Thoracic aorta rings from G6PD-Tg and WT mice were isolated from young and old groups. The artery was cleaned with saline (0.9% NaCl) prepared with sterile water treated with diethylpyrocarbonate (DEPC), under an illuminated dissecting loupe (Wild M3C, Leica Microsystems Inc. Buffalo Grove, IL USA) in cold light.
The rings were mounted in an organ bath system to measure the isometric tension and filled with 5 mL of modified Krebs-Henseleit physiological solution composed of (in mM): NaCl 115; KCl 4.6; MgCl2, 6H2O 1,2; CaCl2 2.5; NaHCO3 25; glucose 11.1 and EDTA disodium 0.01. This solution was equilibrated with a gaseous mixture (95% O2 and 5% CO2) that provides a pH of 7.3–7.4. The temperature of the solution was maintained at 37 °C. The optimal passive tension used was 1 g to perform the vascular studies. Vasodilation to acetylcholine (10−6 M) [51 (link)] was studied in aortic rings previously contracted with noradrenaline (3 × 10−7 M–3 × 10−6 M), in the absence and presence of L-arginine (10−3 M) [52 (link)] plus nor-NOHA acetate (10−5 M), an arginase inhibitor for 30 min [20 (link),53 (link)]. A high concentration of acetylcholine (10−6 M) is used to stimulate maximal NO release from endothelial cells. A decreased relaxation to this dose means maximal capacity of NO production.
The rings were mounted in an organ bath system to measure the isometric tension and filled with 5 mL of modified Krebs-Henseleit physiological solution composed of (in mM): NaCl 115; KCl 4.6; MgCl2, 6H2O 1,2; CaCl2 2.5; NaHCO3 25; glucose 11.1 and EDTA disodium 0.01. This solution was equilibrated with a gaseous mixture (95% O2 and 5% CO2) that provides a pH of 7.3–7.4. The temperature of the solution was maintained at 37 °C. The optimal passive tension used was 1 g to perform the vascular studies. Vasodilation to acetylcholine (10−6 M) [51 (link)] was studied in aortic rings previously contracted with noradrenaline (3 × 10−7 M–3 × 10−6 M), in the absence and presence of L-arginine (10−3 M) [52 (link)] plus nor-NOHA acetate (10−5 M), an arginase inhibitor for 30 min [20 (link),53 (link)]. A high concentration of acetylcholine (10−6 M) is used to stimulate maximal NO release from endothelial cells. A decreased relaxation to this dose means maximal capacity of NO production.
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