Hypertrophy signaling during peripartum cardiac remodeling

Gonzalez, Amanda; Osorio, Juan C.; Manlhiot, Cedric; Gruber, Dorota; Homma, Shunichi; Mital, Seema

doi:10.1152/ajpheart.00401.2007

Cited by 33 publications

(36 citation statements)

References 24 publications

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“…However, none of the parameters measured supported the evidence of significant cardiac hypertrophy in pregnant Wistar rats. These findings are in contrast to some other studies performed in rats [2], [18]–[20], but in line with our previous study in Wistar rats [8]. Our present study had 80% statistical power to detect an increase in HW of 13% due to pregnancy.…”

Section: Discussionsupporting

confidence: 87%

Effect of Transverse Aortic Constriction on Cardiac Structure, Function and Gene Expression in Pregnant Rats

et al. 2014

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BackgroundThere is an increased risk of heart failure and pulmonary edema in pregnancies complicated by hypertensive disorders. However, in a previous study we found that pregnancy protects against fibrosis and preserves angiogenesis in a rat model of angiotensin II induced cardiac hypertrophy. In this study we test the hypothesis that pregnancy protects against negative effects of increased afterload.MethodsPregnant (gestational day 5.5–8.5) and non-pregnant Wistar rats were randomized to transverse aortic constriction (TAC) or sham surgery. After 14.2±0.14 days echocardiography was performed. Aortic blood pressure and left ventricular (LV) pressure-volume loops were obtained using a conductance catheter. LV collagen content and cardiomyocyte circumference were measured. Myocardial gene expression was assessed by real-time polymerase chain reaction.ResultsHeart weight was increased by TAC (p<0.001) but not by pregnancy. Cardiac myocyte circumference was larger in pregnant compared to non-pregnant rats independent of TAC (p = 0.01), however TAC per se did not affect this parameter. Collagen content in LV myocardium was not affected by pregnancy or TAC. TAC increased stroke work more in pregnant rats (34.1±2.4 vs 17.5±2.4 mmHg/mL, p<0.001) than in non-pregnant (28.2±1.7 vs 20.9±1.5 mmHg/mL, p = 0.06). However, it did not lead to overt heart failure in any group. In pregnant rats, α-MHC gene expression was reduced by TAC. Increased in the expression of β-MHC gene was higher in pregnant (5-fold) compared to non-pregnant rats (2-fold) after TAC (p = 0.001). Nine out of the 19 genes related to cardiac remodeling were affected by pregnancy independent of TAC.ConclusionsThis study did not support the hypothesis that pregnancy is cardioprotective against the negative effects of increased afterload. Some differences in cardiac structure, function and gene expression between pregnant and non-pregnant rats following TAC indicated that afterload increase is less tolerated in pregnancy.

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Section: Discussionsupporting

confidence: 87%

Effect of Transverse Aortic Constriction on Cardiac Structure, Function and Gene Expression in Pregnant Rats

et al. 2014

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“…In late-pregnant mice, an increase in heart weight but a decrease in the heart-to-body weight ratio was observed [18]. In 16-daypregnant rats, there was no significant change in heart-tobody weight when compared to nonpregnant rats (estrus cycle stage unknown) [24], while in this study we found that in late-pregnant rats (18-21 days) the heart-to-body weight ratio increased when compared to nonpregnant (diestrus) and postpartum animals.…”

Section: Discussionmentioning

confidence: 95%

Passive mechanical properties of cardiac tissues in heart hypertrophy during pregnancy

et al. 2009

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We evaluated changes in passive mechanical properties in cardiac tissues during rat pregnancy. Left and right ventricular free walls were dissected from hearts of nonpregnant, late-pregnant, and postpartum rats. Mechanical experiments in ventricular strips were done by stretch-release cycles using a step motor. The results show that during pregnancy, there is cardiac hypertrophy associated with (1) an increase in myocyte size, particularly of augmented myocyte length, (2) a decrease in passive tension developed by the myocardial walls, and (3) a decrease in both elastic modulus and hysteresis. All changes observed during rat pregnancy were reversed during postpartum. In conclusion, a heart with less ventricular rigidity could contribute to facilitating the ventricular filling in conditions of a greater circulating volume characteristic of pregnancy.

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“…Recent studies have shown there is a unique system of molecular signaling pathway involved in pregnancy-induced hypertrophy [22–24]. The ubiquitin-proteasome system is known to play an important role in the degradation of damaged and misfolded proteins in the heart [25].…”

Section: Discussionmentioning

confidence: 99%

Quantitative evaluation of longitudinal strain in layer-specific myocardium during normal pregnancy in China

Cong

Wang

Jin³

et al. 2016

Cardiovasc Ultrasound

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BackgroundThe myocardial wall of the left ventricle is a complex, multilayered structure and is not homogenous. The aim of this study was to determine longitudinal strain (LS) in the three myocardial layers in normal pregnant women according to gestation proceedings.MethodsThe advanced two-dimensional speckle tracking echocardiography (2D STE) was performed on 62 women during each pregnancy trimester and 6 to 9 weeks after delivery, while 30 age-matched, healthy, nonpregnant women served as controls. LS on endocardial, mid-myocardial and epicardial layers at 18 cardiac segments were measured.ResultsAs gestation proceeded, all of layer-specific LS and global LS progressively decreased, which subsequently recovered postpartum (P < 0.05), and the LS gradient between inner and outer myocardium became greater, which reached its maximum in the late pregnancy. Peak systolic LS was the highest at endocardium and the lowest at epicardium, while the highest at the apical level and the lowest at the base (P < 0.05). In the early pregnancy and postpartum, LS at basal level was homogenous, meanwhile layer-specific LS showed significant differences at mid-ventricular and apical level throughout the progress of normal pregnancy (P < 0.05).ConclusionsUsing 2D STE, three-layer assessment of LS can be performed in pregnant women and shall give us new insights into the quantitative analysis of global and regional LV function during pregnancy. Future studies on the detection of pregnancy related heart disease would require these parameters as reference values for each time point of a normal pregnancy.

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Hypertrophy signaling during peripartum cardiac remodeling

Cited by 33 publications

References 24 publications

Effect of Transverse Aortic Constriction on Cardiac Structure, Function and Gene Expression in Pregnant Rats

Effect of Transverse Aortic Constriction on Cardiac Structure, Function and Gene Expression in Pregnant Rats

Passive mechanical properties of cardiac tissues in heart hypertrophy during pregnancy

Quantitative evaluation of longitudinal strain in layer-specific myocardium during normal pregnancy in China

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