The antimuscarinic activity of a dopamine receptor agonist (RDS-127) differentiates M2-muscarinic receptors of heart, ileum and trachea in guinea-pig.
The antimuscarinic action of a dopamine receptor agonist, 2-di-n-propylamino-4,7-dimethoxyindane (RDS-127) was evaluated using guinea-pig isolated electrically paced left atria, spontaneously beating atria, ileal longitudinal muscle and tracheal strip. RDS-127 competitively antagonized the responses to carbachol in all these tissues. RDS-127 exhibits higher selectivity for tracheal M2-muscarinic receptors than for cardiac and ileal receptors. In addition, the affinity of RDS-127 towards cardiac M2-muscarinic receptors was also greater than towards ileum. RDS-127 did not show any selectivity for M2-muscarinic receptors mediating negative inotropic and chronotropic effects.
Sahin
I
I
Hacettepe University, Faculty of Medicine, Department of Pharmacology, Ankara, Turkey.
Ilhan
M
M
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D015259:Dopamine Agents / Q000494:pharmacology*; D004558:Electric Stimulation; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D007189:Indans / Q000494:pharmacology*; D007192:Indenes / Q000494:pharmacology*; D008297:Male; D009928:Organ Specificity; D010276:Parasympatholytics; D011976:Receptors, Muscarinic / Q000187:drug effects*; D014132:Trachea / Q000187:drug effects
D015259:Dopamine Agents; D007189:Indans; D007192:Indenes; D010276:Parasympatholytics; D011976:Receptors, Muscarinic; D001285:Atropine; C035604:2-N,N-di-n-propylamino-4,7-dimethoxyindan