title: In Utero Exposure to a Cardiac Teratogen Causes Reversible Deficits in Postnatal Cardiovascular Function, But Altered Adaptation to the Burden of Pregnancy.
abstract: Congenital heart defects (CHD) are the most common birth anomaly and while many resolve spontaneously by 1 year of age, the lifelong burden on survivors is poorly understood. Using a rat model of chemically induced CHD that resolve postnatally, we sought to characterize the postnatal changes in cardiac function, and to investigate whether resolved CHD affects the ability to adapt to the increased the cardiovascular (CV) burden of pregnancy. To generate rats with resolved CHD, pregnant rats were administered distilled water or dimethadione (DMO) [300 mg/kg b.i.d. on gestation day (gd) 9 and 10] and pups delivered naturally. To characterize structural and functional changes in the heart, treated and control offspring were scanned by echocardiography on postnatal day 4, 21, and 10-12 weeks. Radiotelemeters were implanted for continuous monitoring of hemodynamics. Females were mated and scanned by echocardiography on gd12 and gd18 during pregnancy. On gd18, maternal hearts were collected for structural and molecular assessment. Postnatal echocardiography revealed numerous structural and functional differences in treated offspring compared with control; however, these resolved by 10-12 weeks of age. The CV demand of pregnancy revealed differences between treated and control offspring with respect to mean arterial pressure, CV function, cardiac strain, and left ventricular gene expression. In utero exposure to DMO also affected the subsequent generation. Gd18 fetal and placental weights were increased in treated F2 offspring. This study demonstrates that in utero chemical exposure may permanently alter the capacity of the postnatal heart to adapt to pregnancy and this may have transgenerational effects.
authors: *Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada K7L 3N6 and Analytics for Life, Toronto, Ontario, Canada M5B 1N8.
authors: Kristiina L
authors: KL
authors: Aasa
authors: *Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada K7L 3N6 and Analytics for Life, Toronto, Ontario, Canada M5B 1N8.
authors: Rebecca D
authors: RD
authors: Maciver
authors: *Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada K7L 3N6 and Analytics for Life, Toronto, Ontario, Canada M5B 1N8.
authors: Shyamlal
authors: S
authors: Ramchandani
authors: *Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada K7L 3N6 and Analytics for Life, Toronto, Ontario, Canada M5B 1N8.
authors: Michael A
authors: MA
authors: Adams
authors: *Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada K7L 3N6 and Analytics for Life, Toronto, Ontario, Canada M5B 1N8 ozolinst@queensu.ca.
authors: Terence R S
authors: TR
authors: Ozolinš
mesh_terms: D000818:Animals; D001724:Birth Weight / Q000187:drug effects; D054715:Cardiotoxins / Q000633:toxicity; D002319:Cardiovascular System / Q000187:drug effects / Q000503:physiopathology*; D004114:Dimethadione / Q000633:toxicity; D004195:Disease Models, Animal; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D006330:Heart Defects, Congenital / Q000139:chemically induced / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology*; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D006439:Hemodynamics / Q000187:drug effects; D008297:Male; D008431:Maternal-Fetal Exchange; D010929:Placentation / Q000187:drug effects; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology*; D011897:Random Allocation; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function; D013723:Teratogens / Q000633:toxicity; D014463:Ultrasonography
chemical_list: D054715:Cardiotoxins; D013723:Teratogens; D004114:Dimethadione
keywords: cardiovascular; congenital heart defect; pregnancy; teratogen