PMID- 2657440
OWN - NLM
STAT- MEDLINE
DCOM- 19890707
LR  - 20190725
IS  - 0028-1298 (Print)
IS  - 0028-1298 (Linking)
VI  - 339
IP  - 1-2
DP  - 1989 Jan-Feb
TI  - Anti-cholinergic effect of verapamil on the muscarinic acetylcholine 
      receptor-gated K+ channel in isolated guinea-pig atrial myocytes.
PG  - 244-6
AB  - Effects of verapamil on the acetylcholine (ACh)-induced K+ current were examined 
      in single atrial cells, using the tight-seal whole-cell clamp technique. The 
      pipette solution contained guanosine-5'-triphosphate (GTP) or 
      guanosine-5'-O-(3-thiotriphosphate) (GTP-gamma S, a non-hydrolysable GTP 
      analogue). In GTP-loaded cells, ACh induced a specific K+ current, which is known 
      to be mediated by pertussis toxin-sensitive GTP-binding (G) proteins. Verapamil 
      (0.1-100 microM) depressed the ACh-induced K+ current in a 
      concentration-dependent fashion. In GTP-gamma S-loaded cells, the K+ current 
      remained persistently after wash-out of ACh, probably due to irreversible 
      activation of G proteins by GTP-gamma S. Verapamil (0.1-100 microM) also 
      depressed the intracellular GTP-gamma S-induced K+ current. However, the 
      magnitude of verapamil-depression of the K+ current in GTP-gamma S-loaded cells 
      was significantly smaller than that in GTP-loaded cells at concentrations between 
      1 and 10 microM of the drug. From these results, it is suggested that verapamil 
      may block not only the function of muscarinic ACh receptors but also of G 
      proteins and/or the K+ channel itself and thereby depress the ACh-induced K+ 
      current in isolated atrial myocytes.
FAU - Ito, H
AU  - Ito H
AD  - 2nd Department of Internal Medicine, Faculty of Medicine, University of Tokyo, 
      Japan.
FAU - Takikawa, R
AU  - Takikawa R
FAU - Kurachi, Y
AU  - Kurachi Y
FAU - Sugimoto, T
AU  - Sugimoto T
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Germany
TA  - Naunyn Schmiedebergs Arch Pharmacol
JT  - Naunyn-Schmiedeberg's archives of pharmacology
JID - 0326264
RN  - 0 (Parasympatholytics)
RN  - 0 (Potassium Channels)
RN  - 0 (Receptors, Cholinergic)
RN  - 0 (Receptors, Muscarinic)
RN  - 0 (Thionucleotides)
RN  - 37589-80-3 (Guanosine 5'-O-(3-Thiotriphosphate))
RN  - 86-01-1 (Guanosine Triphosphate)
RN  - CJ0O37KU29 (Verapamil)
RN  - N9YNS0M02X (Acetylcholine)
SB  - IM
MH  - Acetylcholine/antagonists & inhibitors
MH  - Animals
MH  - Guanosine 5'-O-(3-Thiotriphosphate)
MH  - Guanosine Triphosphate/analogs & derivatives/pharmacology
MH  - Guinea Pigs
MH  - Heart/*drug effects
MH  - In Vitro Techniques
MH  - Myocardium/*cytology/metabolism
MH  - *Parasympatholytics
MH  - Potassium Channels/*drug effects
MH  - Receptors, Cholinergic/*drug effects
MH  - Receptors, Muscarinic/*drug effects
MH  - Thionucleotides/pharmacology
MH  - Verapamil/*pharmacology
EDAT- 1989/01/01 00:00
MHDA- 1989/01/01 00:01
CRDT- 1989/01/01 00:00
PHST- 1989/01/01 00:00 [pubmed]
PHST- 1989/01/01 00:01 [medline]
PHST- 1989/01/01 00:00 [entrez]
AID - 10.1007/BF00165150 [doi]
PST - ppublish
SO  - Naunyn Schmiedebergs Arch Pharmacol. 1989 Jan-Feb;339(1-2):244-6. doi: 
      10.1007/BF00165150.