Age-dependent decrease in histamine H1 receptor in human brains revealed by PET

Kazuhiko Yanai, Takehiko Watanabe, Kenichi Meguro, Hiroyuki Yokoyama, Ikuro Sato, Hironobu Sasano, Masatoshi Itoh, Ren Iwata, Toshihiro Takahashi, Tatsuo Ido

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54 Citations (Scopus)


Age-related changes in histamine H1 receptors were studied using [11C]pyrilamine or [11C]doxepin by positron emission tomography (PET). The frontal, parietal and temporal cortices showed age-related decreases in binding of approximately 13% per decade. In contrast, the thalamus showed no apparent decrease in binding during normal ageing because of its higher nonspecific binding. Post mortem studies also indicated that the nonspecific binding of [3H]pyrilamine in the thalamus was approximately 112% higher than that in the cortex. However, no significant decrease in histamine H1 receptors with age was observed by in vitro binding assays of autopsied human frontal cortex. Possible reasons are given for the larger effects of age observed in the PET study than in the in vitro post mortem binding study.

Original languageEnglish
Pages (from-to)433-436
Number of pages4
Issue number5
Publication statusPublished - 1992 May


  • Ageing
  • Frontal cortex
  • Histamine
  • Histamine H
  • Human brain
  • In vitro study
  • In vivo study
  • Positron emission tomography
  • Receptors


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