title: The histamine H4 receptor antagonist JNJ7777120 induces increases in the histamine content of the rat conjunctiva.
abstract: OBJECTIVE
  Although the H(4) receptor localisation in the eye is unresolved, this study aimed to investigate the effects of the H(4) receptor antagonist JNJ7777120 in a model of experimental conjunctivitis.
  
  
  METHODS
  JNJ7777120, at 0.005-1 mmol/l, was instilled into the lower conjunctival fornix of normal and compound 48/80 (C48/80)-challenged eyes of male Wistar rats, in the absence or presence of 40 mg/ml disodium cromoglycate (DSCG). Conjunctival histamine content was quantified 20 min post-challenge. Statistical analyses were performed by ANOVA.
  
  
  RESULTS
  JNJ7777120 increased dose-dependently (r = 0.784, p < 0.001) the conjunctival histamine content. In the C48/80-challenged eye no effect of the antagonist was observed. Co-administration of JNJ7777120 with DSCG resulted in a biphasic action of JNJ7777120, implying a competitive action of the two agents.
  
  
  CONCLUSIONS
  These data suggest a functionality of the H(4) receptor in the rat eye and address questions on the localization and the role of the receptor in ocular inflammation.
authors.affiliation: Department of Pharmacology, Medical School, University of Athens, Athens, Greece.
authors.forename: E
authors.initials: E
authors.lastname: Zampeli
authors.forename: R L
authors.initials: RL
authors.lastname: Thurmond
authors.forename: E
authors.initials: E
authors.lastname: Tiligada
mesh_terms: D000818:Animals; D003228:Conjunctiva / Q000187:drug effects* / Q000378:metabolism; D003231:Conjunctivitis / Q000139:chemically induced / Q000378:metabolism; D006632:Histamine / Q000378:metabolism*; D006633:Histamine Antagonists / Q000494:pharmacology*; D007211:Indoles / Q000494:pharmacology*; D008297:Male; D010879:Piperazines / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D043562:Receptors, G-Protein-Coupled / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011968:Receptors, Histamine / Q000378:metabolism; D000074040:Receptors, Histamine H4; D003189:p-Methoxy-N-methylphenethylamine
chemical_list: D006633:Histamine Antagonists; C498828:Hrh4 protein, rat; D007211:Indoles; D010879:Piperazines; D043562:Receptors, G-Protein-Coupled; D011968:Receptors, Histamine; D000074040:Receptors, Histamine H4; D003189:p-Methoxy-N-methylphenethylamine; C484309:1-((5-chloro-1H-indol-2-yl)carbonyl)-4-methylpiperazine; D006632:Histamine