The histamine H4 receptor antagonist JNJ7777120 induces increases in the histamine content of the rat conjunctiva.
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.
Zampeli
E
E
Department of Pharmacology, Medical School, University of Athens, Athens, Greece.
Thurmond
R L
RL
Tiligada
E
E
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
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