Abstract
PURPOSE: Purinergic receptors play a key role in the function of the lacrimal gland (LG) as P1 purinergic receptors A(1), A(2A), and A(2B), P2X(1-7) receptors, and many of the P2Y receptors are expressed. METHODS: This review examines the current knowledge of purinergic receptors in the LG as well as the signaling pathways activated by these receptors. RESULTS: These receptors are expressed on the acinar, ductal, and myoepithelial cells. Considerable crosstalk exists between the pathways activated by P2X(7) receptors with those activated by M(3) muscarinic or α(1D) adrenergic receptors. The mechanism of the crosstalk between P2X(7) and M(3) muscarinic receptors differs from that of the crosstalk between P2X(7) and α(1D) adrenergic receptors. CONCLUSIONS: Understanding purinergic receptors and how they modulate protein secretion could play a key role in normal and pathological responses of the LG.