Endomorphins restored the endothelium-dependent relaxation of the rabbit aorta rings exposed to high D-glucose condition via NO-cGMP pathway.

Rings of rabbit aorta that were both incubated in a high concentration of D-glucose and contracted submaximally by phenylephrine showed significantly decreased endothelium-dependent relaxations induced by acetylcholine. The cGMP production of aorta rings was also reduced. Treatment with endomorphins (1-1000 nmol/L) restored acetylcholine-induced relaxations of aorta rings incubated in high glucose concentrations and increased the cGMP synthesis. Moreover, this effect of endomorphins on endothelium was antagonized by naloxone, and the increase in the production of cGMP was also blocked.