The effect of 4-aminopyridine and its analogs on the specific binding of [3H]phencyclidine was investigated in rat brain homogenates. 4-Aminopyridine (4-AP) and 3,4-diaminopyridine displaced [3H]phencyclidine binding, while 3-aminopyridine was without effect. The concentrations of 4-AP required for inhibition of binding increased with increasing the ligand concentration, and the resultant Dixon plots indicated a competitive type of interaction. However, 4-AP also accelerated the dissociation rate of the ligand-receptor complex, suggesting that the effect of 4-AP on phencyclidine receptors in the brain might not be purely competitive.
Bibliographical noteFunding Information:
This work was supported by BRS Grant S07-RR05770. The authors would like to thank Ms. Renee Powe and Mrs. Pat Tretter for their excellent secretarial help, and Mr. Michael Gentry for his assistance.
- phencyclidine (PCP)
- potassium channel