ABC | Volume 112, Nº2, February 2019

Original Article Maifrino et al Exercise effects on ovariectomized mice Arq Bras Cardiol. 2019; 112(2):180-188 physical training knockout groups showed to be statistically increased in +7,8% (Figure 7). Discussion The main objective of this study was to verify the effects of moderate aerobic training on the ascending aorta of ovariectomized female mice, knockout for the low-density lipoprotein receptor LDL through the analyses of types I and III collagen fibers, the expression of 8-OHdG oxidative stress markers of MMP-2 and MMP-9 metalloproteinases. Collagen and elastin are major structural and functional components of the arterial wall. These components actively participate in arterial wall remodeling in response to hemodynamic alterations and during atherogenesis. The histopathological analysis did not show any morphological changes in the control group. However, the LDL KO group showed increased thickness and larger spacing between the elastic fibers. Some studies have demonstrated an association between an increase in intima-media thickness and the occurrence of cardiac events, 28 which confirmed the existence of the association between increased intima-media thickness of the carotid and the presence of cardiovascular risk factors, including infection and inflammation markers. Collagen I is mostly a structural collagen; collagen III, in turn, is more frequent in pathological processes. Our results have shown that the number of cells in apoptosis were significantly lower in the control group and remained constant in the Control groups (OS-C and OT-C) and the LDL knockout groups (S-LDL KO, OS-LDL KO and OT-LDL KO), without significant Figure 6 – Photomicrographs of cross-sections of the ascending aorta of mice submitted to immunohistochemical reaction for MMP-9. Note the presence of immunoexpression in all layers, heterogeneously, in all groups. Calibration bar: 100 µm. Figure 7 – Relative frequency (%) of apoptotic cells in the ascending aorta of the control sedentary group (S-C) vs. the different evaluated groups as evidenced by the TUNEL assay. *p < 0,05 vs. S-C, #p < 0,05 vs. OS-C, +p < 0,05 vs. OS-LDL-KO. Values are expressed as mean ± SD (p < 0,05). 35 30 25 15 5 20 10 0 OS-C OT-C S-LDL-KO OS-LDL-KO OT-LDL-KO * *# *# *# *#+ Apoptosis (%) relation to control S-C 185