• Ten normal human volunteers participated in a two-part study of H2-receptor activity in the ocular surface. Dimethylaminopropylisothiourea (trivial name, dimaprit dihydrochloride), a highly selective H2-receptor agonist, produced vasodilation without itch. Pretreatment with the H2-receptor antagonist, cimetidine, significantly blocked the vasodilatory effect of dimethylaminopropylisothiourea, whereas pretreatment with the H1-receptor antagonist, antazoline phosphate, did not. We conclude that H2-receptors are present in the human ocular surface.
Abelson MB, Udell IJ. H2-Receptors in the Human Ocular Surface. Arch Ophthalmol. 1981;99(2):302-304. doi:10.1001/archopht.1981.03930010304018