Inositol - An effective growth promotor?

Inositol is a naturally occurring sugar-alcohol present in plants and animals, either in its free form, as a phospholipid component or as inositol phosphate (IP) esters. Dietary inositol is readily absorbed from the intestine via SMIT1 with levels being detectable in the blood as well as in various tissues. Recent studies have revealed a potential link between free inositol content and improved growth response in animals. There is limited data suggesting why an increase in inositol would result in improved growth; however, it would appear that inositol has numerous biological functions within the body. A number of tissues are capable of synthesising this polyol from glucose, although the kidney appears to be the primary site of catabolism. Studies investigating the effect of inositol deficiencies in various animal species have revealed a number of biological processes that are reliant on inositol to function. One of inositol's main functions appears to be its involvement as a phospholipid component of cell membranes and lipoproteins. Cell signalling pathways involving phosphoinositide phospholipids, such as the IP3/DAG and IGF/PIK/Akt pathways, lead to a number of cellular responses that are important for cell survival and growth. On a larger scale, inositol appears to be essential for both prenatal and postnatal development of peripheral nerves, CNS and bone. With regards to a potential growth response, upregulation of specific signalling pathways, such as the IGF/Akt/mTOR pathway, in the skeletal muscle has been shown in response to phytase supplementation and the consequential increase in free inositol. These signalling pathways are responsible for protein synthesis and increased glucose absorption in this tissue. Since inositol has also been shown to be an important regulator of the transport and deposition of fat, it may be possible to use inositol to support the growth of a lean animal.