lower than control samples. These data suggest that changes in endogenously supported SR Ca2+-uptake due to glycogen extraction affected the source of ATP synthesis (either PK or CK), the effectiveness of energy utilization for Ca2+ transport (SERCA), or altered the metabolic channeling properties.","abstract_has_math":false,"creators":["Lees, Simon J."],"institution":"Virginia Tech","degree_name":"Ph. D.","degree_level":"doctoral","degree_discipline":"Human Nutrition, Foods, and Exercise","degree_department":"Human Nutrition, Foods, and Exercise","school":null,"contributors":[],"advisors":[],"committee_chairs":["Williams, Jay H."],"committee_members":["Ward, Christopher W.","Newton, William E.","Barbeau, William E.","Moore, David M."],"year":2003,"date_issued":"2003-03-27","date_published":"2003-03-27","updated_at":"2026-07-22T22:18:41Z","subjects":["skeletal muscle","glycogen","sarcoplasmic reticulum","calcium handling"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-03312003-141236"],"render_values":[{"text":"etd-03312003-141236","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/26566","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Williams, Jay H."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Ward, Christopher W.","Newton, William E.","Barbeau, William E.","Moore, David M."]},{"key":"dc:contributor.department","label":"Department","values":["Human Nutrition, Foods, and Exercise"]},{"key":"dc:creator","label":"Author","values":["Lees, Simon J."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T20:08:39Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T20:08:39Z","2007-04-04"]},{"key":"dc:date.issued","label":"Date","values":["2003-03-27"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Human Nutrition, Foods, and Exercise"]},{"key":"thesis:degree_level","label":"Degree Level","values":["doctoral"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph. 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SR samples were subjected to two different biochemical glycogen-extraction protocols. The results suggest that both amylase and removal of EDTA (No-EDTA) from the homogenization and storage buffers reduced the amount of glycogen associated with the SR. Both of these treatments failed to impair SR calcium (Ca2+) handling when assayed under conditions where exogenous ATP was added and utilized for SR Ca2+ transport. In fact, these treatments seemed to cause a small increase in both SR Ca2+-uptake and release rates under these assay conditions. As expected, glycogen phosphorylase content was reduced as a result of glycogen extraction in the presence of amylase, however this was not the case for No-EDTA samples. Interestingly, many other proteins differed in content after glycogen extraction. These treatments resulted in a greater recovery of the sarco(endo)plasmic reticulum Ca2+ adenosine triphosphatase (SERCA) and a substantial loss of glycogen phosphorylase and glycogen debranching enzyme (AGL) in amylase-treated samples. Creatine kinase (CK) and pyruvate kinase (PK) contents were increased as a result of both glycogen-extraction conditions. It was imperative to consider these altered protein contents while analyzing the data and assessing the effects of glycogen extraction on SR Ca2+ handling. After normalizing to SERCA content, only No-EDTA samples had higher adenosine triphosphate (ATP)-supported SR Ca2+-uptake rates compared to control samples. For endogenously synthesized ATP-supported SR Ca2+-uptake experiments, normalizing data to protein content (either CK and SERCA or PK and SERCA) revealed that amylase-treated samples had lower SR Ca2+-uptake rates, compared to control samples. Although not significant, SR Ca2+-uptake rates for No-EDTA samples were also lower than control samples. These data suggest that changes in endogenously supported SR Ca2+-uptake due to glycogen extraction affected the source of ATP synthesis (either PK or CK), the effectiveness of energy utilization for Ca2+ transport (SERCA), or altered the metabolic channeling properties."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Ph. D."]},{"key":"dc:title","label":"Title","values":["Glycogen extraction from skeletal muscle sarcoplasmic reticulum: structural and functional implications"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Williams, Jay H."],"dc:contributor.committeemember":["Ward, Christopher W.","Newton, William E.","Barbeau, William E.","Moore, David M."],"dc:contributor.department":["Human Nutrition, Foods, and Exercise"],"dc:creator":["Lees, Simon J."],"dc:date.accessioned":["2014-03-14T20:08:39Z"],"dc:date.available":["2014-03-14T20:08:39Z","2007-04-04"],"dc:date.issued":["2003-03-27"],"dc:description.abstract":["In this investigation, skeletal muscle sarcoplasmic reticulum (SR) was purified from female Sprague Dawley rats (200-250 g). SR samples were subjected to two different biochemical glycogen-extraction protocols. The results suggest that both amylase and removal of EDTA (No-EDTA) from the homogenization and storage buffers reduced the amount of glycogen associated with the SR. Both of these treatments failed to impair SR calcium (Ca2+) handling when assayed under conditions where exogenous ATP was added and utilized for SR Ca2+ transport. In fact, these treatments seemed to cause a small increase in both SR Ca2+-uptake and release rates under these assay conditions. As expected, glycogen phosphorylase content was reduced as a result of glycogen extraction in the presence of amylase, however this was not the case for No-EDTA samples. Interestingly, many other proteins differed in content after glycogen extraction. These treatments resulted in a greater recovery of the sarco(endo)plasmic reticulum Ca2+ adenosine triphosphatase (SERCA) and a substantial loss of glycogen phosphorylase and glycogen debranching enzyme (AGL) in amylase-treated samples. Creatine kinase (CK) and pyruvate kinase (PK) contents were increased as a result of both glycogen-extraction conditions. It was imperative to consider these altered protein contents while analyzing the data and assessing the effects of glycogen extraction on SR Ca2+ handling. After normalizing to SERCA content, only No-EDTA samples had higher adenosine triphosphate (ATP)-supported SR Ca2+-uptake rates compared to control samples. For endogenously synthesized ATP-supported SR Ca2+-uptake experiments, normalizing data to protein content (either CK and SERCA or PK and SERCA) revealed that amylase-treated samples had lower SR Ca2+-uptake rates, compared to control samples. Although not significant, SR Ca2+-uptake rates for No-EDTA samples were also lower than control samples. These data suggest that changes in endogenously supported SR Ca2+-uptake due to glycogen extraction affected the source of ATP synthesis (either PK or CK), the effectiveness of energy utilization for Ca2+ transport (SERCA), or altered the metabolic channeling properties."],"dc:description.degree":["Ph. D."],"dc:identifier.other":["etd-03312003-141236"],"dc:identifier.uri":["http://hdl.handle.net/10919/26566"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["skeletal muscle","glycogen","sarcoplasmic reticulum","calcium handling"],"dc:title":["Glycogen extraction from skeletal muscle sarcoplasmic reticulum: structural and functional implications"],"dc:type":["Dissertation"],"thesis:degree_discipline":["Human Nutrition, Foods, and Exercise"],"thesis:degree_level":["doctoral"],"thesis:degree_name":["Ph. D."],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:18:41Z"}