title: Effect of ageing on response to nicotine in rabbit bronchial preparation.
abstract: 1. Effect of ageing on the response to nicotine was tested in the bronchial muscle preparations from 5, 13, 100 and 125 week-old rabbits. The pD2 value (potency) of nicotine significantly increased in the preparation from the 125 week-old rabbits. No age-related change was found in the pD2 value of carbamylcholine or pA2 value of atropine. 2. No age-related change in characteristics of nicotine receptors. Choline acetyltransferase activity, the amount of acetylcholine released by nicotine and acetylcholineesterase activity decreased in the preparations from the 125 week-old rabbits. 3. Decrease in the pD2 value of nicotine in the preparation from the older rabbit is due to a decline in choline acetyltransferase activity followed by a reduction in the acetylcholine released, and not to a change in characteristics of nicotine receptors. 4. These results also suggest that enzymes may be influenced more easily with age than drug receptors.
authors.affiliation: Department of Chemical Pharmacology, Toho University School of Pharmaceutical Sciences, Chiba, Japan.
authors.forename: I
authors.initials: I
authors.lastname: Takayanagi
authors.forename: M
authors.initials: M
authors.lastname: Moriya
authors.forename: Y
authors.initials: Y
authors.lastname: Kizawa
authors.forename: K
authors.initials: K
authors.lastname: Koike
authors.forename: M
authors.initials: M
authors.lastname: Shinkai
authors.forename: H
authors.initials: H
authors.lastname: Murakami
mesh_terms: D000109:Acetylcholine / Q000378:metabolism / Q000494:pharmacology; D000110:Acetylcholinesterase / Q000378:metabolism; D000375:Aging / Q000502:physiology*; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001980:Bronchi / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D002217:Carbachol / Q000494:pharmacology; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D005260:Female; D006584:Hexamethonium Compounds / Q000494:pharmacology; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D008566:Membranes / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects* / Q000378:metabolism; D009538:Nicotine / Q000494:pharmacology*; D011817:Rabbits; D011978:Receptors, Nicotinic / Q000187:drug effects / Q000378:metabolism
chemical_list: D006584:Hexamethonium Compounds; D011978:Receptors, Nicotinic; D009538:Nicotine; D001285:Atropine; D002217:Carbachol; D002795:Choline O-Acetyltransferase; D000110:Acetylcholinesterase; D000109:Acetylcholine