Although the H4 receptor localisation in the eye is unresolved, this study aimed to investigate the effects of the H4 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 H4 receptor in the rat eye and address questions on the localization and the role of the receptor in ocular inflammation.