Biomaterial Database

Noradrenaline action on cat retinal ganglion cells is mediated by dopamine (D2) receptors. 1988

J Robbins, and K Wakakuwa, and H Ikeda

Vision Research Unit of Sherrington School, Rayne Institute, St. Thomas' Hospital, London, U.K.

Effects of iontophoretically applied noradrenaline, dopamine and their receptor antagonists on the retinal ganglion cells, were studied in optically intact eyes of barbiturate-anaesthetized cats. Noradrenaline inhibited visually evoked and spontaneous firing of all classes of retinal ganglion cells: the effect being greater on ON- than on OFF-cells and slightly more potent than dopamine on a given cell. All alpha- and beta-adrenoreceptor blockers tested tended to change spikes, but were generally ineffective in blocking the noradrenaline-induced inhibition, when not affecting spikes. The noradrenaline-induced inhibition was, however, effectively blocked by dopamine D2-receptor antagonists. The alpha- and beta-adrenoreceptor antagonists applied alone had no effect, suggesting the absence of endogenous noradrenergic antagonism, although alpha-type adrenergic antagonism was suggestive on a very small number of cells. These results suggest that: (1) noradrenaline action on cat retinal ganglion cells is mediated via dopamine D2-receptors; (2) noradrenaline is not generally released on them, except there may be physiologically active alpha-receptors on a few cells; and (3) many of the adrenoreceptor blockers affect membrane properties of the retinal ganglion cells, in a similar manner to local anaesthetics.

UI	MeSH Term	Description	Entries
D007478	Iontophoresis	Therapeutic introduction of ions of soluble salts into tissues by means of electric current. In medical literature it is commonly used to indicate the process of increasing the penetration of drugs into surface tissues by the application of electric current. It has nothing to do with ION EXCHANGE; AIR IONIZATION nor PHONOPHORESIS, none of which requires current.	Iontophoreses
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
D011954	Receptors, Dopamine	Cell-surface proteins that bind dopamine with high affinity and trigger intracellular changes influencing the behavior of cells.	Dopamine Receptors,Dopamine Receptor,Receptor, Dopamine
D012160	Retina	The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.	Ora Serrata
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D000200	Action Potentials	Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.	Spike Potentials,Nerve Impulses,Action Potential,Impulse, Nerve,Impulses, Nerve,Nerve Impulse,Potential, Action,Potential, Spike,Potentials, Action,Potentials, Spike,Spike Potential
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
D012165	Retinal Ganglion Cells	Neurons of the innermost layer of the retina, the internal plexiform layer. They are of variable sizes and shapes, and their axons project via the OPTIC NERVE to the brain. A small subset of these cells act as photoreceptors with projections to the SUPRACHIASMATIC NUCLEUS, the center for regulating CIRCADIAN RHYTHM.	Cell, Retinal Ganglion,Cells, Retinal Ganglion,Ganglion Cell, Retinal,Ganglion Cells, Retinal,Retinal Ganglion Cell
D013565	Sympatholytics	Drugs that inhibit the actions of the sympathetic nervous system by any mechanism. The most common of these are the ADRENERGIC ANTAGONISTS and drugs that deplete norepinephrine or reduce the release of transmitters from adrenergic postganglionic terminals (see ADRENERGIC AGENTS). Drugs that act in the central nervous system to reduce sympathetic activity (e.g., centrally acting alpha-2 adrenergic agonists, see ADRENERGIC ALPHA-AGONISTS) are included here.	Sympathetic-Blocking Agents,Sympatholytic,Sympatholytic Agent,Sympatholytic Drug,Sympatholytic Agents,Sympatholytic Drugs,Sympatholytic Effect,Sympatholytic Effects,Agent, Sympatholytic,Agents, Sympathetic-Blocking,Agents, Sympatholytic,Drug, Sympatholytic,Drugs, Sympatholytic,Effect, Sympatholytic,Effects, Sympatholytic,Sympathetic Blocking Agents
D017448	Receptors, Dopamine D2	A subfamily of G-PROTEIN-COUPLED RECEPTORS that bind the neurotransmitter DOPAMINE and modulate its effects. D2-class receptor genes contain INTRONS, and the receptors inhibit ADENYLYL CYCLASES.	Dopamine D2 Receptors,Dopamine-D2 Receptor,D2 Receptors, Dopamine,Dopamine D2 Receptor,Receptor, Dopamine-D2