Effects of sub-chronic, in vivo administration of sigma-1 receptor ligands on platelet and aortic arachidonate cascade in streptozotocin-induced diabetic rats

Diabetes mellitus is a chronic metabolic disorder which induces endothelial dysfunction and platelet activation. Eicosanoids produced from arachidonic acid regulate cellular and vascular functions. Sigma-1 receptor expressed in platelets and endothelial cells can regulate intracellular signalization. Our aim was to examine the influence of sub-chronic, in vivo administered sigma-1 receptor ligands (2-(4-morpholino)ethyl-1-phenylcyclohexane-1-carboxylate, PRE-084; S-N-Benzyl-6,7-dimethoxy-1,2,3,4-tetrahydro-1-isoquinolineethanamine, a new compound (S)-L1; and N,N-dipropyl-2-[4-methoxy-3-(2-phenylethoxy)-phenyl]-ethylamine monohydrochloride, NE-100) on the ex vivo arachidonic acid metabolism of platelets and aorta in streptozotocin-induced diabetic rats. The serum level of sigma-1 receptor ligands was detected by liquid chromatography-mass spectrometry before the ex vivo analysis. Sigma-1 receptor and cyclooxygenase gene expression in platelets were determined by reverse transcription coupled quantitative polymerase chain reaction. The eicosanoid synthesis was examined by using of radiolabeled arachidonic acid substrate and enzyme-linked immunosorbent assay. In diabetic rats, the sub-chronic, in vivo administration of the sigma-1 receptor ligands modified the transcript levels of sigma-1 receptor and cyclooxygenase-1, the concentration of cyclooxygenase in platelets and the eicosanoid synthesis in both platelets and aorta. Sigma-1 receptor ligands, by changing platelet and blood vessel eicosanoid synthesis, may play a role in modulating diabetic complications.