Nerve-evoked purinergic signalling suppresses action potentials, Ca~(2+) flashes and contractility evoked by muscarinic receptor activation in mouse urinary bladder smooth muscle

摘要

Contraction of urinary bladder smooth muscle (UBSM) is caused by the release of ATP and ACh from parasympathetic nerves. Although both purinergic and muscarinic pathways are important to contraction, their relative contributions and signalling mechanisms are not well understood. Here, the contributions of each pathway to urinary bladder contraction and the underlying electrical and Ca~(2+) signalling events were examined in UBSM strips from wild type mice and mice deficient in P2X1 receptors (P2X1~/~) before and after pharmacological inhibition of purinergic and muscarinic receptors.