Biomaterial Database

Action of nicotine on sympathetic nerve terminals. 1980

S M Kirpekar, and A G Garcia, and J C Prat

Interaction between 4-aminophrydine (4-AP) and nicotine on sympathetic nerve terminals was studied in the isolated cat spleen slices, labeled with [3H]norepinephrine ([3H]NE). Incubation of slices for 5 min at 37 degrees C in low (50 microM) and high (2 mM) concentrations of nicotine released 0.8 +/- 0.08 and 2.73 +/- 0.39% of tissue [3H]NE. Tetrodotoxin (TTX) blocked the response to low nicotine but not to high nicotine. Low nicotine did not release [3H]NE in the absence of calcium. Response to high nicotine which persisted in calcium-free solution was blocked by ethylene glycol bis(beta-aminoethyl ether)N,N'-tetra-acetic acid. 4-AP (1 mM) not only enhanced the response to low nicotine but it effectively antagonized the suppressant effects of TTX and calcium-free solution on release induced by low nitotine. Restoration of release by 4-AP from TTX-blocked preparations occurred in the absence of calcium in the perfusion medium, but lanthanum (1 mM) blocked it. Restoration of release from spleen slices incubated in calcium-free Krebs' solution by 4-AP was blocked by lanthanum and prolonged incubation in calcium-free ethylene glycol bis(beta-aminoethyl ether)N,N'-tetraaectic acid solution. It is concluded that at lower doses nicotine, by acting on nicotinic receptors, depolarizes the sympathetic nerve terminals to set off propagated action potentials which are responsible for NE release, and that 4-AP restores nicotine response in the presence of TTX or in the absence of calcium by mobilizing calcium both from extracellular and intracellular sources.

UI	MeSH Term	Description	Entries
D007811	Lanthanum	The prototypical element in the rare earth family of metals. It has the atomic symbol La, atomic number 57, and atomic weight 138.91. Lanthanide ion is used in experimental biology as a calcium antagonist; lanthanum oxide improves the optical properties of glass.
D009411	Nerve Endings	Branch-like terminations of NERVE FIBERS, sensory or motor NEURONS. Endings of sensory neurons are the beginnings of afferent pathway to the CENTRAL NERVOUS SYSTEM. Endings of motor neurons are the terminals of axons at the muscle cells. Nerve endings which release neurotransmitters are called PRESYNAPTIC TERMINALS.	Ending, Nerve,Endings, Nerve,Nerve Ending
D009538	Nicotine	Nicotine is highly toxic alkaloid. It is the prototypical agonist at nicotinic cholinergic receptors where it dramatically stimulates neurons and ultimately blocks synaptic transmission. Nicotine is also important medically because of its presence in tobacco smoke.	Nicotine Bitartrate,Nicotine Tartrate
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
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
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
D004347	Drug Interactions	The action of a drug that may affect the activity, metabolism, or toxicity of another drug.	Drug Interaction,Interaction, Drug,Interactions, Drug
D000631	Aminopyridines	Pyridines substituted in any position with an amino group. May be hydrogenated but must retain at least one double bond.	Aminopyridine
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
D013154	Spleen	An encapsulated lymphatic organ through which venous blood filters.