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Luminescence color change of poly-(2,5-dioctyl para-phenyleneethynylene) through variations of excitation intensity was reported. The two ways of changing the emission color are possible and para-pheyleneethynylene is expected to be useful in color tuning applications.

Perivascular adipose tissue (PVAT) reduces vasoconstriction to norepinephrine (NE). A 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) in mesenteric PVAT was reduced by the NE transporter (NET) inhibitor nisoxetine (1 μM, 73.68 ± 7.62%, all values reported as percentages 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%). Aortic PVAT NE uptake was reduced by corticosterone (100 μM, 53.01 ± 10.96%). Confocal imaging of mesenteric PVAT stained with 4-[4-(dimethylamino)-styrl]-N-methylpyridinium 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 100 μM, respectively, 35.75 ± 4.21%), and desipramine with corticosterone (10 and 100 μM, respectively, 50.47 ± 5.78%). NET protein was not detected in mesenteric PVAT adipocytes. Expression of Slc22a3 (OCT3 gene) mRNA and protein in PVAT adipocytes was detected by RT-PCR and immunocytochemistry, respectively. These end points support the presence of a transporter-mediated NE uptake system within PVAT with a potential mediator being OCT3. [ABSTRACT FROM AUTHOR]

Perivascular adipose tissue (PVAT) is under recognized for its importance in blood pressure regulation. Visceral adipocytes reportedly contain catecholamines. Adipocytes in PVAT are directly adjacent to the blood vessels they surround and therefore the production, release and/or reuptake of catecholamines may significantly affect vascular tone. We hypothesize that an adrenergic system is present in PVAT. Glyoxylic acid staining revealed the presence of catecholamines in the cytosol of mesenteric PVAT adipocytes. Dopamine (DA), norepinephrine (NE) and epinephrine were quantified by HPLC in rat aortic PVAT, brown fat, mesenteric PVAT and retroperitoneal fat with NE being the most abundant at concentrations of 731.9, 815.0, 668.7 and 73.2 ng/g from each tissue, respectively. Two key enzymes in catecholamine synthesis; tyrosine hydroxylase and dopamine β-hydroxylase, were located to PVAT adipocytes by immunohistochemistry. The norepinephrine transporter (NET) was detected on mesenteric PVAT adipocytes by confocal microscopy using ASP+ (2μM), a fluorescent NET substrate. Uptake of ASP+ was blocked by the NET specific inhibitor nisoxetine (10μM) (see figure). These data show that PVAT contains all of the elements of an adrenergic system and may contribute to vascular and adipose function in health and disease. [ABSTRACT FROM AUTHOR]