Spontaneous and induced alterations in the cardiac membranous ventricular septum of fetal, weanling, and adult rats

摘要: Alterations of the cardiac membranous ventricular septum were studied using macrodissection, scanning electron and light microscopy fetal, weanling, adult Sprague-Dawley rats. Membranous septal defects (VSDs) observed in 2.0% fetuses on day 21 postcoitus (pc) but not weanling or The most common observation was a nonpatent depression with an incidence 38.1, 10.5, 4.3% for days 17, 19, pc, respectively, 11.8% weanlings, 9.1% adults. VSDs characterized by split endocardial cushion cells interventricular component septum. Nonpatent depressions atrioventricular septum, they persisted postnatally as blind-ended diverticulum directed above tricuspid valve. cardiovascular teratogens, trimethadione trypan blue, produced morphologically similar to untreated fetuses. Maternal diet restriction (25% controls) lowered fetal (day pc) body weight 47% did affect alterations, suggesting that intrauterine growth retardation is necessarily associated alterations development We conclude neither nor rats postnatal survival close spontaneously during neonatal life.