**Abstract**

ATP acting via different subtypes of P2X and P2Y receptors induces contractions or relaxation of mammalian smooth muscles, while in skeletal muscles, ATP can pre- and postsynaptically modulate effect of acetylcholine. It was shown that effects of ATP on both types of the muscle are significantly changed when the temperature shifts from physiological condition. For example, contractile responses of rodent urinary bladder and vas deferens mediated by P2X receptors are markedly increased with the decrease of the temperature. Similarly, in frog skeletal muscles, ATP-induced inhibition of acetylcholine release became more pronounced at low temperatures. In case of mammalian skeletal muscle, effect of temperature on ATPinduced responses depends on the type of muscle—slow and fast. In this chapter, we will discuss temperature-dependent effects of ATP on different muscle contractility and their possible mechanisms.

**Keywords:** ATP, P2 receptors, temperature, hypothermia, smooth muscles, skeletal muscles, contractility, neuromuscular synapse
