Effects of aging on alpha1-adrenoceptor mechanisms in the isolated mouse aortic preparation.
The effects of aging on alpha(1)-adrenoceptor (alpha(1)-AR)-mediated contractile response in endothelium-removed aortic preparations isolated from 5- to 40-week-old (5-, 6-, 8-, 10-, 20-, 40-weeks) mice were studied in the presence of propranolol. The potency of noradrenaline, estimated as its pD(2) value, increased with age from 5- to 10-weeks, but decreased thereafter with age from 10- to 40-weeks. However, the affinity of prazosin (pA(2) value) did not change with aging. These results suggest that age-related change in noradrenaline potency is not attributable to the change of drug affinity to alpha(1)-ARs, but is possibly due to drug affinity-unrelated factors such as change of the reserve of alpha(1)-ARs.
Tanaka
Yoshio
Y
Department of Chemical Pharmacology, Toho University School of Pharmaceutical Sciences, Funabashi, Chiba, Japan. yotanaka@phar.tohoku-u.ac.jp
Funabiki
Midori
M
Michikawa
Hiromi
H
Koike
Katsuo
K
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000375:Aging / Q000502:physiology*; D000818:Animals; D001013:Aorta, Thoracic / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation / Q000235:genetics; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D009119:Muscle Contraction / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D009638:Norepinephrine / Q000494:pharmacology; D011224:Prazosin / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D018340:Receptors, Adrenergic, alpha-1 / Q000235:genetics / Q000502:physiology*
D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D018340:Receptors, Adrenergic, alpha-1; D011433:Propranolol; D009638:Norepinephrine; D011224:Prazosin