Premium
Reduced Myocardial Apoptosis May Be Responsible for Attenuated Decline in Left Ventricular Systolic Function in Female Compared to Male Postinfarcted Middle‐Aged Rats
Author(s) -
Pavliak Kristina,
Chen YueFeng,
Pingitore Alessandro,
Dedkov Eduard
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.555.1
Subject(s) - medicine , cardiac function curve , ejection fraction , cardiology , stroke volume , myocyte , endocrinology , myocardial infarction , heart failure
Our previous study on post‐MI male and female middle‐aged rats has revealed that although both sexes had a similar scale of LV remodeling, the females showed a greater density of cardiac myocytes in the epimyocardium. However, the mechanism of this structural alteration, as well as its impact on LV function, remained unclear. Our current study was aimed at determining whether the sex‐specific difference in the density of cardiac myocytes is related to the rate of their death and whether it affects the cardiac performance in post‐MI rats. A large MI was induced in 12‐month‐old male (M‐MI) and female (F‐MI) Sprague‐Dawley rats by ligation of the left coronary artery. The cardiac function was monitored for two months post‐MI. At the end of the experiment, various LV parameters were compared between sexes. We found that although both groups had a similar pattern of decline in LV function, the F‐MI rats exhibited a less deteriorated cardiac performance compared to M‐MI rats, as indicated by the values of stroke volume (0.18±0.01 vs. 0.14±0.02 mL, P<0.05), ejection fraction (39.9±3.4 vs. 26.7±7.7 %, P<0.05) and cardiac output (57.8±3.1 vs. 44.6±8.7 mL/min, P<0.05). Moreover, the F‐MI rats displayed a higher density of cardiac myocytes in the epimyocardium than the males (2383.8±242.6 vs. 1785.7±55.9 cells/mm 2 , P<0.05). This was associated with a lower rate of myocyte apoptosis in the F‐MI rats (0.18±0.08 vs. 0.91±0.30 apoptotic cells/mm 2 , P<0.01). Thus, our data showed that the F‐MI rats had a better preserved LV function compared to M‐MI rats, and that this might be caused by an increased myocyte survival in females.