['Abnormal intravesical pressure results in a series of pathological changes. We investigated the effects of hydrostatic pressure and muscarinic receptors on the release of inflammatory cytokines in rat and human bladder smooth muscle cells (HBSMCs).', 'Animal model of bladder outlet obstruction was induced by urethra ligation. HBSMCs were subjected to elevated hydrostatic pressure and/or acetylcholine (Ach). Macrophage infiltration in the bladder wall was determined by immunohistochemical staining. The expression of inflammatory genes was measured by RT-PCR, ELISA and immunofluorescence.', 'In obstructed bladder, inflammatory genes and macrophage infiltration were remarkably induced. When HBSMCs were subjected to 200-300\u2009cm H'] Are hydrostatic pressure and muscarinic receptors involved in the release of inflammatory cytokines in human bladder smooth muscle cells?