Effects of different durations of pretreatment with losartan on myocardial infarct size, endothelial function, and vascular endothelial growth factor
A previous study by our group showed that 10 weeks of pretreatment with losartan reduced myocardial infarct size and arrhythmias in a rat model of ischaemia-reperfusion. However, the effect of a differing time course of pretreatment has not been investigated. 104 Sprague-Dawley rats were randomised...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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SAGE Publications
2001-06-01
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| Series: | Journal of the Renin-Angiotensin-Aldosterone System |
| Online Access: | https://doi.org/10.3317/jraas.2001.014 |
| _version_ | 1797282022793674752 |
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| author | Bo-qing Zhu Yi-ping Sun Richard E Sievers Amanda EM Browne Randall J Lee Kanu Chatterjee William W Parmley |
| author_facet | Bo-qing Zhu Yi-ping Sun Richard E Sievers Amanda EM Browne Randall J Lee Kanu Chatterjee William W Parmley |
| author_sort | Bo-qing Zhu |
| collection | DOAJ |
| description | A previous study by our group showed that 10 weeks of pretreatment with losartan reduced myocardial infarct size and arrhythmias in a rat model of ischaemia-reperfusion. However, the effect of a differing time course of pretreatment has not been investigated. 104 Sprague-Dawley rats were randomised to four groups: a control, and three treatment groups in which losartan (40 mg/kg/day) was administered in drinking water for one day, one week, and four weeks respectively. After different durations of pretreatment, the rats were subjected to 17 minutes of left coronary artery occlusion and 120 minutes of reperfusion. Haemodynamic variables were not significantly different between the four groups. Myocardial infarct size was unchanged after one day and one week of pretreatment (52±7, 57±6% vs . control 55±3%), but was significantly reduced by four weeks of pretreatment with losartan (38±6, p<0.05). Endothelial-dependent vasorelaxation was significantly increased by four weeks of pretreatment (-81±4 vs . -62±7%, p<0.05). As an indicator of ischaemia, vascular endothelial growth factor (VEGF) levels in ischaemic myocardium were decreased after one and four weeks of pretreatment (0.75±0.05, 0.58±0.10 vs. 1.0, p<0.05, 0.01, respectively). In conclusion, losartan has time-dependent cardiovascular protective effects. Four weeks of pretreatment with losartan decreased infarct size and VEGF, and improved endothelial dysfunction. |
| first_indexed | 2024-03-07T17:05:58Z |
| format | Article |
| id | doaj.art-71bdfbca9c3841c2966d281df0737a76 |
| institution | Directory Open Access Journal |
| issn | 1470-3203 |
| language | English |
| last_indexed | 2024-03-07T17:05:58Z |
| publishDate | 2001-06-01 |
| publisher | SAGE Publications |
| record_format | Article |
| series | Journal of the Renin-Angiotensin-Aldosterone System |
| spelling | doaj.art-71bdfbca9c3841c2966d281df0737a762024-03-03T02:37:38ZengSAGE PublicationsJournal of the Renin-Angiotensin-Aldosterone System1470-32032001-06-01210.3317/jraas.2001.014Effects of different durations of pretreatment with losartan on myocardial infarct size, endothelial function, and vascular endothelial growth factorBo-qing ZhuYi-ping SunRichard E SieversAmanda EM BrowneRandall J LeeKanu ChatterjeeWilliam W ParmleyA previous study by our group showed that 10 weeks of pretreatment with losartan reduced myocardial infarct size and arrhythmias in a rat model of ischaemia-reperfusion. However, the effect of a differing time course of pretreatment has not been investigated. 104 Sprague-Dawley rats were randomised to four groups: a control, and three treatment groups in which losartan (40 mg/kg/day) was administered in drinking water for one day, one week, and four weeks respectively. After different durations of pretreatment, the rats were subjected to 17 minutes of left coronary artery occlusion and 120 minutes of reperfusion. Haemodynamic variables were not significantly different between the four groups. Myocardial infarct size was unchanged after one day and one week of pretreatment (52±7, 57±6% vs . control 55±3%), but was significantly reduced by four weeks of pretreatment with losartan (38±6, p<0.05). Endothelial-dependent vasorelaxation was significantly increased by four weeks of pretreatment (-81±4 vs . -62±7%, p<0.05). As an indicator of ischaemia, vascular endothelial growth factor (VEGF) levels in ischaemic myocardium were decreased after one and four weeks of pretreatment (0.75±0.05, 0.58±0.10 vs. 1.0, p<0.05, 0.01, respectively). In conclusion, losartan has time-dependent cardiovascular protective effects. Four weeks of pretreatment with losartan decreased infarct size and VEGF, and improved endothelial dysfunction.https://doi.org/10.3317/jraas.2001.014 |
| spellingShingle | Bo-qing Zhu Yi-ping Sun Richard E Sievers Amanda EM Browne Randall J Lee Kanu Chatterjee William W Parmley Effects of different durations of pretreatment with losartan on myocardial infarct size, endothelial function, and vascular endothelial growth factor Journal of the Renin-Angiotensin-Aldosterone System |
| title | Effects of different durations of pretreatment with losartan on myocardial infarct size, endothelial function, and vascular endothelial growth factor |
| title_full | Effects of different durations of pretreatment with losartan on myocardial infarct size, endothelial function, and vascular endothelial growth factor |
| title_fullStr | Effects of different durations of pretreatment with losartan on myocardial infarct size, endothelial function, and vascular endothelial growth factor |
| title_full_unstemmed | Effects of different durations of pretreatment with losartan on myocardial infarct size, endothelial function, and vascular endothelial growth factor |
| title_short | Effects of different durations of pretreatment with losartan on myocardial infarct size, endothelial function, and vascular endothelial growth factor |
| title_sort | effects of different durations of pretreatment with losartan on myocardial infarct size endothelial function and vascular endothelial growth factor |
| url | https://doi.org/10.3317/jraas.2001.014 |
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