Is [3H]-tiotidine a specific ligand for the H2-receptor?

Shmuel Batzri, John W. Harmon

Research output: Contribution to journalArticle

Abstract

The H2-antagonist tiotidine inhibited the H2-receptor-mediated, histamine-induced increase in cyclic AMP in dispersed mucosal cells from guinea pig stomach (Ki, 4 × 10-8 M). The radiolabeled [3H]-tiotidine bound specifically and reversibly to the same cells with a half-maximal binding occurring at 5 × 10-7M tiotidine. The dissociation of bound [3H]-tiotidine from gastric cells and the Scatchard analysis of the binding data suggest the existence of additional binding sites for tiotidine. Eight other antagonists which inhibited the H2-receptor-mediated increase in cyclic AMP also inhibited [3H]-tiotidine binding. However, the potencies of these agents for binding did not agree with their effects on cyclic AMP. The selective H2-agonists impromidine and dimaprit which increased cyclic AMP caused only partial inhibition of [3H]-tiotidine binding. These results demonstrate that [3H]-tiotidine has limited binding to the H2-receptors and as such [3H]-tiotidine is not a suitable ligand for labelling the H2-receptor on gastric mucosal cells.

Original languageEnglish (US)
Pages (from-to)241-247
Number of pages7
JournalPharmacology
Volume32
Issue number5
DOIs
StatePublished - Jan 1 1986
Externally publishedYes

Keywords

  • Cyclic AMP
  • H-antagonist
  • H-receptor binding
  • Tiotidine binding

ASJC Scopus subject areas

  • Pharmacology

Fingerprint Dive into the research topics of 'Is [<sup>3</sup>H]-tiotidine a specific ligand for the H<sub>2</sub>-receptor?'. Together they form a unique fingerprint.

  • Cite this