Effects of Relaxin on Cardiac Performance and Coronary Artery Reactivity in Aged Spontaneously Hypertensive Female Rats
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University of Akron / OhioLINK
2014
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ndltd-OhioLink-oai-etd.ohiolink.edu-akron14011895442021-08-03T06:25:03Z Effects of Relaxin on Cardiac Performance and Coronary Artery Reactivity in Aged Spontaneously Hypertensive Female Rats McCarthy, Joseph C. Health Sciences Biomedical Research Medicine Biology Physiology Hypertension cardiovascular disease Postmenopausal females hormone replacement therapy Relaxin isolated hearts langendorff procedure coronary arteries coronary vascular function cardiac performance myogenic response SHR Women have decreased risk of cardiovascular disease compared to men until after menopause when the risk is similar between men and women. Hypertension is prevalent in one out of three adults in the United States. Postmenopausal women have a higher risk of hypertension compared to men of similar age and premenopausal women. Relaxin (RLX) is a vasodilatory hormone that has shown to have cardioprotective effects. To investigate this effect, contractility of the heart, relaxation of the heart, coronary flow, and isolated septal coronary arteries responses to relaxin (RLX) were assessed. I tested the hypotheses that relaxin administration to aged (18 months) spontaneously hypertensive female rats (SHR), improves coronary vascular function and improves cardiac performance. An osmotic pump containing recombinant human relaxin (rhRLX) was placed subcutaneously above the aged female SHR’s right shoulder for 5-7 days. Data collected was compared to aged SHR vehicle (VEH) group (control). Left ventricular contractility, left ventricular relaxation, and coronary flow were examined using the Langendorff apparatus. Septal coronary arteries were assessed using a pressure arteriograph. Active and passive diameters of the septal coronary artery were examined over a range of pressures ranging from 10-100 mmHg and percent tone was calculated. Relaxin treated SHR’s showed a decreased contractility, relaxation, coronary flow, and percent tone of septal coronary arteries compared to old SHR vehicles. In conclusion, relaxin improves cardiac behavior and coronary vascular function in aged spontaneously hypertensive rats. Decreased contractility, relaxation, and coronary flow may be beneficial for aged hypertensive hearts because the heart can work more efficiently. Decreased myogenic response of the coronary arteries may result in a vasodilatory coronary circulation. 2014 English text University of Akron / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=akron1401189544 http://rave.ohiolink.edu/etdc/view?acc_num=akron1401189544 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws. |
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NDLTD |
| language |
English |
| sources |
NDLTD |
| topic |
Health Sciences Biomedical Research Medicine Biology Physiology Hypertension cardiovascular disease Postmenopausal females hormone replacement therapy Relaxin isolated hearts langendorff procedure coronary arteries coronary vascular function cardiac performance myogenic response SHR |
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Health Sciences Biomedical Research Medicine Biology Physiology Hypertension cardiovascular disease Postmenopausal females hormone replacement therapy Relaxin isolated hearts langendorff procedure coronary arteries coronary vascular function cardiac performance myogenic response SHR McCarthy, Joseph C. Effects of Relaxin on Cardiac Performance and Coronary Artery Reactivity in Aged Spontaneously Hypertensive Female Rats |
| author |
McCarthy, Joseph C. |
| author_facet |
McCarthy, Joseph C. |
| author_sort |
McCarthy, Joseph C. |
| title |
Effects of Relaxin on Cardiac Performance and Coronary Artery Reactivity in Aged Spontaneously Hypertensive Female Rats |
| title_short |
Effects of Relaxin on Cardiac Performance and Coronary Artery Reactivity in Aged Spontaneously Hypertensive Female Rats |
| title_full |
Effects of Relaxin on Cardiac Performance and Coronary Artery Reactivity in Aged Spontaneously Hypertensive Female Rats |
| title_fullStr |
Effects of Relaxin on Cardiac Performance and Coronary Artery Reactivity in Aged Spontaneously Hypertensive Female Rats |
| title_full_unstemmed |
Effects of Relaxin on Cardiac Performance and Coronary Artery Reactivity in Aged Spontaneously Hypertensive Female Rats |
| title_sort |
effects of relaxin on cardiac performance and coronary artery reactivity in aged spontaneously hypertensive female rats |
| publisher |
University of Akron / OhioLINK |
| publishDate |
2014 |
| url |
http://rave.ohiolink.edu/etdc/view?acc_num=akron1401189544 |
| work_keys_str_mv |
AT mccarthyjosephc effectsofrelaxinoncardiacperformanceandcoronaryarteryreactivityinagedspontaneouslyhypertensivefemalerats |
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