[Effect of pH on muscarinic antagonist selectivity].
The results of in vitro experiments showed that the receptor selectivity of the M-cholinoblocker tropacin (in contrast to that of amedine) is pH-dependent. A difference observed in the characteristics of tropacin selectivity in vivo and in vitro is probably explained by dissimilar conditions for the ligand interaction with M-cholinoreceptors in the organism and in the in vitro experiments. It is suggested that certain short-time (transient) local pH changes capable of affecting the ligand--receptor interaction parameters may take place in the synaptic cleft in the course of the neurotransmission.
Kosmachev
A B
AB
Institute of Toxicology, Ministry of Public Health of the Russian Federation, ul. Bekhtereva 1, St. Petersburg, 193019 Russia.
Iakhontova
M B
MB
Titkova
T A
TA
Fil'ko
O A
OA
Ramsh
S M
SM
D000818:Animals; D001115:Arecoline / Q000378:metabolism*; D001921:Brain / Q000378:metabolism; D004006:Dichlorvos / Q000506:poisoning; D005260:Female; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008297:Male; D018727:Muscarinic Antagonists / Q000378:metabolism / Q000494:pharmacology*; D009206:Myocardium / Q000378:metabolism; D011869:Radioligand Assay; D051381:Rats; D011976:Receptors, Muscarinic / Q000378:metabolism*; D014202:Tremor / Q000517:prevention & control; D014326:Tropanes / Q000378:metabolism*
D018727:Muscarinic Antagonists; D011976:Receptors, Muscarinic; D014326:Tropanes; C003727:tropacine; D001115:Arecoline; D004006:Dichlorvos