COOPERATIVITY PATTERN IN THE INTERACTION OF THE ANTI-ESTROGEN DRUG CLOMIPHENE WITH THE MUSCARINIC RECEPTORS

  • 1 January 1982
    • journal article
    • research article
    • Vol. 21  (2) , 287-293
Abstract
The possible interaction between the muscarinic receptors and the antiestrogenic drug clomiphene citrate was investigated in competition experiments using the highly specific antagonist 3H-N-methyl-4-piperidyl benzilate (4-NMPB) in various regions of rat brain. Clomiphene can displace muscarinic antagonists from their receptor-ligand complexes. Binding analyses and determinations of the kinetics of dissociation of [3H]4-NMPB-receptor complexes indicate the binding of more than 1 molecule of clomiphene in a positively cooperative pattern. The nonsteroidal antiestrogenic drugs, e.g., clomiphene, may exert their effects not only through the specific estrogen receptor but also in conjunction with muscarinic system.