The effects of 15 lignan compounds, which were extracted from schisandra fruits, on the contractions of an isolated mesenteric artery of dog induced by prostaglandin F_2α (PGF_2α), CaCl₂ or norepinephrine (NE) were examined. As a result, all lignan compounds used showed inhibitory effects on the contractions of mesenteric artery induced by PGF_2α and CaCl₂. However, 6 compounds such as gomisin J (GJ) also showed inhibitory effects on NE-induced contraction. We further examined the actions of GJ with much better activity. Since GJ is not soluble in water, we synthesized GJ-Na (GJN) and further used throughout the experiments. In the isolated mesenteric artery of dog, GJN showed inhibitory effects on the NE-induced contraction (ID₅₀=131.8±0.11×10^-6 M), and relaxant effects on PGF_2α-induced contractions (ED₅₀=9.72±0.36×10^-6 M), and also showed inhibitory effects on CaCl₂-induced contraction (ID₅₀=6.96±0.16×10^-6 M). Furthermore, GJN showed relaxant effects and an increase in coronary flow on the isolated trachea, ileum, taenia coli and heart in guinea-pigs, GJ (10^-4 and 3×10^-4 g, i.a.) produced an increase in coronary artery blood flow in anesthetized dog, although its effect was slightly weaker than that in diltiazem, a well known calcium antagonist. As mentioned above, it was confirmed that lignan compounds extracted from schisandra fruits had Ca antagonistic actions in varying degrees, and that GJN had a dilating effect on the coronary artery.

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