[The muscarinic receptor subtype study of the action on lowering IOP of cholinomimetic drugs].
OBJECTIVE
Clarify the relationship between lowering intraocular pressure (IOP) action of cholinomimetic drugs and muscarinic receptor subtypes.


METHODS
Measuring rabbit IOP with gas driving ophthalmotonometer, measuring size of pupil with pupil rule and measuring contraction of rabbit iris by iris experiment in vitro. Figuring out pD2 of cholinomimetic drugs and pA2 of the antagonists of muscarinic receptor subtypes.


RESULTS
The order of effect on lowering IOP and miosis of cholinomimetic drugs is Erycibele Alkaloid > Aceclidine > Pilocarpine and the order of effect on constracting iris is Erycibele Alkaloid > Pilocarpine > Aceclidine. The sequence of antagonistic effect of subtype antagonists is 4-DAMP(M3) > Pirenzepine(M1) > Gallamine(M2).


CONCLUSIONS
Effect cholinomimetics on lowing IOP and miosis is primary mediated by M3 receptor, next by M1 receptor and has little relation with M2 receptor.
Wu
Y
Y
Department of Pharmacology, Sun Yet-sen University of Medical Sciences, Guangzhou 510089, China.
Peng
D
D
Zeng
S
S
Gu
Y
Y
D000818:Animals; D018678:Cholinergic Agents / Q000494:pharmacology*; D005260:Female; D007429:Intraocular Pressure / Q000187:drug effects*; D008297:Male; D008916:Miotics / Q000494:pharmacology; D018721:Muscarinic Agonists / Q000494:pharmacology; D010862:Pilocarpine / Q000494:pharmacology; D011812:Quinuclidines / Q000494:pharmacology*; D011817:Rabbits; D011976:Receptors, Muscarinic / Q000145:classification / Q000502:physiology
D018678:Cholinergic Agents; D008916:Miotics; D018721:Muscarinic Agonists; D011812:Quinuclidines; D011976:Receptors, Muscarinic; D010862:Pilocarpine; C084650:aceclidine