Biomaterial Database

Nitric oxide modulates hepatic vascular tone in normal rat liver. 1994

M K Mittal, and T K Gupta, and F Y Lee, and C C Sieber, and R J Groszmann

Hepatic Hemodynamic Laboratory, Veterans Affairs Medical Center, West Haven 06516.

This study investigated whether nitric oxide (NO) plays a role in the intrahepatic portal circulation in normal rat livers perfused in situ. N omega-nitro-L-arginine (NNA), a specific NO biosynthesis inhibitor, significantly increased baseline portal pressure compared with controls (P < 0.05). Concentration-effect curves to norepinephrine (NE) were performed. Perfusate flow was maintained as constant, and perfusion pressure was continuously measured. NNA markedly enhanced the responsiveness to NE. This effect was abolished by the addition of L-arginine, a specific NO substrate. Presence of indomethacin did not alter the response to NE. The response to NE in the presence of indomethacin and NNA was significantly more than the response to NE in the presence of NNA alone. In vivo, intraportal infusion of NNA significantly enhanced the portal pressure compared with vehicle. This study demonstrates that NO contributes to the basal vascular tone and attenuates the response to NE in intrahepatic portal vascular bed of normal rats. These results support a functional role of NO in the regulation of the intrahepatic portal circulation in normal rats. This study also suggests a synergistic, albeit limited, role of prostacyclin in the intrahepatic circulation.

UI	MeSH Term	Description	Entries
D007213	Indomethacin	A non-steroidal anti-inflammatory agent (NSAID) that inhibits CYCLOOXYGENASE, which is necessary for the formation of PROSTAGLANDINS and other AUTACOIDS. It also inhibits the motility of POLYMORPHONUCLEAR LEUKOCYTES.	Amuno,Indocid,Indocin,Indomet 140,Indometacin,Indomethacin Hydrochloride,Metindol,Osmosin
D007262	Infusions, Intravenous	The long-term (minutes to hours) administration of a fluid into the vein through venipuncture, either by letting the fluid flow by gravity or by pumping it.	Drip Infusions,Intravenous Drip,Intravenous Infusions,Drip Infusion,Drip, Intravenous,Infusion, Drip,Infusion, Intravenous,Infusions, Drip,Intravenous Infusion
D008102	Liver Circulation	The circulation of BLOOD through the LIVER.	Hepatic Circulation,Circulation, Liver,Circulation, Hepatic
D008297	Male		Males
D009569	Nitric Oxide	A free radical gas produced endogenously by a variety of mammalian cells, synthesized from ARGININE by NITRIC OXIDE SYNTHASE. Nitric oxide is one of the ENDOTHELIUM-DEPENDENT RELAXING FACTORS released by the vascular endothelium and mediates VASODILATION. It also inhibits platelet aggregation, induces disaggregation of aggregated platelets, and inhibits platelet adhesion to the vascular endothelium. Nitric oxide activates cytosolic GUANYLATE CYCLASE and thus elevates intracellular levels of CYCLIC GMP.	Endogenous Nitrate Vasodilator,Mononitrogen Monoxide,Nitric Oxide, Endothelium-Derived,Nitrogen Monoxide,Endothelium-Derived Nitric Oxide,Monoxide, Mononitrogen,Monoxide, Nitrogen,Nitrate Vasodilator, Endogenous,Nitric Oxide, Endothelium Derived,Oxide, Nitric,Vasodilator, Endogenous Nitrate
D009638	Norepinephrine	Precursor of epinephrine that is secreted by the ADRENAL MEDULLA and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers, and of the diffuse projection system in the brain that arises from the LOCUS CERULEUS. It is also found in plants and is used pharmacologically as a sympathomimetic.	Levarterenol,Levonorepinephrine,Noradrenaline,Arterenol,Levonor,Levophed,Levophed Bitartrate,Noradrenaline Bitartrate,Noradrénaline tartrate renaudin,Norepinephrin d-Tartrate (1:1),Norepinephrine Bitartrate,Norepinephrine Hydrochloride,Norepinephrine Hydrochloride, (+)-Isomer,Norepinephrine Hydrochloride, (+,-)-Isomer,Norepinephrine d-Tartrate (1:1),Norepinephrine l-Tartrate (1:1),Norepinephrine l-Tartrate (1:1), (+,-)-Isomer,Norepinephrine l-Tartrate (1:1), Monohydrate,Norepinephrine l-Tartrate (1:1), Monohydrate, (+)-Isomer,Norepinephrine l-Tartrate (1:2),Norepinephrine l-Tartrate, (+)-Isomer,Norepinephrine, (+)-Isomer,Norepinephrine, (+,-)-Isomer
D010477	Perfusion	Treatment process involving the injection of fluid into an organ or tissue.	Perfusions
D011169	Portal Vein	A short thick vein formed by union of the superior mesenteric vein and the splenic vein.	Portal Veins,Vein, Portal,Veins, Portal
D011312	Pressure	A type of stress exerted uniformly in all directions. Its measure is the force exerted per unit area. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Pressures
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia