Vplyv perivaskulárneho tukového tkaniva na reaktivitu veľkých artérií u potkanov s rôznou predispozíciou k hypertenzii.

In this study, the effect of perivascular adipose tissue (PVAT) on sympathoadrenergic contractions of conduit arteries was studied in rats with normal and increased blood pressure. The superior mesenteric artery and abdominal aorta were excised from 12-week-old rats of the Wistar-Kyoto (WKY), normotensive strain, spontaneously hypertensive rats (SHR), and borderline hypertensive rats (BHR) derived from cross-breeding SHR females with WKY males and paired ring preparations with PVAT intact or removed were prepared from these arteries. In normotensive as well as in hypertensive rats, PVAT exhibited an inhibitory effect on contractile responses of mesenteric arteries to exogenous noradrealine. In the mesenteric arteries of WKY, the anticontractile effect of PVAT was observed also during neurogenic contractions evoked by electrical stimulation of perivascular sympathetic nerves; however, it was not significant in BHR and SHR. In the abdominal aorta of any group of rats, PVAT did not significantly influence the contractions to exogenous noradrenaline. The neurogenic contractions of the abdominal aorta from WKY and BHR were significantly increased in the presence of PVAT, possibly due to the higher density of sympathetic nerve endings in the PVAT of this artery. In conclusion, the inhibitory effect of PVAT on sympathoadrenergic contractions is hladdependent on the density and distribution of sympathetic nerves in the arterial wall, as the sympathetic innervation might also be present in PVAT and it could influence the vasomodulatory action of PVAT. Furthermore, the weaker anticontractile effect of PVAT in the mesenteric arteries from SHR might contribute to their enhanced sensitivity to adrenergic stimuli. [ABSTRACT FROM AUTHOR]