Humatrope (somatropin, rDNA origin, for injection) is a polypeptide hormone of recombinant DNA origin. Humatrope is synthesized in a strain of Escherichia coli that has been modified by the addition of the gene for human GH. The peptide is comprised of 191 amino acid residues and has a molecular weight of about 22,125 daltons. The amino acid sequence of the peptide is identical to that of human GH of pituitary origin. Somatropin is a form of human growth hormone important for the growth of bones and muscles. Somatropin is also used in adults to treat short bowel syndrome, or to prevent severe weight loss related to AIDS.