PMID- 3754173
OWN - NLM
STAT- MEDLINE
DCOM- 19860501
LR  - 20190511
IS  - 0007-1188 (Print)
IS  - 0007-1188 (Linking)
VI  - 87
IP  - 2
DP  - 1986 Feb
TI  - The binding of pirenzepine to digitonin-solubilized muscarinic acetylcholine 
      receptors from the rat myocardium.
PG  - 307-16
AB  - The binding of pirenzepine to digitonin-solubilized rat myocardial muscarinic 
      acetylcholine receptors has been examined at 4 degrees C. Solubilization produced 
      only small changes in the binding of N-methylscopolamine and atropine. In 
      contrast to the low affinity binding of pirenzepine found to be present in in the 
      membranes, high affinity binding was detected in the soluble preparation. In both 
      preparations, pirenzepine binding was complex. High affinity pirenzepine binding 
      (KD approximately 3 X 10(-8)M) to the soluble myocardial receptors could be 
      monitored directly using [3H]-pirenzepine. [3H]-pirenzepine-labelled soluble 
      myocardial receptors have a sedimentation coefficient of 11.1 s. This indicates 
      that [3H]-pirenzepine binds predominantly to the uncoupled form of the receptor. 
      However, [3H]-pirenzepine-agonist competition experiments indicated that the high 
      affinity pirenzepine binding sites are capable of coupling with a guanosine 
      5'-triphosphate (GTP)-binding protein. Pirenzepine affinities for the soluble 
      myocardial receptors were unaffected by their state of association with the 
      GTP-binding proteins found in the heart. The equilibrium binding properties of 
      the soluble cortical and myocardial receptors were very similar. However, the 
      binding kinetics of the myocardial receptor were much slower. It appears that the 
      membrane environment can affect the affinity of pirenzepine for the rat 
      myocardial muscarinic receptor. Removal of the constraint by solubilization 
      allows the expression of high affinity pirenzepine binding.
FAU - Birdsall, N J
AU  - Birdsall NJ
FAU - Hulme, E C
AU  - Hulme EC
FAU - Keen, M
AU  - Keen M
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Br J Pharmacol
JT  - British journal of pharmacology
JID - 7502536
RN  - 0 (Benzodiazepinones)
RN  - 0 (Receptors, Muscarinic)
RN  - 0 (Scopolamine Derivatives)
RN  - 3G0285N20N (Pirenzepine)
RN  - 5RY0UWH1JL (Oxotremorine)
RN  - 63939-65-1 (oxotremorine M)
RN  - KOO5CM684H (Digitonin)
RN  - VDR09VTQ8U (N-Methylscopolamine)
SB  - IM
MH  - Animals
MH  - Benzodiazepinones/*metabolism
MH  - Binding, Competitive
MH  - Cell Membrane/metabolism
MH  - Centrifugation, Density Gradient
MH  - Digitonin
MH  - In Vitro Techniques
MH  - Myocardium/*metabolism
MH  - N-Methylscopolamine
MH  - Oxotremorine/analogs & derivatives/metabolism
MH  - Pirenzepine
MH  - Rats
MH  - Receptors, Muscarinic/*metabolism
MH  - Scopolamine Derivatives/metabolism
MH  - Solubility
PMC - PMC1916543
EDAT- 1986/02/01 00:00
MHDA- 1986/02/01 00:01
PMCR- 1987/02/01
CRDT- 1986/02/01 00:00
PHST- 1986/02/01 00:00 [pubmed]
PHST- 1986/02/01 00:01 [medline]
PHST- 1986/02/01 00:00 [entrez]
PHST- 1987/02/01 00:00 [pmc-release]
AID - 10.1111/j.1476-5381.1986.tb10819.x [doi]
PST - ppublish
SO  - Br J Pharmacol. 1986 Feb;87(2):307-16. doi: 10.1111/j.1476-5381.1986.tb10819.x.