Implications of altered inotropic effects of phenylephrine in pressure-overloaded cat ventricular muscle. 1984

M S Gaide, and J R Wiggins, and W S Fitterman, and J S Cameron, and R J Myerburg, and A L Bassett

The positive inotropic action of phenylephrine in cardiac muscle is mediated by alpha- and beta-adrenoceptors. Data suggest the responsiveness of myocardium to inotropic agents is altered in cardiac disease. We evaluated the actions of phenylephrine on isometric contraction and K+-induced contracture in isolated cat right ventricular muscle from normal hearts and hearts with partial pulmonary artery ligation-induced pressure overload of 5-11 days in duration. Peak contractile force (Po) and rate of force development (dP/dt) were lower (p less than or equal to 0.005) in pressure-overloaded (0.59 +/- 0.2 g/mm2 and 4.6 +/- 1.7 g/s/mm2, respectively) than in normal (1.33 +/- 0.2 g/mm2 and 10.5 +/- 1.6 g/s/mm2, respectively) muscle. Phenylephrine (10(-6), 5 X 10(-6), and 10(-5) M) significantly (p less than or equal to 0.01) increased Po and dP/dt in normal but not in pressure-overloaded muscle. Phenylephrine (5 X 10(-6) M) reduced peak K+-induced contracture force (Pc) similarly in normal (-30 +/- 8%) and pressure-overloaded (-36 +/- 11%) muscles. beta-Adrenergic blockade (nadolol, 10(-4) M) reduced, but did not abolish, the "relaxant" action of the drug on Pc in both muscle groups. The lack of a positive inotropic effect of phenylephrine in pressure-overloaded muscle suggests a derangement in both alpha- and beta-adrenoceptor function in this model of cardiac disease.

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
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
D011188 Potassium An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
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
D001794 Blood Pressure PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS. Systolic Pressure,Diastolic Pressure,Pulse Pressure,Pressure, Blood,Pressure, Diastolic,Pressure, Pulse,Pressure, Systolic,Pressures, Systolic
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
D004305 Dose-Response Relationship, Drug The relationship between the dose of an administered drug and the response of the organism to the drug. Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D000242 Cyclic AMP An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH. Adenosine Cyclic 3',5'-Monophosphate,Adenosine Cyclic 3,5 Monophosphate,Adenosine Cyclic Monophosphate,Adenosine Cyclic-3',5'-Monophosphate,Cyclic AMP, (R)-Isomer,Cyclic AMP, Disodium Salt,Cyclic AMP, Monoammonium Salt,Cyclic AMP, Monopotassium Salt,Cyclic AMP, Monosodium Salt,Cyclic AMP, Sodium Salt,3',5'-Monophosphate, Adenosine Cyclic,AMP, Cyclic,Adenosine Cyclic 3',5' Monophosphate,Cyclic 3',5'-Monophosphate, Adenosine,Cyclic Monophosphate, Adenosine,Cyclic-3',5'-Monophosphate, Adenosine,Monophosphate, Adenosine Cyclic
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
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

M S Gaide, and J R Wiggins, and W S Fitterman, and J S Cameron, and R J Myerburg, and A L Bassett
August 1978, Journal of cyclic nucleotide research,
M S Gaide, and J R Wiggins, and W S Fitterman, and J S Cameron, and R J Myerburg, and A L Bassett
January 1974, The Journal of pharmacology and experimental therapeutics,
M S Gaide, and J R Wiggins, and W S Fitterman, and J S Cameron, and R J Myerburg, and A L Bassett
September 1981, Circulation research,
M S Gaide, and J R Wiggins, and W S Fitterman, and J S Cameron, and R J Myerburg, and A L Bassett
November 1983, The Anatomical record,
M S Gaide, and J R Wiggins, and W S Fitterman, and J S Cameron, and R J Myerburg, and A L Bassett
February 1980, The Journal of pharmacology and experimental therapeutics,
M S Gaide, and J R Wiggins, and W S Fitterman, and J S Cameron, and R J Myerburg, and A L Bassett
November 1991, Naunyn-Schmiedeberg's archives of pharmacology,
M S Gaide, and J R Wiggins, and W S Fitterman, and J S Cameron, and R J Myerburg, and A L Bassett
August 1987, Cardiovascular research,
M S Gaide, and J R Wiggins, and W S Fitterman, and J S Cameron, and R J Myerburg, and A L Bassett
January 1974, Recent advances in studies on cardiac structure and metabolism,
M S Gaide, and J R Wiggins, and W S Fitterman, and J S Cameron, and R J Myerburg, and A L Bassett
August 1977, Japanese journal of pharmacology,
M S Gaide, and J R Wiggins, and W S Fitterman, and J S Cameron, and R J Myerburg, and A L Bassett
May 1981, Archives internationales de physiologie et de biochimie,
Copied contents to your clipboard!