Hypotensive effects of lithospermic acid B isolated from the extract of Salviae miltiorrhizae Radix in the rat.
1. The in vivo and in vitro effects of lithospermic acid B (LSA-B), which was extracted from Salviae miltiorrhizae Radix, on vascular relaxation responses were examined in rats. 2. Intravenous injection of LSA-B (10-30 mg/kg) decreased the blood pressure in a dose-dependent manner. 3. In perfused mesenteric arterial bed precontracted with methoxamine (10(-5) M), LSA-B (10(-5) - 10(-3) M) produced a concentration-dependent relaxation. 4. Vasodilator response of the mesentery in response to LSA-B was reversed by 10(-4) M NG-monomethyl-L-arginine (L-NMMA). 5. The inhibition of vasodilation by L-NMMA was reversed by L-arginine (3 x 10(-4) M). 6. These results suggest that LSA-B-induced hypotensive effect may be due to the endothelium-dependent vasodilation of resistance artery such as mesenteric arterial bed.
Department of Pharmacology, School of Pharmaceutical Sciences, Hoshi University, Tokyo, Japan.
K
K
Kamata
M
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Noguchi
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M
Nagai
D000758:Anesthesia; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects; D007022:Hypotension / Q000139:chemically induced; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects / Q000502:physiology; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology; D010936:Plant Extracts / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D014664:Vasodilation / Q000187:drug effects
D004365:Drugs, Chinese Herbal; D010936:Plant Extracts; C061091:lithospermate B