Effects of ageing on nicotine-induced contraction and substance P-like materials release in guinea-pig bronchus.
1. Effects of ageing on nicotine-induced contraction and release of substance P-like materials in the bronchial preparations from guinea-pigs of different ages were studied. 2. The pD2 value (potency) of nicotine decreased with age from 10 to 100 weeks. The pD2 value of substance P did not change with age suggesting that substance P receptor mechanisms do not alter with age. 3. The amount of substance P-like materials released by nicotine (10(-4) M) decreased with age from 10 to 100 weeks, supporting our previous findings that nicotine contracts the guinea-pig bronchus through the release of substance P-like materials. 4. These results suggest that the age-related decrease in the pD2 value (potency) of nicotine is due to the reduction in the amount of substance P-like materials released by nicotine.
Takayanagi
I
I
Department of Chemical Pharmacology, Toho University School of Pharmaceutical Sciences, Chiba, Japan.
Moriya
M
M
Kurata
R
R
Koike
K
K
D000375:Aging / Q000502:physiology*; D000818:Animals; D001980:Bronchi / Q000187:drug effects / Q000378:metabolism*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D009538:Nicotine / Q000494:pharmacology*; D018040:Receptors, Neurokinin-1; D017981:Receptors, Neurotransmitter / Q000378:metabolism; D013373:Substance P / Q000378:metabolism*
D018040:Receptors, Neurokinin-1; D017981:Receptors, Neurotransmitter; D013373:Substance P; D009538:Nicotine