title: Oxygenation decreases elastin secretion from rat ductus arteriosus smooth muscle cells.
abstract: BACKGROUND
  The ductus arteriosus (DA), a fetal arterial connection between the main pulmonary artery and the descending aorta, normally closes immediately after birth. The oxygen concentration in the blood rises after birth, and in the DA this increase in oxygen concentration causes functional closure, which is induced by smooth muscle contraction. Previous studies have demonstrated that hypoxia and/or oxygenation affect vascular remodeling of various vessels. Therefore, we hypothesized that the rise in oxygen concentration would affect the vascular structure of the DA due to production of proteins secreted from DA smooth muscle cells (SMC).
  
  
  RESULTS
  Liquid chromatography-tandem mass spectrometry was used to comprehensively investigate the secreted proteins in the supernatant of rat DA SMC harvested under hypoxic conditions (1% oxygen) or under normoxic conditions (21% oxygen). We found that the rise in oxygen concentration reduced the secretion of elastin from DA SMC. On reverse transcription-polymerase chain reaction, the expression of elastin mRNA was not significantly changed in DA SMC from hypoxic to normoxic conditions.
  
  
  CONCLUSIONS
  Given that elastin forms internal elastic lamina and elastic fibers in the vascular muscle layers, and that a rise in oxygen concentration reduced the secretion of elastin, this suggests that the rise in blood oxygen concentration after birth reduces the secretion of elastin, and therefore may play a role in DA structural remodeling after birth.
authors.affiliation: Department of Life Science and Medical Bioscience, Waseda University, Tokyo, Japan.
authors.forename: Shoji
authors.initials: S
authors.lastname: Kawakami
authors.affiliation: Department of Life Science and Medical Bioscience, Waseda University, Tokyo, Japan.|Department of Cell Physiology, Jikei University, Tokyo, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Minamisawa
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D004195:Disease Models, Animal; D004373:Ductus Arteriosus / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D004549:Elastin / Q000096:biosynthesis / Q000235:genetics*; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D018507:Gene Expression Regulation, Developmental; D000860:Hypoxia / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D009131:Muscle, Smooth, Vascular / Q000196:embryology / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology*; D011247:Pregnancy; D011270:Pregnancy, Animal; D012313:RNA / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D066253:Vascular Remodeling / Q000235:genetics
chemical_list: D012313:RNA; D004549:Elastin; D010100:Oxygen
keywords: ductus arteriosus; elastin; hypoxia; liquid chromatography-tandem mass spectrometry; oxygen