[Comparison of functional alpha 1-adrenoceptor subtypes in aortae between 12 month- and 10 week-old rats]

Sheng Li Xue Bao. 1997 Aug;49(4):414-8.
[Article in Chinese]

Abstract

The distribution of alpha 1-adrenoceptor and its subtypes in isolated aortae was compared between 12 month- and 10 week-old Wistar rats by determinating vasoconstrictor responses. In the 12 month-old rats, compared with the 10 week-old rats, (1) the maximal contraction induced by norepinephrine (NE) was reduced, without significant alteration of pD2 value; (2) the inhibitory effect of chlorethylclonidine (an irreversible antagonist for alpha 1B and alpha 1D subtype) on NE-induced contraction was weaker; (3) using NE as an agonist, the pA2 value for WB4101 (an alpha 1A- and alpha 1D-selective antagonist) was not changed, but the pA2 value for BMY7378 (an alpha 1D-selective antagonist) was decreased, while the pA2 value for sertindole (an alpha 1A-selective antagonist) was increased. Thus, differently from the 10 week-old rats in which only alpha 1D-adrenoceptors mediate NE-induced contraction in aortae, both alpha 1A- and alpha 1D-adrenoceptors (mainly alpha 1A) mediate the response in the 12 month-old rats.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenergic alpha-Agonists / pharmacology
  • Adrenergic alpha-Antagonists / pharmacology
  • Aging / metabolism*
  • Animals
  • Aorta, Thoracic / metabolism*
  • Male
  • Norepinephrine / pharmacology
  • Piperazines / pharmacology
  • Rats
  • Rats, Wistar
  • Receptors, Adrenergic, alpha-1 / classification*
  • Receptors, Adrenergic, alpha-1 / metabolism*

Substances

  • Adrenergic alpha-Agonists
  • Adrenergic alpha-Antagonists
  • Piperazines
  • Receptors, Adrenergic, alpha-1
  • BMY 7378
  • Norepinephrine