Biomaterial Database

Norepinephrine modulates high voltage-activated calcium channels in freshly dissociated rat nucleus tractus solitarii neurons. 1995

H Ishibashi, and N Akaike

Department of Physiology, Kyushu University Faculty of Medicine, Fukuoka, Japan.

The effects of norepinephrine on the low- and high-voltage-activated calcium channels in the neurons acutely dissociated from the nucleus tractus solitarius of 2- to 3-week-old rats were investigated in the nystatin perforated patch recording configuration under voltage-clamp conditions. The norepinephrine had no effect on the low voltage-activated calcium channel but inhibited the high voltage-activated calcium channel in a concentration-, time- and voltage-dependent manner. The norepinephrine slowed the activation phase of the high voltage-activated calcium channel current and the maximum inhibition was 30% of the total current amplitude measured 10 ms after the current activation. The inhibitory effect was eliminated by applying larger depolarizing prepulses. The pretreatment with pertussis toxin completely blocked the norepinephrine effect on high-voltage activated calcium channels, suggesting the contribution of pertussis toxin-sensitive Gi/Go-proteins to the norepinephrine-induced inhibition. Yohimbine but not prazosin nor propranolol antagonized the norepinephrine-induced inhibition, suggesting the involvement of alpha 2-adrenoceptor in norepinephrine-induced inhibition of the high voltage-activated calcium channels. omega-Conotoxin-GVIA, omega-agatoxin-IVA, nicardipine and omega-conotoxin-MVIIC blocked the high voltage-activated calcium channel current by 26, 9, 36 and 11% of the total current respectively, suggesting the existence of N-, P-, L- and Q-type calcium channels in the nucleus tractus solitarii neurons. The current being insensitive to these calcium channel antagonists, termed R-type calcium channel current, also existed. This residual R-type calcium channel was completely blocked by adding 200 microM CD2+. The norepinephrine significantly inhibited N- and P-type calcium channels.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
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
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
D002121	Calcium Channel Blockers	A class of drugs that act by selective inhibition of calcium influx through cellular membranes.	Calcium Antagonists, Exogenous,Calcium Blockaders, Exogenous,Calcium Channel Antagonist,Calcium Channel Blocker,Calcium Channel Blocking Drug,Calcium Inhibitors, Exogenous,Channel Blockers, Calcium,Exogenous Calcium Blockader,Exogenous Calcium Inhibitor,Calcium Channel Antagonists,Calcium Channel Blocking Drugs,Exogenous Calcium Antagonists,Exogenous Calcium Blockaders,Exogenous Calcium Inhibitors,Antagonist, Calcium Channel,Antagonists, Calcium Channel,Antagonists, Exogenous Calcium,Blockader, Exogenous Calcium,Blocker, Calcium Channel,Blockers, Calcium Channel,Calcium Blockader, Exogenous,Calcium Inhibitor, Exogenous,Channel Antagonist, Calcium,Channel Blocker, Calcium,Inhibitor, Exogenous Calcium
D004594	Electrophysiology	The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
D006719	Homovanillic Acid	A 3-O-methyl ETHER of (3,4-dihydroxyphenyl)acetic acid.	3-Methoxy-4-Hydroxyphenylacetic Acid,4-Hydroxy-3-Methoxyphenylacetic Acid,3 Methoxy 4 Hydroxyphenylacetic Acid,4 Hydroxy 3 Methoxyphenylacetic Acid,Acid, 3-Methoxy-4-Hydroxyphenylacetic,Acid, 4-Hydroxy-3-Methoxyphenylacetic,Acid, Homovanillic
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
D001711	Biotransformation	The chemical alteration of an exogenous substance by or in a biological system. The alteration may inactivate the compound or it may result in the production of an active metabolite of an inactive parent compound. The alterations may be divided into METABOLIC DETOXICATION, PHASE I and METABOLIC DETOXICATION, PHASE II.
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor
D015220	Calcium Channels	Voltage-dependent cell membrane glycoproteins selectively permeable to calcium ions. They are categorized as L-, T-, N-, P-, Q-, and R-types based on the activation and inactivation kinetics, ion specificity, and sensitivity to drugs and toxins. The L- and T-types are present throughout the cardiovascular and central nervous systems and the N-, P-, Q-, & R-types are located in neuronal tissue.	Ion Channels, Calcium,Receptors, Calcium Channel Blocker,Voltage-Dependent Calcium Channel,Calcium Channel,Calcium Channel Antagonist Receptor,Calcium Channel Antagonist Receptors,Calcium Channel Blocker Receptor,Calcium Channel Blocker Receptors,Ion Channel, Calcium,Receptors, Calcium Channel Antagonist,VDCC,Voltage-Dependent Calcium Channels,Calcium Channel, Voltage-Dependent,Calcium Channels, Voltage-Dependent,Calcium Ion Channel,Calcium Ion Channels,Channel, Voltage-Dependent Calcium,Channels, Voltage-Dependent Calcium,Voltage Dependent Calcium Channel,Voltage Dependent Calcium Channels
D017208	Rats, Wistar	A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.	Wistar Rat,Rat, Wistar,Wistar Rats