An apparatus for treating tissue of a mammalian body. In one embodiment, a spring mechanism is carried by first and second tubular members and actuatable for moving a needle from a first position disposed within the distal extremity of the first tubular member to a second position extending distally of the first tubular member. In another embodiment, a nozzle is coupled to the distal extremity of an elongate tubular member for delivering a material into tissue of the mammalian body. In a further embodiment, a flexible elongate member provided with a recess is introduced into a cavity of the body to capture tissue in the recess and electrical energy is applied to such tissue in the recess so as to change the compliance of the tissue.