Organic Cation Transporter 3 Contributes to Norepinephrine Uptake into Perivascular Adipose Tissue.

Organic Cation Transporter 3 Contributes to Norepinephrine Uptake into Perivascular Adipose Tissue. Am J Physiol Heart Circ Physiol. 2015 Oct 2;:ajpheart.00308.2015 Authors: Ayala-Lopez N, Jackson WF, Burnett R, Wilson JN, Thompson JM, Watts SW Abstract Perivascular adipose tissue (PVAT) reduces vasoconstriction to norepinephrine (NE). A potential mechanism by which PVAT could function to reduce vascular contraction is by decreasing the amount of NE to which the vessel is exposed. PVATs from male Sprague-Dawley rats were used to test the hypothesis that PVAT has a NE uptake mechanism. NE was detected by HPLC in mesenteric PVAT and isolated adipocytes. Uptake of NE (10 µM) was reduced by the norepinephrine transporter (NET) inhibitor nisoxetine (1 µM; 73.68±7.62%; all values reported as percent of vehicle), the 5-hydroxytryptamine transporter (SERT) inhibitor citalopram (100 nM) with the organic cation transporter 3 (OCT3) inhibitor corticosterone (100 µM; 56.18±5.21%), and the NET inhibitor desipramine (10 µM) with corticosterone (100 µM; 61.18±6.82%). Confocal imaging of PVAT stained with 4-[4-(dimethylamino)-styrl]-N-methylpyridium iodide (ASP(+)), a fluorescent substrate of cationic transporters, detected ASP(+) uptake into adipocytes. ASP(+) (2 µM) uptake was reduced by citalopram (100 nM; 66.68±6.43%), corticosterone (100 µM; 43.49±10.17%), nisoxetine (100 nM; 84.12±4.24%), citalopram with corticosterone (100 nM and...
Source: American Journal of Physiology. Heart and Circulatory Physiology - Category: Physiology Authors: Tags: Am J Physiol Heart Circ Physiol Source Type: research