{"id":{"repo_id":"texas-state","oai_identifier":"oai:digital.library.txst.edu:10877/19762"},"canonical_url":"https://search.dev.ndltd.org/etd/texas-state/oai:digital.library.txst.edu:10877/19762","repository":{"repo_id":"texas-state","name":"Texas State University","base_url":"https://digital.library.txst.edu/server/oai/request"},"display":{"title":"The Angiotensin Receptor (AT₁) Inhibitor, Losartan, Slows Post-Natal Thickening of the Left Ventricle","abstract":"The overall aim of this study was to test the hypothesis that a local renin angiotensin system (RAS) in the mammalian left ventricle regulates growth of heart tissue in response to pressure-overload. Upon parturition, the mammalian left ventricle (LV) experiences pressure overload to which it responds by rapid growth, becoming thicker than the right ventricle (RV) in a few days. We assessed a role for a cardiac RAS in left ventricular development by giving losartan, an angiotensin IT (AII) AT; receptor antagonist to pregnant rats. Hearts were removed from neonates, fixed and cryosections cut with litter-mates being similarly processed at 24 hour intervals. Micrographs were obtained and morphometric analyses were performed to compare wall thickness in the left and night ventricles during neonatal development. No significant difference was found between the hearts of losartan-treated neonates and non-treated neonates. Losartan, however, inhibited LV wall thickening in treated rats during the first 48 hours of development. These results implicate involvement of the LV AT, receptor. Immunohistochemical detection of angiotensinogen (AQ) in a parallel study of these hearts indicated increased levels in the LV during the first 24 post-natal hours. These results support a role for the cardiac RAS system in controlling LV wall thickness in mammalian heart.","abstract_html":"The overall aim of this study was to test the hypothesis that a local renin angiotensin system (RAS) in the mammalian left ventricle regulates growth of heart tissue in response to pressure-overload. Upon parturition, the mammalian left ventricle (LV) experiences pressure overload to which it responds by rapid growth, becoming thicker than the right ventricle (RV) in a few days. We assessed a role for a cardiac RAS in left ventricular development by giving losartan, an angiotensin IT (AII) AT; receptor antagonist to pregnant rats. Hearts were removed from neonates, fixed and cryosections cut with litter-mates being similarly processed at 24 hour intervals. Micrographs were obtained and morphometric analyses were performed to compare wall thickness in the left and night ventricles during neonatal development. No significant difference was found between the hearts of losartan-treated neonates and non-treated neonates. Losartan, however, inhibited LV wall thickening in treated rats during the first 48 hours of development. These results implicate involvement of the LV AT, receptor. Immunohistochemical detection of angiotensinogen (AQ) in a parallel study of these hearts indicated increased levels in the LV during the first 24 post-natal hours. These results support a role for the cardiac RAS system in controlling LV wall thickness in mammalian heart.","abstract_has_math":false,"creators":["Javadi, Fariba"],"institution":"Southwest Texas State University","degree_name":"Master of Science","degree_level":"Masters","degree_discipline":"Biology","degree_department":null,"school":null,"contributors":[],"advisors":["Koke, Joseph R."],"committee_chairs":[],"committee_members":["Garcia, Dana M.","Rose, Francis L."],"year":1994,"date_issued":"1994-12","date_published":"1994-12","updated_at":"2026-07-27T21:22:45Z","subjects":["angiotensin","heart","left ventricle","rats"],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/10877/19762","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Koke, Joseph R."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Garcia, Dana M.","Rose, Francis L."]},{"key":"dc:creator","label":"Author","values":["Javadi, Fariba"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2024-11-13T22:27:00Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2024-11-13T22:27:00Z"]},{"key":"dc:date.issued","label":"Date","values":["1994-12"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Southwest Texas State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["angiotensin","heart","left ventricle","rats"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/10877/19762"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The overall aim of this study was to test the hypothesis that a local renin angiotensin system (RAS) in the mammalian left ventricle regulates growth of heart tissue in response to pressure-overload. Upon parturition, the mammalian left ventricle (LV) experiences pressure overload to which it responds by rapid growth, becoming thicker than the right ventricle (RV) in a few days. We assessed a role for a cardiac RAS in left ventricular development by giving losartan, an angiotensin IT (AII) AT; receptor antagonist to pregnant rats. Hearts were removed from neonates, fixed and cryosections cut with litter-mates being similarly processed at 24 hour intervals. Micrographs were obtained and morphometric analyses were performed to compare wall thickness in the left and night ventricles during neonatal development. No significant difference was found between the hearts of losartan-treated neonates and non-treated neonates. Losartan, however, inhibited LV wall thickening in treated rats during the first 48 hours of development. These results implicate involvement of the LV AT, receptor. Immunohistochemical detection of angiotensinogen (AQ) in a parallel study of these hearts indicated increased levels in the LV during the first 24 post-natal hours. These results support a role for the cardiac RAS system in controlling LV wall thickness in mammalian heart."]},{"key":"dc:format","label":"Dc Format","values":["Text"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["1 file (.pdf)"]},{"key":"dc:title","label":"Title","values":["The Angiotensin Receptor (AT₁) Inhibitor, Losartan, Slows Post-Natal Thickening of the Left Ventricle"]}]}],"canonical_facts":{"dc:contributor.advisor":["Koke, Joseph R."],"dc:contributor.committeemember":["Garcia, Dana M.","Rose, Francis L."],"dc:creator":["Javadi, Fariba"],"dc:date.accessioned":["2024-11-13T22:27:00Z"],"dc:date.available":["2024-11-13T22:27:00Z"],"dc:date.issued":["1994-12"],"dc:description.abstract":["The overall aim of this study was to test the hypothesis that a local renin angiotensin system (RAS) in the mammalian left ventricle regulates growth of heart tissue in response to pressure-overload. 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Immunohistochemical detection of angiotensinogen (AQ) in a parallel study of these hearts indicated increased levels in the LV during the first 24 post-natal hours. These results support a role for the cardiac RAS system in controlling LV wall thickness in mammalian heart."],"dc:format":["Text"],"dc:format.medium":["1 file (.pdf)"],"dc:identifier.uri":["https://hdl.handle.net/10877/19762"],"dc:language.iso":["en"],"dc:subject":["angiotensin","heart","left ventricle","rats"],"dc:title":["The Angiotensin Receptor (AT₁) Inhibitor, Losartan, Slows Post-Natal Thickening of the Left Ventricle"],"dc:type":["Thesis"],"thesis:degree_discipline":["Biology"],"thesis:degree_level":["Masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Southwest Texas State University"]},"updated_at":"2026-07-27T21:22:45Z"}