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Periadventitial fat releases a vascular relaxing factor

Item Type:Article
Title:Periadventitial fat releases a vascular relaxing factor
Creators Name:Loehn, M. and Dubrovska, G. and Lauterbach, B. and Luft, F.C. and Gollasch, M. and Sharma, A.M.
Abstract:Virtually all blood vessels are surrounded by adventitial fat. Adipocytes produce a host of vasoactive substances that may influence vascular contraction. We tested whether or not perivascular adipose tissue modulates contraction of aortic ring preparations. We studied aortic rings surrounded by periadventitial adipose tissue from adult Sprague-Dawley rats. At a maximum concentration of 300 nM angiotensin II, 6.5 {mu}M serotonin, and 5 {mu}M phenylephrine, the contractile response of intact rings was 95%, 80%, and 30% lower than that of vessels without periadventitial fat. The anticontractile effect of periadventitial fat was reduced by inhibition of ATP-dependent K+ channels with glibenclamide (3 {mu}M) and by the tyrosine kinase inhibitor genistein (10 {mu}M). Blocking NOS, cyclo-oxygenase, cytochrome P450, or adenosine receptors did not restore the vascular response in intact vessels. The anticontractile effect of perivascular fat was present in Zucker fa/fa rats, suggesting that leptin receptors were not responsible. Transferring the bath solution from intact vessels, isolated periadventitial tissue, and cultured rat adipocytes to precontracted vessels lacking periadventitial fat resulted in a rapid relaxation. We suggest that perivascular adventitial adipose tissue releases a transferable adventitium-derived relaxing factor that acts by tyrosine kinase-dependent activation of K+ channels in vascular smooth muscle cells.—Loehn, M., Dubrovska, G., Lauterbach, B., Luft, F. C., Gollasch, M., Sharma, A. M. Periadventitial fat releases a vascular relaxing factor.
Keywords:Fat, Adventitium, Ion Channels, Tyrosine Phosphorylation, Animals, Mice, Rats
Source:FASEB Journal
Publisher:Federation of American Societies for Experimental Biology
Page Range:1057-1063
Date:July 2002
Official Publication:https://doi.org/10.1096/fj.02-0024com
PubMed:View item in PubMed

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