Effects of salsolinol on cultivated endothelial cells.

In view of neurotoxic properties of tetrahydroisoquinolines (TIQ's) there are open questions also in regard to the disturbance of the blood-brain barrier. Because endothelial cells are an important element of this barrier the present study was designed to assess the influence of salsolinol (a TIQ formed by condensation of dopamine and acetaldehyde) on cultivated endothelial cells by physiological, biochemical and morphological investigations. For the investigations we used aortic endothelial cells because of a variety of similarities in physiology and biochemistry to brain capillary endothelial cells. Cytotoxic effects estimated by cell counting after 72 h treatment with salsolinol (IC50 = 38 mumol/l) were possibly caused by mitochondrial damages. Already after 2 h severe ultrastructural alterations of many mitochondria could be observed. The respiration activity of the cells was always inhibited after treatment with salsolinol for some hours. The damage of the mitochondria by salsolinol was not connected with inhibition of the activity of succinate dehydrogenase and cytochrome c + c1. Nevertheless the damages of mitochondrial integrity support the hypothesis that the neurotoxic effect of salsolinol is primarily caused by damaging the endothelial cells associated with a disturbance of blood-brain barrier.