From
proglucagon, at least six final biologically active
peptides are produced by tissue-specific post-translational processing. While
glucagon and
GLP-1 are the subject of permanent studies, the four others are usually left in the shadow, in spite of their large
biological interest. The present review is devoted to
oxyntomodulin and
miniglucagon, not forgetting
glicentin, although much less is known about it.
Oxyntomodulin (OXM) and
glicentin are regulators of gastric acid and hydromineral intestinal secretions. OXM is also deeply involved in the control of food intake and energy expenditure, properties that make this
peptide a credible treatment of
obesity if the question of administration is solved, as for any
peptide.
Miniglucagon, the C-terminal undecapeptide of
glucagon which results from a secondary processing of original nature, displays properties antagonistic to that of the mother-
hormone glucagon: (a) it inhibits
glucose-,
glucagon- and GLP-1-stimulated
insulin release at sub-picomolar concentrations, (b) it reduces the in vivo
insulin response to
glucose with no change in glycemia, (c) it displays
insulin-like properties at the cellular level using only a part of the pathway used by
insulin, making it a good basis for developing a pharmacological workaround of
insulin resistance.