[Effect of lipid peroxidation products on vascular tonus]

A total of 126 experiments on the model of perfusion of isolated rabbit ear vessels were made to study the effect of primary (hydroperoxides - HP) and secondary products (SP) of phospholipid peroxidation (phosphatidyl ethanolamine - PEA), hydroperoxides of fatty acids (arachidonic acid - AA), as well as that of non-modified PEA and AA on the vascular tone. PEA in doses of 0.1 and 10 mumole produced a distinct vasodilator effect in 63 and 70% of cases, respectively. Unlike PEA, HP of PEA in doses of 0.01 and 0.1 mumole had a vasoconstrictive effect, which was manifested by a fall of the volumetric perfusion rate in 71 and 53% of cases, respectively. The SP of PEA also produced a vasoconstrictive action, but the effect was not dose-dependent. Study into the effects of AA and HP of AA revealed no distinct unidirectional action on the vascular tone. On the basis of the preliminary data the authors suggest that the effect of lipid peroxidation products on barrier properties of the sarcoplasmic reticulum membranes lies at the basis of their action on the vascular tone.