Send to

Choose Destination
See comment in PubMed Commons below
Am J Physiol Heart Circ Physiol. 2004 Mar;286(3):H1107-13. Epub 2003 Nov 26.

Mechanisms of ADRF release from rat aortic adventitial adipose tissue.

Author information

  • 1Franz Volhard Clinic, Wiltbergstrasse 50, 13125 Berlin, Germany.


Blood vessels are surrounded by variable amounts of adipose tissue. We showed earlier that adventitial adipose tissue inhibits rat aortic contraction by release of a transferable factor, adventitium-derived relaxing factor (ADRF), which activates smooth muscle K(+) channels. However, little is known about the mechanisms of ADRF release. Using isolated rat aortic rings and isometric contraction measurements, we show that ADRF release depends on extracellular [Ca(2+)] (EC(50) approximately 4.7 mM). ADRF effects do not involve neuronal presynaptic N-type Ca(2+) and Na(+) channels or vanilloid, cannabinoid, and CGRP receptors. ADRF release is strongly inhibited by the protein tyrosine kinase inhibitors genistein and tyrphostin A25. In contrast, daidzein, an inactive genistein analog, and the protein tyrosine kinase inhibitor ST638 had no effect. Protein kinase A inhibition by H89 also inhibited ADRF release, whereas the protein kinase G inhibitor KT-5823 had no effect. We propose that ADRF release is Ca(2+) dependent and is regulated by intracellular signaling pathways involving tyrosine kinase and protein kinase A. Furthermore, ADRF release does not depend on perivascular nerve endings.

[PubMed - indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Write to the Help Desk