Title: Insulin-like Growth Factors
Synonyms: IGFs
Literature References: Family of conserved peptide hormones structurally homologous with insulin. Two major circulating forms mediate the growth promoting effects of somatotropin,
q.v. IGF-I regulates both prenatal and postnatal growth; IGF-II is a key factor in fetal development. IGFs are produced primarily in the liver under the regulation of growth hormone; also produced locally by most tissues. Transported in the serum by
IGF binding proteins (or
IGFBP) that prolong the half-life and regulate the metabolic effects of IGFs. Discovered and termed
sulphation factors because of their ability to stimulate the incorporation of sulfate by cartilage: W. D. Salmon, W. H. Daughaday,
J. Lab. Clin. Med. 49, 825 (1957). These peptides have also been referred to as
NSILA-S, or non-suppressible insulin-like acting substance. The designation
somatomedin was proposed to connote the intermediary relationship to somatotropin: W. H. Daughaday
et al., Nature 235, 107 (1972). Discussion of nomenclature:
idem et al., J. Clin. Endocrinol. Metab. 65, 1075 (1987). Isoln, chemical characterization, biological properties of IGF-I and IGF-II: E. Rinderknecht, R. E. Humbel,
Proc. Natl. Acad. Sci. USA 73, 2365, 4379 (1976). Amino acid sequence of IGF-I:
eidem, J. Biol. Chem. 253, 2769 (1978); of IGF-II:
eidem, FEBS Lett. 89, 283 (1978). Total synthesis of human IGF-I: C. H. Li
et al., Proc. Natl. Acad. Sci. USA 80, 2216 (1983); of human IGF-II:
eidem, Biochem. Biophys. Res. Commun. 127, 420 (1985). Review of molecular biology: W. H. Daughaday, P. Rotwein,
Endocr. Rev. 10, 68-91 (1989); of mechanism of action: A. Spagnoli, R. C. Rosenfeld,
Endocrinol. Metab. Clin. North Am. 25, 615-631 (1996). Review of IGF binding proteins: D. R. Clemmons,
Cytokine Growth Factor Rev. 8, 45-62 (1997).
Reviews: C. E. H. Stewart, P. Rotwein,
Physiol. Rev. 76, 1005-1026 (1996); D. Le Roith,
N. Engl. J. Med. 336, 633-640 (1997).
Derivative Type: Insulin-like Growth Factor I
CAS Registry Number: 67763-96-6
Synonyms: IGF-I; somatomedin 1; somatomedin C; SM-C
Literature References: Single chain, basic protein containing 70 amino acid residues. Review of physiology and potential therapeutic uses: E. R. Froesch
et al., Diabetes Metab. Rev. 12, 195-215 (1996).
Derivative Type: Insulin-like Growth Factor II
CAS Registry Number: 67763-97-7
Synonyms: IGF-II; multiplication-stimulating activity III-2; MSA III-2
Properties: Single chain, slightly acidic protein containing 66 or 67 amino acid residues depending on the species.
Derivative Type: Mecasermin
CAS Registry Number: 68562-41-4
Synonyms: Human insulin-like growth factor I
Molecular Formula: C331H512N94O101S7
Molecular Weight: 7648.63
Percent Composition: C 51.98%, H 6.75%, N 17.21%, O 21.13%, S 2.93%
Literature References: Myotrophin (Cephalon) and
Somason (Fujisawa) are recombinant products. Clinical trial in amyotrophic lateral sclerosis: D. J. Lange
et al., Neurology 47, Suppl. 2, S93 (1996).
Therap-Cat: In treatment of growth hormone insensitivity syndrome and insulin resistance.