Chemo- and Mechano-Induced Reactions of Vascular Smooth Muscles in Rats with Chronic Insufficiency of Cerebral Dopamine: Effect of Co-Enzyme Q_(10)

摘要

In experiments on isolated preparations of segments of the aorta and portal vein, we demonstrated thatendothelium-dependent reactions of vascular smooth muscles (SMs) are suppressed in rats subjected todestruction of the nigro-striatal dopaminergic system in the left hemisphere (model of hemiparkinsonims).Under such conditions, the amplitude of relaxation of SMs of the wall of the thoracic aorta upon the actionof the endothelium-dependent vasodilator acetylcholine iodide was four times smaller, while the latencydemonstrated a 3.5-fold increase, as compared with the control. The amplitude of relaxation of vascularSMs after application of the endothelium-independent vasodilator sodium nitroprusside remained practicallyunchanged. In addition, preliminary stretching-induced increments of the amplitude of phasic contractions ofthe portal vein demonstrated a 2.5-fold decrease; this increment reached the maximum at smaller additionalloadings, while the rigidity of the vascular wall increased. In animals that obtained a preparation of coenzymeQ10 (10 mg/kg) with food during one month, contractile reactions of vascular SMs partly recovered. Theamplitude of endothelium-dependent relaxation of the aorta increased, the latency of this reaction shortened,stretching-induced increments of the amplitude of phasic contractions increased, and the rigidity of thevascular wall dropped. We conclude that the functional state of the endothelium is worsened, and the vascularreactivity is modified under conditions of chronic insufficiency of nigro-striatal dopamine. It seems probablethat oxidative stress is one of the main reasons for such changes. Coenzyme Q_(10) significantly normalizedabnormal vascular reactions (perhaps, due, to a considerable extent, to its antioxidant properties).