Biomaterial Database

Alpha-adrenoceptor subtypes and Ca2+ mobilization in the rabbit ear artery. 1983

S Manzini, and C A Maggi, and A Meli

The mobilization of cellular and extracellular Ca2+ pools by selective alpha 1-adrenoceptor (phenylephrine) and alpha 2-adrenoceptor (xylazine) agonists as well as noradrenaline was evaluated in rabbit ear artery. Noradrenaline and phenylephrine possess full intrinsic activity for both types of Ca2+ mobilization whereas xylazine up to 1 mM had only a limited contractile effect, being more effective in inducing extracellular Ca2+-dependent response. However, extracellular Ca2+ was mobilized by xylazine in a concentration 20 times higher than that required to stimulate pre-junctional alpha 2-adrenoceptors. Noradrenaline (5 microM) and xylazine (1 mM) induced cellular and extracellular Ca2+-dependent contractions which were prazosin-sensitive and yohimbine-resistant. Xylazine-induced contractile activity, particularly that dependent upon the extracellular Ca2+ pool, was markedly reduced by selective adrenergic denervation with 6-hydroxydopamine, but the actions of noradrenaline were unaffected. These results suggest that: (1) rabbit ear artery contain post-junctional alpha 1-adrenoceptor but not alpha 2-adrenoceptors; (2) stimulation of these alpha 1-adrenoceptors can account for the overall contractile activity of exogenously added noradrenaline and (3) stimulation of alpha 1-adrenoceptors results in mobilization of cellular as well as extracellular Ca2+ pools.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009131	Muscle, Smooth, Vascular	The nonstriated involuntary muscle tissue of blood vessels.	Vascular Smooth Muscle,Muscle, Vascular Smooth,Muscles, Vascular Smooth,Smooth Muscle, Vascular,Smooth Muscles, Vascular,Vascular Smooth Muscles
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
D010656	Phenylephrine	An alpha-1 adrenergic agonist used as a mydriatic, nasal decongestant, and cardiotonic agent.	(R)-3-Hydroxy-alpha-((methylamino)methyl)benzenemethanol,Metaoxedrin,Metasympatol,Mezaton,Neo-Synephrine,Neosynephrine,Phenylephrine Hydrochloride,Phenylephrine Tannate,Neo Synephrine,Tannate, Phenylephrine
D011224	Prazosin	A selective adrenergic alpha-1 antagonist used in the treatment of HEART FAILURE; HYPERTENSION; PHEOCHROMOCYTOMA; RAYNAUD DISEASE; PROSTATIC HYPERTROPHY; and URINARY RETENTION.	Furazosin,Minipress,Pratsiol,Prazosin HCL,Prazosin Hydrochloride,HCL, Prazosin,Hydrochloride, Prazosin
D011817	Rabbits	A burrowing plant-eating mammal with hind limbs that are longer than its fore limbs. It belongs to the family Leporidae of the order Lagomorpha, and in contrast to hares, possesses 22 instead of 24 pairs of chromosomes.	Belgian Hare,New Zealand Rabbit,New Zealand Rabbits,New Zealand White Rabbit,Rabbit,Rabbit, Domestic,Chinchilla Rabbits,NZW Rabbits,New Zealand White Rabbits,Oryctolagus cuniculus,Chinchilla Rabbit,Domestic Rabbit,Domestic Rabbits,Hare, Belgian,NZW Rabbit,Rabbit, Chinchilla,Rabbit, NZW,Rabbit, New Zealand,Rabbits, Chinchilla,Rabbits, Domestic,Rabbits, NZW,Rabbits, New Zealand,Zealand Rabbit, New,Zealand Rabbits, New,cuniculus, Oryctolagus
D011942	Receptors, Adrenergic, alpha	One of the two major pharmacological subdivisions of adrenergic receptors that were originally defined by the relative potencies of various adrenergic compounds. The alpha receptors were initially described as excitatory receptors that post-junctionally stimulate SMOOTH MUSCLE contraction. However, further analysis has revealed a more complex picture involving several alpha receptor subtypes and their involvement in feedback regulation.	Adrenergic alpha-Receptor,Adrenergic alpha-Receptors,Receptors, alpha-Adrenergic,alpha-Adrenergic Receptor,alpha-Adrenergic Receptors,Receptor, Adrenergic, alpha,Adrenergic alpha Receptor,Adrenergic alpha Receptors,Receptor, alpha-Adrenergic,Receptors, alpha Adrenergic,alpha Adrenergic Receptor,alpha Adrenergic Receptors,alpha-Receptor, Adrenergic,alpha-Receptors, Adrenergic
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
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
D006892	Hydroxydopamines	Dopamines with a hydroxy group substituted in one or more positions.	Hydroxydopamine