Effects of histamine and related compounds on the bovine iris dilator

Chiaki Kamei, Yukio Sugimoto, Yasushi Okumura

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Effects of histamine and related compounds on the bovine iris dilator were investigated. Histamine caused a concentration- related contraction of the bovine iris dilator and IC50 was 1.57 x 10-7 M. The potency of histamine on the bovine iris dilator was almost the same as that observed in guinea pig ileum. Histamine- induced contraction of the bovine iris dilator was antagonized by the H1 antagonists pyrilamine, diphenhydramine and chlorpheniramine, whereas pretreatment with the H2 antagonists cimetidine and ranitidine was not effective. In addition, histamine and the H1 agonist 2-methylhistamine caused a contraction of bovine iris dilator, but the H2 agonist 4-methylhistamine was not effective. An H3 antagonist, thioeramide, also had no contractive effects on the bovine iris dilator. The bovine iris dilator contained a considerable amount of histamine, which was not released by compound 48/80, substance P or by increasing K+ concentration in the medium. In conclusion, histamine caused a potent contraction of the bovine iris dilator via H1 receptor, and this muscle showed a high sensitivity to histamine similar to guinea pig ileum.

Original languageEnglish
Pages (from-to)273-278
Number of pages6
JournalMethods and Findings in Experimental and Clinical Pharmacology
Volume18
Issue number4
Publication statusPublished - Jul 9 1996

Keywords

  • 2- Methylhistamine
  • Bovine iris dilator
  • H antagonist
  • Histamine
  • Thioperamide

ASJC Scopus subject areas

  • Pharmacology
  • Pharmacology (medical)

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