Endothelium dependency of contractile activity differs in infant and adult vertebral arteries

J Clin Invest. 1994 Mar;93(3):1339-43. doi: 10.1172/JCI117093.

Abstract

Contractions to serotonin (5-HT) and endothelin-1 (ET-1) in infant (0-2 yr) and adult (38-71 yr) vertebral arteries were examined in the presence of either the cyclooxygenase inhibitor indomethacin or NG-monomethyl-L-arginine (L-NMMA), an inhibitor of nitric oxide production. In addition, endothelium-dependent relaxations to acetylcholine were characterized in arteries contracted with agonist. The results showed that: (a) Contractions of infant arteries to 5-HT or ET-1 decreased to 44 +/- 8% and 27 +/- 13%, respectively, within 10 min. Indomethacin or removal of endothelium abolished this decreased response, whereas L-NMMA had no effect. (b) Adult arteries produced sustained contractions to 5-HT or ET-1 that were unaffected by indomethacin, endothelium denudation, or L-NMMA. (c) Endothelium-dependent relaxations to acetylcholine were greater in infant than adult arteries and were abolished by indomethacin (but not L-NMMA) in infants and L-NMMA (but not indomethacin) in adults. Thus, endothelium-dependent responses in infant arteries are attenuated because of increased prostaglandin activity not observed in adult tissues. Additionally, there is an age-dependent change in the primary mechanism responsible for acetylcholine-induced vasodilation. Apparently, endothelium dependency of acetylcholine-induced relaxation is highly dependent on cyclooxygenase activity in the infant vertebral artery, but in the adult artery, nitric oxide is linked to the vasodilator response.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Age Factors
  • Aged
  • Arginine / analogs & derivatives
  • Arginine / pharmacology
  • Child, Preschool
  • Endothelins / pharmacology
  • Endothelium, Vascular / physiology*
  • Female
  • Humans
  • In Vitro Techniques
  • Infant
  • Infant, Newborn
  • Male
  • Middle Aged
  • Serotonin / pharmacology
  • Vasoconstriction*
  • Vertebral Artery / physiology*
  • omega-N-Methylarginine

Substances

  • Endothelins
  • omega-N-Methylarginine
  • Serotonin
  • Arginine