Toluidine blue stain; in control rat (A), post HCl treated rat (B), post HCl + LESW (bladder with 0 ml saline) treated rat (C), post HCl + LESW (bladder with 0.2 ml saline) treated rat (D), post HCl + LESW (bladder with 0.4 ml saline) treated rat (E). A large number of mast cells were activated in HCl treated bladder tissue. Mast cell activation (arrow) was shown by toluidine blue staining in the bladder specimen. Mast cell activation is significantly decreased in that with LESW treatment (Magnification ×400, control vs HCl with or without LESW treated rats, ∗∗∗p < 0.001, HCl vs HCl + LESW treated rats, ###p < 0.001).