PTH stimulates bone resorption by osteoclasts, but it does so indirectly. Receptors for PTH are located on osteoblasts, which then signal to bone marrow-derived osteoclast precursors to stimulate their fusion, differentiation and activation.TH stimulates the generation of new osteoclasts (osteoclastogenesis). After osteoclasts form, the first step necessary for bone resorption to occur is that the mature osteoclast needs to tightly adhere to the bone, creating a specialized isolated compartment.