Biomaterial Database

Nitric oxide and arachidonic acid modulation of calcium currents in postganglionic neurones of avian cultured ciliary ganglia. 1993

G Khurana, and M R Bennett

Physiology Department, University of Sydney, N.S.W. Australia.

1. A study has been made of the modulation of high-voltage activated transient and sustained calcium currents in cultured neurones of avian ciliary ganglia by nitric oxide (NO) and arachidonic acid. 2. Sodium nitroprusside (100 microM) reduced the transient calcium current (ICa) on average by 31% and the sustained ICa by 32% during a test depolarization to +20 mV from a holding potential of -100 mV. This reduction was maintained for at least 30 min following a single application of sodium nitroprusside. 3. L-Arginine (270 microM) reduced the transient ICa on average by 28% and the sustained ICa by 22% and these effects were prevented by the presence of the NO-synthase competitive blocker NG-nitro-L-arginine methylester (L-NAME; 100 microM) in the bathing solution. 4. Arachidonic acid (50 microM) reduced the transient ICa on average by 28% and the sustained ICa by 33%. When added together, arachidonic acid (50 microM) and L-arginine (270 microM) produced the same effects as arachidonic acid alone. 5. Blocking the conversion of arachidonic acid to prostaglandins by addition of indomethacin (20 microM) to the bathing solution did not prevent the depression of either the transient or the sustained calcium current during application of arachidonic acid (50 microM). The effects of arachidonic acid were also not occluded by L-NAME (100 microM) when present in the bathing solution. 6. Inhibiting the biosynthesis of leukotrienes by applying L-663,536 (MK-886; 3 microM) to the bathing solution prevented the depression of both components of ICa during application of arachidonic acid (50 microM). 7. These results indicate that endogenous NO and arachidonic acid pathways are present in parasympathetic ciliary neurones, and that both act to depress high-voltage, gated, calcium channel activity.

UI	MeSH Term	Description	Entries
D007211	Indoles	Benzopyrroles with the nitrogen at the number one carbon adjacent to the benzyl portion, in contrast to ISOINDOLES which have the nitrogen away from the six-membered ring.
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
D009474	Neurons	The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.	Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
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
D009599	Nitroprusside	A powerful vasodilator used in emergencies to lower blood pressure or to improve cardiac function. It is also an indicator for free sulfhydryl groups in proteins.	Nitroferricyanide,Sodium Nitroprusside,Cyanonitrosylferrate,Ketostix,Naniprus,Nipride,Nipruton,Nitriate,Nitropress,Nitroprussiat Fides,Nitroprusside, Disodium Salt,Nitroprusside, Disodium Salt, Dihydrate,Disodium Salt Nitroprusside,Nitroprusside, Sodium
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D002642	Chick Embryo	The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.	Embryo, Chick,Chick Embryos,Embryos, Chick
D005726	Ganglia, Parasympathetic	Ganglia of the parasympathetic nervous system, including the ciliary, pterygopalatine, submandibular, and otic ganglia in the cranial region and intrinsic (terminal) ganglia associated with target organs in the thorax and abdomen.	Parasympathetic Ganglia,Ciliary Ganglion,Ganglion, Parasympathetic,Otic Ganglia,Pterygopalatine Ganglia,Submandibular Ganglia,Ciliary Ganglions,Ganglia, Otic,Ganglia, Pterygopalatine,Ganglia, Submandibular,Ganglias, Otic,Ganglias, Pterygopalatine,Ganglias, Submandibular,Ganglion, Ciliary,Ganglions, Ciliary,Otic Ganglias,Parasympathetic Ganglion,Pterygopalatine Ganglias,Submandibular Ganglias
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
D001120	Arginine	An essential amino acid that is physiologically active in the L-form.	Arginine Hydrochloride,Arginine, L-Isomer,DL-Arginine Acetate, Monohydrate,L-Arginine,Arginine, L Isomer,DL Arginine Acetate, Monohydrate,Hydrochloride, Arginine,L Arginine,L-Isomer Arginine,Monohydrate DL-Arginine Acetate