[Inhibitory effect of 6 beta-acetoxy nortropane on respiration].
6 beta-AN (6 beta-acetoxy nortropane), a novel selective M2-receptor agonist, caused decrease in FR, TV, MVV and pO2 and increase of pCO2 when intravenous injection of 10 micrograms.kg-1 in conscious rabbits or 2, 5, 20 micrograms.kg-1 in conscious dogs was given (P < 0.05 or 0.01). The inhibitory effect on MVV exhibited a dose-dependent relationship. Small doses of 6 beta-AN icv (0.5, 1, 2, 4 micrograms.kg-1 in the conscious rabbits) and iva (0.25, 0.5 and 1.0 micrograms.kg-1 in anesthetized dogs) decreased FR, TV, MVV and pO2 and increased pCO2 as well. These results were reversed after administration of AF-DX116 and enhanced after administration of pirenzepine. Thus, it appears that the inhibitory action of 6 beta-AN on respiration might be related to stimulation of the inhibitory M2 cholinergic receptor in respiratory center.
Department of Pharmacology, Xuzhou Medical College.
B
B
Yao
J L
JL
Zheng
W
W
Qin
C F
CF
Bian
D000818:Animals; D004285:Dogs; D005260:Female; D008297:Male; D018721:Muscarinic Agonists; D009662:Nortropanes / Q000494:pharmacology*; D010276:Parasympatholytics / Q000494:pharmacology; D010890:Pirenzepine / Q000031:analogs & derivatives / Q000494:pharmacology; D011817:Rabbits; D011976:Receptors, Muscarinic / Q000187:drug effects*; D012119:Respiration / Q000187:drug effects*; D012125:Respiratory Center / Q000187:drug effects; D013990:Tidal Volume / Q000187:drug effects
D018721:Muscarinic Agonists; D009662:Nortropanes; D010276:Parasympatholytics; D011976:Receptors, Muscarinic; C071344:6-acetoxynortropane; D010890:Pirenzepine; C048593:otenzepad