Twenty-four hour variation of α1-adrenergic receptors in the pineal gland of the male Syrian hamster

Andreas Pangerl, Brigitte Pangerl, Russel J. Reiter, George M. Vaughan, David J. Jones

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


Specific binding of [125I]iodo-[β-(4-hydroxyphenyl)-ethylaminomethyl]tetralo ne ([125I]HEAT) was used to assess α1-adrenergic receptors on pineal gland membranes of male Syrian hamsters (Mesocricetus auratus) housed under a 14:10 h light-dark cycle (lights on at 06.00 h). Saturation experiments with pooled pineal membrane preparations showed the presence of α1-adrenergic receptor sites (dissociation constant Kd approx. 0.1 nM). Analysis of 4 time points indicated no significant change in Kd, but significant (P < 0.01) changes of receptor density (Bmax) with a minimum recorded at night. Binding of a constant amount of [125I]HEAT (200 pM) to pineal membranes at 8 time points exhibited a circadian variation (P < 0.001) of receptor density with lowest values around midnight and highest levels during daytime.

Original languageEnglish (US)
Pages (from-to)166-169
Number of pages4
JournalBrain Research
Issue number1
StatePublished - Jun 19 1989


  • Circadian variation
  • Pineal gland
  • α-Adrenoceptor

ASJC Scopus subject areas

  • Neuroscience(all)
  • Molecular Biology
  • Clinical Neurology
  • Developmental Biology


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