Animals have rapid body growth in early life stages, then the body impose limits to itself. From a single stem cell, several differente tissues (hearth, skin, eyes…) differentiate and acquire differente functions.

WHY… What promotes differentiation? Stimulus or inhibitiors? 

Recent studies and (Julian C. et al, 2011) provide insight into a long-standing this mystery of biology.

So until now, we know that here are several mechanisms involved. This mechanisms act locally and not in a systemic way. Of course that behind this control there is a genetic map where the inhibitor information is primarly imprinted. So there are several genes that are responsible for new proteins once expressed in tissues, limit the growth.

In my study, i looked for hearth and muscle growth… Imagine  that skeletal and cardiac muscle growth are negatively regulated by myostatin and the concentration  depends on muscle mass itself. Liver growth appears to be modulated by bile acid flux, a parameter that reflects organ function. In pancreas, organ size appears to be limited by the initial number of progenitor cells, suggesting a mechanism based on cell-cycle counting. Further elucidation of the fundamental mechanisms suppressing juvenile growth is likely to yield important insights into the pathophysiology of childhood growth disorders and of the unrestrained growth of cancer.

In addition, improved understanding of these growth-suppressing mechanisms may someday allow their therapy.

Growth-suppressing mechanisms may someday allow their therapeutic suspension. Maybe, in HAP we will be able to stop Smooth muscle cells to proliferate in vessels.

Ester