Elsevier

Experimental Eye Research

Volume 67, Issue 3, September 1998, Pages 341-346
Experimental Eye Research

Regular article
Regulation of Ocular Mucin Secretion by P2Y2Nucleotide Receptors in Rabbit and Human Conjunctiva

https://doi.org/10.1006/exer.1998.0520Get rights and content

Abstract

The effects of adenine analogues on secretion of high molecular weight, mucin-like glycoproteins (mucins) by conjunctival goblet cells were investigated using isolated rabbit and human conjunctiva. Mucin secretion was assayed using a quantitative dot-blot assay ofHelix pomatiaagglutinin-horseradish peroxidase binding to mucins absorbed to nitrocellulose filters. In rabbit conjunctiva, exogenous ATP (10−7–10−3m) induced a concentration-dependent, four-fold increase in mucin secretion that reached a plateau 15 min after drug addition. The rank order of potency of agonists was UTP⩾ATPγS>ATP>ITP>ADP⪢AMP. Adenosine, α,β-methylene- ATP and β,γ-methylene-ATP were ineffective in stimulating mucin release. The response to ATP was unmodified by the putative P2purinergic antagonists suramin or reactive blue (5×10−5m). In human conjunctiva, ATP and UTP were nearly equipotent in stimulating mucin secretion with an EC50≅5×10−6m. These findings demonstrate that rabbit and human conjunctival cells contain functional P2Y2(formerly designated as P2U) nucleotide receptors that govern mucin secretion. These receptors may provide useful pharmacological targets for therapeutic modulation of tear film mucins in dry-eye disorders and/or corneal wound healing.

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    Holly, F. J.Lemp, M. A

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