BIOMAT Database Logo BIOMAT Database Logo

Demonstration in human atrial preparations of alpha-adrenoceptors mediating positive inotropic effects. 1978

H J Schümann, and J Wagner, and A Knorr, and J C Reidemeister, and V Sadony, and G Schramm

In isolated, electrically driven right auricular strips of the human heart the inotropic effect of phenylephrine was studied. 1. First, the influence of the driving rate on the tension developed (i.e., the frequency-force relationship) was determined by stimulation of the preparations at 0.1, 0.5, 1, 2 and 3 HZ. The force of contraction was lowest at a stimulation rate of 0.1 HZ (36.9 g/g dry weight). The maximally developed force of contraction observed at frequencies of 0.5, 1 and 2 HZ amounted to about 200 g/g dry weight. The values did not significantly differ from each other. 2. The negative log of the EC50 (-log EC50) for the positive inotropic effect of phenylephrine determined at a frequency of 0.5 and 1.0 HZ amounted to 5.28 +/- 0.08 and 5.34 +/- 0.11, respectively. The alpha-adrenolytic drug phentolamine (3 x 10(-6) M) diminished significantly the -log EC50 to 5.01 +/- 0.04 and 4.89 +/- 0.10, respectively. 3. At a frequency of 1 HZ a shift of the concentration-response curve to the right was observed after treatment with the beta-adrenolytic drug pindolol (3 x 10(-8) M); the -log EC50 of phenylephrine decreased significantly to 4.08 +/- 0.07. 4. From these results it is concluded that alpha-adrenoceptors are present in human atria; they mediate positive inotropic effects and are stimulated by phenylephrine.

UI MeSH Term Description Entries
D009200 Myocardial Contraction Contractile activity of the MYOCARDIUM. Heart Contractility,Inotropism, Cardiac,Cardiac Inotropism,Cardiac Inotropisms,Contractilities, Heart,Contractility, Heart,Contraction, Myocardial,Contractions, Myocardial,Heart Contractilities,Inotropisms, Cardiac,Myocardial Contractions
D010646 Phentolamine A nonselective alpha-adrenergic antagonist. It is used in the treatment of hypertension and hypertensive emergencies, pheochromocytoma, vasospasm of RAYNAUD DISEASE and frostbite, clonidine withdrawal syndrome, impotence, and peripheral vascular disease. Fentolamin,Phentolamine Mesilate,Phentolamine Mesylate,Phentolamine Methanesulfonate,Phentolamine Mono-hydrochloride,Regitine,Regityn,Rogitine,Z-Max,Mesilate, Phentolamine,Mesylate, Phentolamine,Methanesulfonate, Phentolamine,Mono-hydrochloride, Phentolamine,Phentolamine Mono hydrochloride
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
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
D011941 Receptors, Adrenergic Cell-surface proteins that bind epinephrine and/or norepinephrine with high affinity and trigger intracellular changes. The two major classes of adrenergic receptors, alpha and beta, were originally discriminated based on their cellular actions but now are distinguished by their relative affinity for characteristic synthetic ligands. Adrenergic receptors may also be classified according to the subtypes of G-proteins with which they bind; this scheme does not respect the alpha-beta distinction. Adrenergic Receptors,Adrenoceptor,Adrenoceptors,Norepinephrine Receptor,Receptors, Epinephrine,Receptors, Norepinephrine,Adrenergic Receptor,Epinephrine Receptors,Norepinephrine Receptors,Receptor, Adrenergic,Receptor, Norepinephrine
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
D006321 Heart The hollow, muscular organ that maintains the circulation of the blood. Hearts
D006801 Humans Members of the species Homo sapiens. Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D013268 Stimulation, Chemical The increase in a measurable parameter of a PHYSIOLOGICAL PROCESS, including cellular, microbial, and plant; immunological, cardiovascular, respiratory, reproductive, urinary, digestive, neural, musculoskeletal, ocular, and skin physiological processes; or METABOLIC PROCESS, including enzymatic and other pharmacological processes, by a drug or other chemical. Chemical Stimulation,Chemical Stimulations,Stimulations, Chemical
D066298 In Vitro Techniques Methods to study reactions or processes taking place in an artificial environment outside the living organism. In Vitro Test,In Vitro Testing,In Vitro Tests,In Vitro as Topic,In Vitro,In Vitro Technique,In Vitro Testings,Technique, In Vitro,Techniques, In Vitro,Test, In Vitro,Testing, In Vitro,Testings, In Vitro,Tests, In Vitro,Vitro Testing, In

Related Publications

H J Schümann, and J Wagner, and A Knorr, and J C Reidemeister, and V Sadony, and G Schramm
Demonstration in Tupaia papillary muscle preparations of alpha-adrenoceptors mediating positive inotropic effects: comparison with guinea-pigs.
October 1989, British journal of pharmacology,
H J Schümann, and J Wagner, and A Knorr, and J C Reidemeister, and V Sadony, and G Schramm
Further characterization of the myocardial alpha-adrenoceptors mediating positive inotropic effects in the rabbit myocardium.
August 1988, European journal of pharmacology,
H J Schümann, and J Wagner, and A Knorr, and J C Reidemeister, and V Sadony, and G Schramm
Alpha-adrenoceptors and alpha-adrenoceptor-mediated positive inotropic effects in failing human myocardium.
September 1988, Journal of cardiovascular pharmacology,
H J Schümann, and J Wagner, and A Knorr, and J C Reidemeister, and V Sadony, and G Schramm
Positive inotropic effects mediated by alpha 1 adrenoceptors in intact human subjects.
October 1989, Journal of cardiovascular pharmacology,
H J Schümann, and J Wagner, and A Knorr, and J C Reidemeister, and V Sadony, and G Schramm
Positive inotropic effects of papaverine and aminophylline on isolated human atrial preparations.
September 1972, Research communications in chemical pathology and pharmacology,
H J Schümann, and J Wagner, and A Knorr, and J C Reidemeister, and V Sadony, and G Schramm
alpha-Adrenoceptors mediating positive inotropic effects on the ventricular myocardium: some aspects of structure-activity relationship of sympathomimetic amines.
April 1976, Japanese journal of pharmacology,
H J Schümann, and J Wagner, and A Knorr, and J C Reidemeister, and V Sadony, and G Schramm
Are alpha-adrenoceptors involved in positive inotropic effects of phenylephrine in chick ventricles?
September 1987, Japanese journal of pharmacology,
H J Schümann, and J Wagner, and A Knorr, and J C Reidemeister, and V Sadony, and G Schramm
Preponderance of beta- over alpha-adrenoceptors in mediating the positive inotropic effect of phenylephrine in the ferret ventricular myocardium.
March 1989, Naunyn-Schmiedeberg's archives of pharmacology,
H J Schümann, and J Wagner, and A Knorr, and J C Reidemeister, and V Sadony, and G Schramm
alpha-Adrenoceptors mediating the positive inotropic effect of phenylephrine in the right ventricular muscle of the monkey (Macaca fuscata).
March 1982, Naunyn-Schmiedeberg's archives of pharmacology,
H J Schümann, and J Wagner, and A Knorr, and J C Reidemeister, and V Sadony, and G Schramm
Characterization of adrenoceptors mediating positive inotropic responses in the ventricular myocardium of the dog.
September 1978, British journal of pharmacology,
Copied contents to your clipboard!