A middle aged man noticed that he can no longer fit in his shoes and that his jaw was protruding and phalanges were enlarged. These effects are likely to be mediated by.

Answer is B (Somatomedins): Many of the physiological affects of Growth Hormone are mediated indirectly through somatomedins like IGF-1 (Insulin like Growth fbactor) which is a potent growth and differentiation factor. Increased shoe size, Prognathism (protruding jaw) and enlarged phalanges in a middle aged man suggest a diagnosis of Growth Hormone oversecretion or Acromegaly. Growth Hormone exes several effects through induction of somatomedins (like IGF), a family of hormones secreted in the blood by the liver and other tissues. What are Somatomedins Somatomedins arc a family of harmones that are potent growth and differentiation factors. The liver is the major source of somatomedins like IGF-1 that mediates many of the physiological effects of Growth Hormone on target tissues. Somatomedins are similar to insulin in molecular structure and are hence also known as 'Insulin like Growth factors' (IGF) and these act on target tissue to increase protein synthesis by increasing the rate of uptake of amino acids. Although GH exes direct effects on target tissues, many of its physiological effects are mediated indirectly through somatomedins like IGF-1