Muscarinic acetylcholine receptor subtypes in human corneal epithelium and endothelium.

BACKGROUND

Muscarinic acetylcholine receptors are located throughout the body. The demonstration of muscarinic receptors in corneal tissue has been inconsistent. Using freshly fixed human corneal tissue, we show a complete profile of muscarinic receptor subtypes in human corneal epithelium and endothelium.

METHODS

Muscarinic receptor sites were studied using immunocytochemistry, immunofluorescence and immunoblotting.

RESULTS

Antibodies to M2, M4 and M5 muscarinic receptor subtypes bound in human corneal epithelium and endothelium. No binding was found for antibodies to M1 and M3 muscarinic receptor subtypes.

CONCLUSIONS

Our studies indicate the presence of M2, M4 and M5 muscarinic acetylcholine receptor subtypes in human corneal epithelium and endothelium. These receptors may play a role in the regulation of corneal homeostasis, other functions, like wound healing, or the pathogenesis of corneal diseases.