Intact perivascular adipose tissue significantly reduced the contractile response to exogenous noradrenaline in normotensive rat mesenteric arteries (AUC 13.51 vs 23.81, p<0.01).
Does perivascular adipose tissue (PVAT) modulate sympatho-adrenergic contractions in arteries from normotensive and hypertensive rats?
PVAT has opposing effects on sympatho-adrenergic contractions depending on the artery type, and its impaired anticontractile influence in mesenteric arteries of hypertensive rats may contribute to increased adrenergic sensitivity.
Tasa de eventos absoluta: 13.51% vs 23.81%
valor p: p=<0.01
The inhibitory action of perivascular adipose tissue (PVAT) in modulation of arterial contraction has been recently recognized and contrasted with the prohypertensive effect of obesity in humans. In this study we demonstrated that PVAT might have opposing effect on sympatho-adrenergic contractions in different rat conduit arteries. In superior mesenteric artery isolated from normotensive Wistar-Kyoto rats (WKY), PVAT exhibited inhibitory influence on the contractions to exogenous noradrenaline as well as to endogenous noradrenaline released from arterial sympathetic nerves during transmural electrical stimulation or after application of tyramine. In contrast, the abdominal aorta with intact PVAT responded with larger contractions to transmural electrical stimulation and tyramine when compared to the aorta after removing PVAT; the responses to noradrenaline were similar in both. This indicates that PVAT may contain additional sources of endogenous noradrenaline which could be responsible for the main difference in the modulatory effect of PVAT on adrenergic contractions between abdominal aortas and superior mesenteric arteries. In spontaneously hypertensive rats (SHR), the anticontractile effect of PVAT in mesenteric arteries was reduced, and the removal of PVAT completely eliminated the difference in the dose-response curves to exogenous noradrenaline between SHR and WKY. These results suggest that in mesenteric artery isolated from SHR, the impaired anticontractile influence of PVAT might significantly contribute to its increased sensitivity to adrenergic stimuli.
Török et al. (Sun,) conducted a other in Hypertension (animal model) (n=20). Intact perivascular adipose tissue (PVAT) vs. Removed PVAT was evaluated on Dose-dependent contractile response to exogenous noradrenaline (Area Under Curve) in WKY mesenteric arteries (p=<0.01). Intact perivascular adipose tissue significantly reduced the contractile response to exogenous noradrenaline in normotensive rat mesenteric arteries (AUC 13.51 vs 23.81, p<0.01).
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