|
KMID : 0043319940170060443
|
|
Archives of Pharmacal Research
1994 Volume.17 No. 6 p.443 ~ p.451
|
|
|
Selectivity of Oxomemazine for the M1 Muscarinic Receptors
|
|
Lee Shin-Woong
Woo Chang-Woo
Kim Jeung-Gu
|
|
|
Abstract
|
|
|
|
The binding characteristics of pirenzepine and oxomemazine to muscarinic receptor were studied to evaluate the selectivity of oxomemazine for the muscarinic receptor subtypes in rat cerebral microsomes. Equililbrium dissociation constant quinuclidinyl benzilate determined from saturation isotherms was 64-pM. Analysis of the pirenzepine inghibition curve of []QNB binding to cerebral microsome indicatd the presence of two receptor subtypes with high two receptor subypes with about 20-fold difference in the affinity for high ) affinity sites. The percentage populations of $M_1{\;} and M_3$, /TEX> receptors to the total receptors were 61 : 39, and those of receptors 39 : 61, resepectively. Both pirenzepine and oxomemazine increaed the value for without affecting the binding site concentrations and Hii coefficient for the without affecting the binding site concentractions and Hill coefficient for the [H]QNB binding. Oxomemazine had a 10-fold higher affinity at receptors than at receptors, and pirenzepine a 8-fold higher affinity at receptors were of receptors and 71% of receptors. However, for oxomemazine and for pirenzepine were composed of a uniform population. These results suggest that oxomemazine could be classified as a selective drug for receptors and also demonstrate that rat cerebral microsomes contain three different subtypes of and the other site which is different from $M_1, {\;} M_2$, /TEX> receptors.
|
|
|
KEYWORD
|
|
|
Muscarinic receptor subtype, Oxomemazine, Prienzepine, Receptor binding, Rat cerebrum
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
  
|