Aging and vasoconstrictor responses mediated by alpha 2-adrenoceptors and 5-HT1 and 5-HT2 receptors.
The potencies of noradrenaline (NA) at producing alpha 2-adrenoceptor mediated contractions, and of 5-hydroxytryptamine (5-HT) at producing 5-HT1 and 5-HT2 receptor mediated contractions were investigated in rings of human saphenous vein obtained from varicose vein surgery. There was a significant negative correlation between agonist potency and age for NA at alpha 2-adrenoceptors (r = 0.52, n = 21, p < 0.05) and for 5-HT at both 5-HT1 (r = 0.47, n = 19, p < 0.05) and 5-HT2 (r = 0.54, n = 19, p < 0.05) receptors, so that both agonists were less potent with increasing age. This demonstrates an age-related decrease in alpha 2-adrenoceptor and 5-HT1 and 5HT2 mediated contractile responsiveness in the human saphenous vein.
Department of Physiology, Royal College of Surgeons in Ireland, Dublin.
J R
JR
Docherty
D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D000818:Animals; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007650:Ketanserin / Q000494:pharmacology; D008297:Male; D008719:Methiothepin / Q000494:pharmacology; D008875:Middle Aged; D009638:Norepinephrine / Q000502:physiology; D018341:Receptors, Adrenergic, alpha-2 / Q000502:physiology*; D011985:Receptors, Serotonin / Q000502:physiology*; D012501:Saphenous Vein / Q000502:physiology; D012701:Serotonin / Q000502:physiology; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology*
D018341:Receptors, Adrenergic, alpha-2; D011985:Receptors, Serotonin; D012701:Serotonin; D008719:Methiothepin; D007650:Ketanserin; D009638:Norepinephrine