PMID: 208010May 5, 1978Paper

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

Naunyn-Schmiedeberg's Archives of Pharmacology
H J SchümannG Schramm

Abstract

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 i...Continue Reading

References

May 5, 1978·Naunyn-Schmiedeberg's Archives of Pharmacology·J Wagner, O E Brodde
Jan 1, 1972·European Journal of Pharmacology·J J Parr, P R Urquilla
Oct 3, 1974·The New England Journal of Medicine·L I Goldberg
Aug 1, 1967·British Journal of Pharmacology and Chemotherapy·B G Benfey, D R Varma
Mar 1, 1964·The Journal of Pharmacy and Pharmacology·E J ARIUENS, A M SIMONIS

❮ Previous
Next ❯

Citations

Mar 1, 1996·Cardiovascular Drugs and Therapy·G Abou-MohamedR W Caldwell
Jul 1, 1992·Naunyn-Schmiedeberg's Archives of Pharmacology·U JahnelH Nawrath
Sep 1, 1979·Naunyn-Schmiedeberg's Archives of Pharmacology·H J Schümann, O E Brodde
Jul 1, 1984·Naunyn-Schmiedeberg's Archives of Pharmacology·R R RuffoloJ S Horng
Jan 1, 1989·Basic Research in Cardiology·W SchmitzJ Scholz
Jul 21, 1994·European Journal of Pharmacology·S L BuzzardR H Kennedy
May 23, 1996·European Journal of Pharmacology·A P WilliamsonR H Kennedy
Jan 1, 1982·General Pharmacology·A G TahilianiJ H McNeill
Jan 1, 1981·Comparative Biochemistry and Physiology. C: Comparative Pharmacology·G Stene-Larsen
Nov 1, 1988·Proceedings of the National Academy of Sciences of the United States of America·M Apkon, J M Nerbonne
Oct 1, 1990·British Journal of Clinical Pharmacology·J P McKaigue, D W Harron
Jan 1, 1988·Clinical and Experimental Pharmacology & Physiology·A De Luca, M J Rand
Jan 1, 1991·The Journal of Pharmacy and Pharmacology·J P SpiersR Wilson
Jan 1, 1990·International Journal of Cardiology·C J MurdockR R Taylor
Feb 7, 2002·The Journal of Pharmacy and Pharmacology·Cristina O SilvaSaad Lahlou
Dec 1, 1989·Circulation·S K VarmaM D Feldman
Jun 1, 1994·Journal of Biomedical Science·M.-J. SuS.-H. Chu
Jan 1, 1986·British Journal of Pharmacology·L Canga, L Sterin-Borda

❮ Previous
Next ❯

Related Concepts

Related Feeds

Adrenergic Receptors: Trafficking

Adrenergic receptor trafficking is an active physiological process where adrenergic receptors are relocated from one region of the cell to another or from one type of cell to another. Discover the latest research on adrenergic receptor trafficking here.