ABSTRACT
A variety of hormones and nutrients promote muscle growth though this anabolic drive may be compromised by illness, injury, or aging. Anabolic dysfunction arises from resistance to the effects of anabolic hormones (e.g., growth hormone and insulin) and nutrients during ill health. There may also be a shift in the secretion of catabolic vs. anabolic hormones during illness so as to favor weight loss. Bioactive peptides for combating weight loss due to anabolic dysfunction are described in this chapter. Changes in levels of hormones that contribute to anabolic dysfunction are summarized in Section 8.1. The effects of insulin, growth hormone, and IGF-1 in promoting muscle gain are discussed in Sections 8.2 and 8.3; this is followed by a discussion of the synthetic bioactive peptides that promote growth hormone secretion in Section 8.4. Ghrelin, the rst natural growth hormone secretagogue, is discussed in Section 8.5. Finally, in vivo applications and human clinical trial data related to the use of bioactive peptides to promote muscle growth are reviewed in Section 8.6.
