Biomaterial Database

The in vitro pharmacology of xamoterol (ICI 118,587). 1985

E Malta, and M A Mian, and C Raper

The effect of xamoterol and (-)-isoprenaline have been compared for their activity at beta-adrenoceptor sites in a number of in vitro cardiac and smooth muscle preparations. Xamoterol produced weak positive chronotropic effects in guinea-pig, rat and cat atria (intrinsic activity less than 0.55, (-)-isoprenaline = 1). Positive inotropic effects were obtained in driven left atria of the cat but were absent in guinea-pig left atrial and right ventricular strip preparations. Agonistic effects were due to beta 1-adrenoceptor stimulation. Xamoterol was without beta-adrenoceptor-mediated inhibitory effects in guinea-pig ileal, tracheal and uterine preparations and in the rat vas deferens and oestrogen-primed uterus. Weak beta 2-adrenoceptor-mediated relaxation was obtained in progesterone-primed rat uteri. Xamoterol produced non-specific inhibitory effects in guinea-pig ileal and tracheal preparations. Xamoterol acted as a competitive antagonist at beta 1-(pA2 range = 7.4 to 7.8) and beta 2-adrenoceptors (pA2 range 5.2 to 6.2) and displaced [125I]-iodocyanopindolol from guinea-pig left atrial (pKD = 7.25) and uterine (pKD 5.24) membrane preparations. It is concluded that xamoterol displays a selective affinity for beta 1-adrenoceptors. Although its partial agonistic actions are more evident at beta 1-adrenoceptor sites, like prenalterol, xamoterol displays a degree of tissue rather than receptor-dependent selectivity.

UI	MeSH Term	Description	Entries
D007457	Iodine Radioisotopes	Unstable isotopes of iodine that decay or disintegrate emitting radiation. I atoms with atomic weights 117-139, except I 127, are radioactive iodine isotopes.	Radioisotopes, Iodine
D007545	Isoproterenol	Isopropyl analog of EPINEPHRINE; beta-sympathomimetic that acts on the heart, bronchi, skeletal muscle, alimentary tract, etc. It is used mainly as bronchodilator and heart stimulant.	Isoprenaline,Isopropylarterenol,4-(1-Hydroxy-2-((1-methylethyl)amino)ethyl)-1,2-benzenediol,Euspiran,Isadrin,Isadrine,Isopropyl Noradrenaline,Isopropylnoradrenaline,Isopropylnorepinephrine,Isoproterenol Hydrochloride,Isoproterenol Sulfate,Isuprel,Izadrin,Norisodrine,Novodrin,Hydrochloride, Isoproterenol,Noradrenaline, Isopropyl,Sulfate, Isoproterenol
D008297	Male		Males
D009130	Muscle, Smooth	Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)	Muscle, Involuntary,Smooth Muscle,Involuntary Muscle,Involuntary Muscles,Muscles, Involuntary,Muscles, Smooth,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
D010869	Pindolol	A moderately lipophilic beta blocker (ADRENERGIC BETA-ANTAGONISTS). It is non-cardioselective and has intrinsic sympathomimetic actions, but little membrane-stabilizing activity. (From Martindale, The Extra Pharmocopoeia, 30th ed, p638)	Prindolol,LB-46,Visken,LB 46,LB46
D011412	Propanolamines	AMINO ALCOHOLS containing the propanolamine (NH2CH2CHOHCH2) group and its derivatives.	Aminopropanols
D012032	Refractory Period, Electrophysiological	The period of time following the triggering of an ACTION POTENTIAL when the CELL MEMBRANE has changed to an unexcitable state and is gradually restored to the resting (excitable) state. During the absolute refractory period no other stimulus can trigger a response. This is followed by the relative refractory period during which the cell gradually becomes more excitable and the stronger impulse that is required to illicit a response gradually lessens to that required during the resting state.	Period, Neurologic Refractory,Periods, Neurologic Refractory,Refractory Period, Neurologic,Tetanic Fade,Vvedenskii Inhibition,Wedensky Inhibition,Inhibition, Vvedenskii,Inhibition, Wedensky,Neurologic Refractory Period,Neurologic Refractory Periods,Neuromuscular Fade,Neuromuscular Transmission Fade,Refractory Period, Neurological,Refractory Periods, Neurologic,Electrophysiological Refractory Period,Electrophysiological Refractory Periods,Fade, Neuromuscular,Fade, Neuromuscular Transmission,Fade, Tetanic,Neurological Refractory Period,Neurological Refractory Periods,Refractory Periods, Electrophysiological,Refractory Periods, Neurological,Transmission Fade, Neuromuscular
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
D005260	Female		Females