0229 : Effect of exercise training on crosstalk between vascular and perivascular adipose tissue: preliminary results

Abstract

Perivascular adipose tissue (PVAT) surrounds blood vessels and is considered as active endocrine organ which interact with endothelium and vascular smooth muscle cells in a paracrine way. Exercise training is widely known to modulate vascular function, and despite exercise has been also demonstrated to alter subcutaneous or visceral adipose tissue phenotype, the link between adipose tissue and vasomotor function in this context has never been challenged. Thus, the aim of our study was to explore whether the impact of exercise training on PVAT contributes to its effect on arterial function. Rats were exercised (40min/day 5 days/week for 5 weeks) or not. Aortic tissue was isolated and PVAT surrounded aorta excised and incubated for 30min before the isometric tension studies in Krebs solution (PVAT-incubated solution). Vasoreactivity to phenylephrine and acetylcholine was assessed on isolated aortic rings in presence or not of PVAT-incubated solution. Since, the presence or not of the vessel during the incubation of the PVAT could contribute to explain some discrepancy in the literature, we incubated PVAT in presence or not of the aortic tissue. Whatever the conditions, in sedentary rats, PVAT exacerbated the contractile response to phenylephrine and reduced the vasodilatory response to acetylcholine. An interesting point was that when the procedure was applied in aortic tissue and PVAT of exercise trained rats, both the pro-contractile effects and the anti-vasorelaxant effect of PVAT were blunted. In conclusion, we demonstrated here that moderate exercise training was able to limit the deleterious effect of PVAT on arterial vasoreactivity. These results could be attributed to effects of exercise either on aortic wall or on the endocrine function of PVAT. Both will be next explored (aortic sensitivity to phenylephrine and to acetylcholine, eNOS activation state and proteome profile of adipokines secreted by PVAT) and will be presented during the congress.