The nucleotide receptor P2Y6 binds UDP, and is a member of the G-protein coupled receptor superfamily.P2Y6 agonists induce an inositol phosphate/Ca2+ response that is insensitive to pertussis toxin inhibition. P2Y6 is coupled to phospholipase C via Gq, and is also coupled to inhibition of N-type Ca2+ and M-type K+ channels.P2Y6 mRNA is expressed in various rat tissues, including lung, stomach, intestine, spleen, heart, and aorta. P2Y6 was reported to mediate contractions in human cerebral arteries.