title: Exposure to the opioid antagonist naltrexone throughout gestation alters postnatal heart development.
abstract: The influence of endogenous opioid blockade by naltrexone during prenatal life on postnatal heart development was studied in rats. Pregnant Sprague-Dawley rats received daily injections of 50 mg/kg naltrexone (NTX) or saline throughout gestation; offspring were cross-fostered at birth to mothers not receiving NTX. In general, NTX-treated offspring weighed more than controls throughout preweaning life, whereas heart weights were often increased from age-matched controls up to 35 days. Biochemical analyses of nucleic acids and protein demonstrated that DNA and protein content were increased throughout development in NTX-treated animals relative to controls. Morphometric analyses revealed increases in total area of the heart and myocardial area in NTX-exposed rats relative to control levels. These data suggest that endogenous opioids function to regulate cardiac growth during the prenatal period, and that disruption of this process has long-term implication for cardiac biology.
authors.affiliation: Department of Neuroscience and Anatomy, The Milton S. Hershey Medical Center, Pennsylvania State University, Hershey, Pa 17033-0850, USA. pxm9@psu.edu
authors.forename: Patricia J
authors.initials: PJ
authors.lastname: McLaughlin
mesh_terms: D000375:Aging; D000818:Animals; D001835:Body Weight; D004247:DNA / Q000032:analysis; D005260:Female; D005865:Gestational Age; D006321:Heart / Q000033:anatomy & histology / Q000196:embryology / Q000254:growth & development*; D008098:Litter Size; D008297:Male; D009206:Myocardium / Q000737:chemistry; D009271:Naltrexone / Q000008:administration & dosage*; D009292:Narcotic Antagonists / Q000008:administration & dosage*; D018847:Opioid Peptides / Q000502:physiology; D009929:Organ Size; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D011506:Proteins / Q000032:analysis; D012313:RNA / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D009292:Narcotic Antagonists; D018847:Opioid Peptides; D011506:Proteins; D009271:Naltrexone; D012313:RNA; D004247:DNA