Effects of Vitamin K-1 and Menaquinone-7 on Vascular Function and Blood Pressure in Warfarin-Induced Calcification-Model in Rats

Given that vascular calcification is inversely correlated with the clinical intake of menaquinone, a rat model of warfarin-induced calcification may be useful for testing menaquinone and vitamin K-1 potential effects on vascular function. The aim of the present study was to investigate effects of vitamin K-1 and menaquinone-7 treatments on blood pressure and vascular function in warfarininduced vascular calcification model during five-week intervention in normotensive Wistar-Kyoto rats. Blood pressure was measured weekly, and at the end of the intervention in vitro vascular reactivity measurements were done. Alizarin Red S and von Kossa stainings were used to record possible calcification of aortic sections. Routine clinical chemistry was done from serum and urine samples. Vascular calcification was seen only in a few warfarin-treated animals in histological staining. Warfarin-treatment did not change significantly blood pressure of the rats. Warfarintreatment increased slightly the endothelium-dependent relaxation of aorta after the L-type calcium channels were blocked. Also the vascular relaxation improved after NOS inhibition in the aorta of the healthy controls and menaquinone-7 treated animals, indicating that the relaxation in those groups was not totally dependent on NO. Clinical chemistry from serum showed some differences in urea, creatinine as well as lipid and glucose metabolism between the healthy controls and warfarin-treated rats.