Amer Mona G, Mohamed Nader M, Shaalan Aly A M
Department of Histology and Cell Biology, Faculty of Medicine, Zagazig University, Zagazig, Egypt.
Department of Pediatrics and Neonatology, Al Ahrar Hospital, Zagazig, Egypt.
Histol Histopathol. 2017 Dec;32(12):1293-1303. doi: 10.14670/HH-11-883. Epub 2017 Feb 20.
Intrauterine growth restriction (IUGR) has been linked to heart disease in adulthood. This study aimed to examine the effect of gestational protein restriction during fetal and early postnatal life on the cardiac muscle structure and function in adult offspring. Pregnant female rats were randomly divided into two dietary groups: normal-protein diet (NP) and low-protein diet (LP). Fifteen male offspring from each group were included in the study. Offspring body weights were recorded at birth and monthly from weaning until 24 weeks of age while systolic blood pressure was measured weekly. At the end of the experiment, hearts were weighed and processed for light and electron microscopy and immunohistochemical study. Immunohistochemical staining for localization of inducible nitric oxide synthase (iNOS) and connexin 43 proteins was performed. The gestational protein restriction induced deleterious effects on adult offspring including decreased birth weight, heart weight, and heart rate, and increased systolic blood pressure. Histologically, the number of cardiomyocytes decreased and cardiac fibrosis increased. Signs of degeneration at both structural and ultra-structural levels of cardiomyocytes were also seen. The iNOS was up regulated in LP offspring which was a promoter for apoptosis, while connexin 43 was down regulated which would affect heart conductivity and contractility. Our results demonstrate that adult offspring body weight and cardiac muscle structure and function can be programmed by maternal gestational nutrition. These adverse outcomes suggest the criticality of dietary behavior during pregnancy on long-term offspring cardiac health.
宫内生长受限（IUGR）与成年后的心脏病有关。本研究旨在探讨胎儿期和出生后早期蛋白质摄入受限对成年子代心肌结构和功能的影响。将怀孕的雌性大鼠随机分为两组饮食组：正常蛋白质饮食（NP）和低蛋白质饮食（LP）。每组纳入15只雄性子代进行研究。记录子代出生时的体重，并从断奶后每月记录一次，直至24周龄，同时每周测量收缩压。实验结束时，称量心脏重量，并进行光镜、电镜及免疫组化研究。进行诱导型一氧化氮合酶（iNOS）和连接蛋白43蛋白定位的免疫组化染色。孕期蛋白质摄入受限对成年子代产生了有害影响，包括出生体重、心脏重量和心率降低，以及收缩压升高。组织学上，心肌细胞数量减少，心脏纤维化增加。在心肌细胞的结构和超微结构水平上也可见到退变迹象。LP子代中iNOS上调，这是细胞凋亡的促进因素，而连接蛋白43下调，这会影响心脏的传导性和收缩性。我们的结果表明，成年子代的体重以及心肌结构和功能可由母体孕期营养编程。这些不良后果表明孕期饮食行为对后代长期心脏健康至关重要。
