Nerve-perivascular fat communication as a potential influence on the performance of blood vessels used as coronary artery bypass grafts

Abstract

Perivascular fat, the cushion of adipose tissue surrounding blood vessels, possesses dilator, anti-contractile and constrictor actions. The majority of these effects have been demonstrated in vitro and may depend on the vessel and/or the experimental method or species used. In general, the relaxant effect of perivascular adipose tissue is local and may be either endothelium-dependent or endothelium-independent. However, nerve stimulation studies show that, in general, perivascular adipose tissue (PVAT) has an anti-contractile vascular effect likely to involve an action of the autonomic vascular nerves. Apart from a direct effect of perivascular fat-derived factors on bypass conduits, an interaction with a number of neurotransmitters and other agents may play an important role in graft performance. Although the vascular effects of PVAT are now well-established there is a lack of information regarding the role and/or involvement of peripheral nerves including autonomic nerves. For example, are perivascular adipocytes innervated and does PVAT affect neuronal control of vessels used as grafts? To date there is a paucity of electrophysiological studies into nerve-perivascular fat control. This review provides an overview of the vascular actions of PVAT, focussing on its potential relevance on blood vessels used as bypass grafts. In particular, the anatomical relationship between the perivascular nerves and fat are considered and the role of the perivascular-nerve/fat axis in the performance of bypass grafts is also discussed.

Renal perivascular adipose tissue: Form and function

“…17, 29) and reports from the 1970s suggest that mesenteric fat adipocytes may be sparsely innervated (22). A recent review by Loesch and Dashwood (40) brings together our current knowledge and questions with respect to innervation of PVAT. To our knowledge, no formal, systematic study of at least the sympathetic nervous system innervation of any PVAT has been done.…”

Preserved Vasoconstriction and Relaxation of Saphenous Vein Grafts Obtained by a No-Touch Technique for Coronary Artery Bypass Grafting

“…24 In addition, autonomic vasomotor functions are relatively intact in SVGs with PVAT because perivascular nerves are distributed within PVAT. 25,26 The sympathetic control with neurotransmitters, including noradrenaline, could be involved in the strong contraction. Therefore, in NT, it seems that micro blood vessels and nerves around SVGs are preserved, so reactivity and sensitivity to drugs may be preserved as compared with the CON group.…”

“…This study was performed with reference to previous research. [22][23][24][25] After collection, the SVG tissue was divided into NT and CON groups, in vascular rings measuring 3 mm in length, and placed on a stainless-steel hook in an organ chamber containing 5 mL of Krebs-Henseleit solution at 37°C while blowing in Carbogen (5% CO2 in O2). The blood vessel was set to a tension of 9.8 mN and equilibrated for ∼30 min.…”

Biomaterial‐Induction of a Transplantable Angiosome

“…It has been shown that stimulation by nonangiogenic protein (Fibroblast growth factor 9) during angiogenesis creates robust long lasting microvessels by stimulating the perivascular cells from the tunica adventitia and tunica media . Subsequently, several studies have confirmed an important role for perivascular tissue in new vessel development . Given the striking importance of perivascular tissue and the relatively small knowledge as to interactions between the perivascular tissue and biomaterials, we sought to investigate how a well‐characterized calcium phosphate bioceramic would interact with the tunica adventitia of a femoral vein.…”