Antagonism of novel inotropic agents at A1 adenosine receptors and m-cholinoceptors in human myocardium

1990 ◽  
Vol 341 (6) ◽  
Author(s):  
Martin Ungerer ◽  
Michael B�hm ◽  
RobertH.G. Schwinger ◽  
Erland Erdmann
Keyword(s):  
Adenosine Receptors ◽  
Human Myocardium ◽  
Inotropic Agents ◽  
A1 Adenosine Receptors

Coupling of M-cholinoceptors and A1 adenosine receptors in human myocardium

1994 ◽  
Vol 266 (5) ◽  
pp. H1951-H1958 ◽  
Author(s):  
M. Bohm ◽  
P. Gierschik ◽  
R. H. Schwinger ◽  
R. Uhlmann ◽  
E. Erdmann
Keyword(s):  
G Protein ◽  
Adenosine Receptors ◽  
Binding Sites ◽  
Human Myocardium ◽  
Force Of Contraction ◽  
High Affinity ◽  
Alpha Subunits ◽  
Number Of Binding Sites ◽  
A1 Adenosine Receptors ◽  
Gamma S

This study investigated the coupling of M-cholinoceptors and A1 adenosine receptors in human myocardium. Carbachol reduced force of contraction in atria and ventricles by 60 and 35% (in the presence of 0.03 microM isoprenaline), respectively. Addition of (-)-N6-(2-phenylisopropyl)adenosine (R-PIA) in the presence of carbachol did not further reduce force of contraction. R-PIA reduced force of contraction less than carbachol in atria (ventricles) by 35% (25%), but addition of carbachol after R-PIA reduced force of contraction further by 35% (15%). Carbachol increased 35S-labeled guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S) binding maximally 14-fold only when GDP was present by an excess of > 100 times [35S]GTP gamma S, while R-PIA increased binding only 2-fold. Activation of [35S]GTP gamma S binding by A1 adenosine receptor and M-cholinoceptor stimulation was antagonized by theophylline and atropine, respectively. Addition of R-PIA to carbachol did not further increase [35S]GTP gamma S binding. Activation of high-affinity [35S]GTP gamma S binding by agonists showed that carbachol activated [35S]GTP gamma S binding to 20 pmol/mg protein [35S]GTP gamma S binding sites, i.e., 25% of the total number of binding sites (80 pmol/mg protein). With R-PIA, activation of high-affinity [35S]GTP gamma S binding could not reliably be detected with this technique. From the number of M-cholinoceptors (atria, 360 fmol/mg protein; ventricle, 270 fmol/mg protein), it is estimated that 1 M-cholinoceptor activates approximately 50-80 G protein alpha-subunits in atria and ventricles, respectively. It is concluded that stimulation of M-cholinoceptors but not A1 adenosine receptors is able to maximally activate a pool of G protein alpha-subunits.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Species differences in structure-activity relationships of adenosine agonists and xanthine antagonists at brain A1 adenosine receptors

FEBS Letters ◽  
1986 ◽  
Vol 209 (1) ◽  
pp. 122-128 ◽  
Author(s):  
Dieter Ukena ◽  
Kenneth A. Jacobson ◽  
William L. Padgett ◽  
Cristina Ayala ◽  
Mah T. Shamim ◽  
...  
Keyword(s):  
Adenosine Receptors ◽  
Species Differences ◽  
Structure Activity Relationships ◽  
Structure Activity ◽  
Adenosine Agonists ◽  
A1 Adenosine Receptors

scholarly journals Immunolocalization of A1 Adenosine Receptors in Mammalian Spermatozoa

2000 ◽  
Vol 48 (9) ◽  
pp. 1163-1171 ◽  
Author(s):  
A. Minelli ◽  
C. Allegrucci ◽  
P. Piomboni ◽  
R. Mannucci ◽  
C. Lluis ◽  
...  
Keyword(s):  
Adenosine Receptors ◽  
A1 Adenosine Receptors ◽  
Mammalian Spermatozoa

Loss of A1 adenosine receptors in human temporal lobe epilepsy

1996 ◽  
Vol 710 (1-2) ◽  
pp. 56-68 ◽  
Author(s):  
M. Glass ◽  
R.L.M. Faull ◽  
J.Y. Bullock ◽  
K. Jansen ◽  
E.W. Mee ◽  
...  
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Adenosine Receptors ◽  
A1 Adenosine Receptors ◽  
Human Temporal Lobe

Anemia up-regulates pontine A1 adenosine receptors in fetal sheep

1992 ◽  
Vol 579 (2) ◽  
pp. 291-295 ◽  
Author(s):  
Brian J. Koos ◽  
Thomas F. Murray ◽  
Waleed Doany
Keyword(s):  
Adenosine Receptors ◽  
Fetal Sheep ◽  
A1 Adenosine Receptors

Inhibition of brain adenylate cyclase by A1 adenosine receptors: Pharmacological characteristics and locations

1983 ◽  
Vol 267 (1) ◽  
pp. 123-129 ◽  
Author(s):  
C. Ebersolt ◽  
J. Premonta ◽  
A. Prochiantz ◽  
M. Perez ◽  
J. Bockaert
Keyword(s):  
Adenylate Cyclase ◽  
Adenosine Receptors ◽  
A1 Adenosine Receptors
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