Working Towards Control of Muscle Growth
Progressive loss of muscle with age is a problem, and a number of lines of research show promise in engineering a way around that. Here, EureAlert! notes another possible path: "a transient and local rise in an inflammatory signal, the cytokine known as interleukin-6 (IL-6), is essential for the growth of muscle fibers. The findings offer the first clear mechanism for the stem cells' incorporation into muscle and the first evidence linking a cytokine to this process ... As we learn more about how muscles grow in adults, we may uncover new methods for restoring lost muscle mass in the elderly and ill ... IL-6 was produced both within myofibers and in their associated satellite cells, leading to muscle growth. In contrast, the muscles of mice lacking IL-6 did not show any significant increase in size after several weeks of overloading. The researchers also showed that IL-6 exerts its effects by inducing the proliferation of satellite cells. ... Treatments could be designed to compensate for or block the pathways leading to muscle loss. In muscles that have already lost mass, you might also be able to stimulate muscle growth."
Link: http://www.eurekalert.org/pub_releases/2008-01/cp-nii010208.php