A difference in responsiveness of isolated hepatic artery, aorta, portal vein and vena cava of pig to flavin adenine dinucleotide including liver extract.
1. Tension of isolated hepatic artery, aorta, portal vein and vena cava of pigs was measured isometrically to study the mode of action of flavin adenine dinucleotide, including liver extract (FADLE). 2. FADLE showed concentration-dependent relaxation of norepinephrine contraction in the hepatic artery, but FADLE had little influence on the aorta, portal vein and vena cava contracted by norepinephrine (NE). 3. In Ca(2+)-free solution, FADLE-induced relaxation in both the hepatic artery and aorta contracted by NE was significantly reduced, and its reduction was greater in the hepatic artery than in the aorta. Furthermore, extracellular Ca2+ dependence of norepinephrine-induced contraction was much larger in the hepatic artery than in the aorta. 4. Results suggest that FADLE shows regional variations in vasorelaxation through the alteration of Ca2+ movement by the cell, and that this may reflect one of the mechanisms in its ability to increase blood flow in hepatic tissue.
Honda
H
H
Department of Pharmacology, Tokyo University of Pharmacy and Life Science, Japan.
Ikarashi
Y
Y
Yonebayashi
S
S
Shimizu
K
K
D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects; D002118:Calcium / Q000502:physiology; D005260:Female; D005182:Flavin-Adenine Dinucleotide / Q000494:pharmacology*; D006499:Hepatic Artery / Q000187:drug effects; D066298:In Vitro Techniques; D007537:Isometric Contraction / Q000187:drug effects; D008102:Liver Circulation / Q000187:drug effects*; D008110:Liver Extracts / Q000494:pharmacology*; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology; D011169:Portal Vein / Q000187:drug effects; D013552:Swine; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014683:Vena Cava, Superior / Q000187:drug effects
D008110:Liver Extracts; D014662:Vasoconstrictor Agents; D005182:Flavin-Adenine Dinucleotide; D002118:Calcium; D009638:Norepinephrine