Muscarinic Cholinergic Binding in Rat Brain
Abstract
Binding sites with high affinity and specificity for [3H]quinuclidinyl benzilate (QNB) are present in homogenates of rat brain. The characteristics of the binding sites resemble those of muscarinic cholinergic receptors. Specific binding is saturable with respect to [3H]QNB and tissue concentration and is time-, temperature-, and pH-dependent. The bimolecular rate of association (2.0 × 108 M-1 min-1) and dissociation (1.2 × 10-2 min-1) at 35° indicate a dissociation constant of 60 pM and a density of 65 pmol/g of brain. Muscarinic antagonists and agonists displace specific [3H]QNB binding, while nicotinic and non-cholinergic drugs possess little affinity for [3H]QNB-binding sites.
- Publication:
-
Proceedings of the National Academy of Science
- Pub Date:
- May 1974
- DOI:
- 10.1073/pnas.71.5.1725
- Bibcode:
- 1974PNAS...71.1725Y