{"id":{"repo_id":"brock","oai_identifier":"oai:brocku.scholaris.ca:10464/3894"},"canonical_url":"https://search.dev.ndltd.org/etd/brock/oai:brocku.scholaris.ca:10464/3894","repository":{"repo_id":"brock","name":"Brock University","base_url":"https://brocku.scholaris.ca/server/oai/request"},"display":{"title":"Protein Turnover in Rat Skeletal Muscle During In Vitro Hypo-Osmotic Stress","abstract":"Hypo-osmolality influences tissue metabolism, but research on protein turnover in skeletal muscle is limited. The purpose of this investigation was to examine the effects of hypo-osmotic stress on protein turnover in rat skeletal muscle. We hypothesized increased protein synthesis and reduced degradation following hypo-osmotic exposure. EDL muscles (n=8/group) were incubated in iso-osmotic (290 Osm/kg) or hypo-osmotic (190 Osm/kg) modified medium 199 (95% O2, 5% CO2, pH 7.4, 30±2 °C) for 60 min, followed by 75 min incubations with L-U[14C]phenylalanine or cycloheximide to determine protein synthesis and degradation. Immunoblotting was performed to assess signalling pathways involved. Phenylalanine uptake and incorporation were increased by 199% and 169% respectively in HYPO from ISO (p < 0.05). This was supported by elevated phosphorylation of mTOR Ser2448 (+12.5%) and increased Thr389 phosphorylation on p70s6 kinase (+23.6%) (p < 0.05). Hypo-osmotic stress increased protein synthesis and potentially amino acid uptake. Future studies should examine the upstream mechanisms involved.","abstract_html":"Hypo-osmolality influences tissue metabolism, but research on protein turnover in skeletal muscle is limited. The purpose of this investigation was to examine the effects of hypo-osmotic stress on protein turnover in rat skeletal muscle. We hypothesized increased protein synthesis and reduced degradation following hypo-osmotic exposure. EDL muscles (n=8/group) were incubated in iso-osmotic (290 Osm/kg) or hypo-osmotic (190 Osm/kg) modified medium 199 (95% O2, 5% CO2, pH 7.4, 30±2 °C) for 60 min, followed by 75 min incubations with L-U[14C]phenylalanine or cycloheximide to determine protein synthesis and degradation. Immunoblotting was performed to assess signalling pathways involved. Phenylalanine uptake and incorporation were increased by 199% and 169% respectively in HYPO from ISO (p < 0.05). This was supported by elevated phosphorylation of mTOR Ser2448 (+12.5%) and increased Thr389 phosphorylation on p70s6 kinase (+23.6%) (p < 0.05). Hypo-osmotic stress increased protein synthesis and potentially amino acid uptake. Future studies should examine the upstream mechanisms involved.","abstract_has_math":false,"creators":["Darling, Ryan"],"institution":"Brock University","degree_name":"M.Sc. Applied Health Sciences","degree_level":"Masters","degree_discipline":"Faculty of Applied Health Sciences","degree_department":"Applied Health Sciences Program","school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2012,"date_issued":"2012-01-16","date_published":"2012-01-16","updated_at":"2026-07-24T01:23:00Z","subjects":["cell swelling","protein turnover","skeletal muscle","metabolism","hydration"],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/10464/3894","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.department","label":"Department","values":["Applied Health Sciences Program"]},{"key":"dc:creator","label":"Author","values":["Darling, Ryan"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2012-01-16T13:53:30Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2012-01-16T13:53:30Z"]},{"key":"dc:date.issued","label":"Date","values":["2012-01-16"]},{"key":"dc:type","label":"Dc Type","values":["Electronic Thesis or Dissertation"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Faculty of Applied Health Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.Sc. 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We hypothesized increased protein synthesis and reduced degradation following hypo-osmotic exposure. EDL muscles (n=8/group) were incubated in iso-osmotic (290 Osm/kg) or hypo-osmotic (190 Osm/kg) modified medium 199 (95% O2, 5% CO2, pH 7.4, 30±2 °C) for 60 min, followed by 75 min incubations with L-U[14C]phenylalanine or cycloheximide to determine protein synthesis and degradation. Immunoblotting was performed to assess signalling pathways involved. Phenylalanine uptake and incorporation were increased by 199% and 169% respectively in HYPO from ISO (p < 0.05). This was supported by elevated phosphorylation of mTOR Ser2448 (+12.5%) and increased Thr389 phosphorylation on p70s6 kinase (+23.6%) (p < 0.05). Hypo-osmotic stress increased protein synthesis and potentially amino acid uptake. Future studies should examine the upstream mechanisms involved."]},{"key":"dc:title","label":"Title","values":["Protein Turnover in Rat Skeletal Muscle During In Vitro Hypo-Osmotic Stress"]}]}],"canonical_facts":{"dc:contributor.department":["Applied Health Sciences Program"],"dc:creator":["Darling, Ryan"],"dc:date.accessioned":["2012-01-16T13:53:30Z"],"dc:date.available":["2012-01-16T13:53:30Z"],"dc:date.issued":["2012-01-16"],"dc:description.abstract":["Hypo-osmolality influences tissue metabolism, but research on protein turnover in skeletal muscle is limited. The purpose of this investigation was to examine the effects of hypo-osmotic stress on protein turnover in rat skeletal muscle. We hypothesized increased protein synthesis and reduced degradation following hypo-osmotic exposure. EDL muscles (n=8/group) were incubated in iso-osmotic (290 Osm/kg) or hypo-osmotic (190 Osm/kg) modified medium 199 (95% O2, 5% CO2, pH 7.4, 30±2 °C) for 60 min, followed by 75 min incubations with L-U[14C]phenylalanine or cycloheximide to determine protein synthesis and degradation. Immunoblotting was performed to assess signalling pathways involved. Phenylalanine uptake and incorporation were increased by 199% and 169% respectively in HYPO from ISO (p < 0.05). This was supported by elevated phosphorylation of mTOR Ser2448 (+12.5%) and increased Thr389 phosphorylation on p70s6 kinase (+23.6%) (p < 0.05). Hypo-osmotic stress increased protein synthesis and potentially amino acid uptake. Future studies should examine the upstream mechanisms involved."],"dc:identifier.uri":["http://hdl.handle.net/10464/3894"],"dc:language.iso":["eng"],"dc:subject":["cell swelling","protein turnover","skeletal muscle","metabolism","hydration"],"dc:title":["Protein Turnover in Rat Skeletal Muscle During In Vitro Hypo-Osmotic Stress"],"dc:type":["Electronic Thesis or Dissertation"],"thesis:degree_discipline":["Faculty of Applied Health Sciences"],"thesis:degree_level":["Masters"],"thesis:degree_name":["M.Sc. Applied Health Sciences"],"thesis:institution_name":["Brock University"]},"updated_at":"2026-07-24T01:23:00Z"}