ABSTRACT
OBJECTIVE@#To determine the relationship between the nitroglycerin tolerance and the stimulation of radical oxygen species (ROS) production, and the therapeutical effect of 3,4,5,6-tetrahydroxyxanthone.@*METHODS@#Vasodilator responses to nitroglycerin were examined in the isolated thoracic aorta. The contents of ROS,and cGMP were determined in the cultured human umbilical vein endothelial cells.@*RESULTS@#3,4,5,6-tetrahydroxyxanthone could significantly reduce the inhibition of relaxation by nitroglycerin. 3,4,5,6-tetrahydroxyxanthone could significantly inhibit the ROS increase and increase the cGMP level.@*CONCLUSION@#Nitroglycerin tolerance is associated with the stimulation of ROS production,and the reversal of nitroglycerin tolerance with 3,4,5,6-tetrahydroxyxanthone is related to the reduction of ROS.
Subject(s)
Animals , Humans , Male , Rats , Antioxidants , Pharmacology , Aorta, Thoracic , Cell Biology , Cells, Cultured , Drug Tolerance , Endothelium, Vascular , Cell Biology , Nitroglycerin , Pharmacology , Oxidative Stress , Rats, Sprague-Dawley , Reactive Oxygen Species , Metabolism , Umbilical Veins , Cell Biology , Xanthones , PharmacologyABSTRACT
OBJECTIVE@#To investigate the effect of reinioside C (RC) on the expression of lectin-like oxidized low density lipoprotein receptor (LOX)-1 mRNA and LOX-1 protein induced by oxidized low density lipoprotein (ox-LDL) in cultured human umbilical vein endothelial cells (HUVEC).@*METHODS@#HUVECs were cultured with ox-LDL (50 mg/L) for 24 h in the absence or presence of RC (1, 3, and 10 micromol/L). The expressions of LOX-1 mRNA and LOX-1 protein were examined by RT-PCR and Western-blot.@*RESULTS@#Incubation with ox-LDL (50 mg/L) significantly raised the expression of LOX-1 mRNA and LOX-1 protein,which was concentration-dependent.@*CONCLUSION@#RC can inhibit the increased expression of LOX-1 mRNA and LOX-1 protein induced by ox-LDL in HUVECs.