Table 2.
Putative receptors for UTP in the human heart.
| Receptor | Agonist | Antagonist | Human UTP effect antagonist action | UTP in KO mice |
|---|---|---|---|---|
| P2X1 | ATP | PPADS (good), suramin (good) | - | |
| P2X2 | ATP | PPADS (good), suramin (good) | - | |
| P2X3 | ATP | PPADS (good), suramin (good) | - | |
| P2X4 | ATP | PPADS (poor), | ? | |
| P2X5 | ATP | PPADS (good), suramin (good) | - | |
| P2X6 | ATP | PPADS (poor) | ? | |
| P2X7 | ATP | PPADS (poor) | ? | |
| P2Y1 | ATP | PPADS (good), RB2 (good), suramin (good) | - | |
| P2Y2 | UTP, ATP | RB2 (poor), suramin (good) AR-C1118925a |
- | - |
| P2Y4 | UTP, ATP | PPADS (poor), PSB-1454 (good) |
- | - |
| P2Y6 | UTP, UDP | PPADS (poor), suramin (poor) MRS2578 (good) |
- | - |
| P2Y11 | ATP, UTP | RB2 (good), suramin (good) | - | |
| P2Y12 | ADP | RB2 (good), suramin (good) | - | |
| P2Y13 | ADP | PPADS (poor), RB2 (good), suramin (good) | - | |
| P2Y14 | UDP-glucose | - | ||
| CystLT1R | UDP | - | ||
| CystLT2R | UDP | - |
[33, 30, 52, 53, 54]: no or negligible contractile effect in isolated electrically driven trabeculae 21, 3: carneae from human right atrium. It is apparent that presently only negative reports (-), indicating lack of identification of underlying receptor for PIE of UTP in the human heart is available. A question mark indicates that no clearcut published information is to be found in the literature.