Related Experiment Video
Updated: May 5, 2026

Using In Vivo and Tissue and Cell Explant Approaches to Study the Morphogenesis and Pathogenesis of the Embryonic and Perinatal Aorta
Published on: September 12, 2017
Endothelium dependency of contractile activity differs in infant and adult vertebral arteries
J R Charpie1, K D Schreur, S M Papadopoulos
1Department of Pediatric Cardiology, University of Michigan Medical School, Ann Arbor 48109-0622.
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.
More Related Videos
10:28Evaluation of Vascular Control Mechanisms Utilizing Video Microscopy of Isolated Resistance Arteries of Rats
Published on: December 5, 2017
08:41Assessment of Vascular Tone Responsiveness using Isolated Mesenteric Arteries with a Focus on Modulation by Perivascular Adipose Tissues
Published on: June 3, 2019
Related Concept Videos
Blood Flow
Smooth Muscle Contraction
The onset of contraction is triggered by an increase in calcium ions within the sarcoplasm, similar to the process in striated muscle. However, smooth muscles have a relatively smaller reservoir of the sarcoplasmic...
Structure of Blood Vessels
Arteries and Arterioles
Veins as Blood Reservoirs
Autoregulation of Blood Flow
Chemical Signaling in Autoregulation
Chemical signaling operates at the precapillary sphincter level, inciting either contraction or relaxation....