9306921 Bloomfield This research planning grant for women supports studies exploring the potential role of insulin-like growth factor II (IGF-II) in mediating the response of bone to changes in mechanical strain. Previous investigators have developed valuable animal models to quantify and describe in detail the nature of the bony response to increases in loading experienced by bone, as well as to the decreased loading of various immobilization treatments. Little is known, however, about cellular or molecular mechanisms for the subsequent gain or loss in bone volume routinely observed with these conditions. Specifically, how do bone cells perceive strain and then transduce that mechanical signal to a biochemical factor which then initiates increases in bone formation activity (in the case of increased loading) or suppresses formation in favor of resorption (in the case of decreased loading)? The planning activities of this proposal will provide training in two primary tools essential to this line of research: bone histomorphometry and molecular biology techniques to isolate and quantify mRNA for IGFs from bone tissue. ***
