Oxyntomodulin (OXM)

Oxyntomodulin is a 37 amino acid peptide that contains the 29 amino acid sequence of glucagon followed by an 8 amino acid carboxyterminal extension. Radioimmunoassays using antisera that are not specific for both the C-and N-terminus of oxyntomodulin will also cross-react with glucagon, and possibly glicentin. Hence much of the earlier literature assessing circulating oxyntomodulin using non-specific assays may not be 100% accurate. Oxyntomodulin has also been shown to inhibit food intake following icv administration in rats. Injection of oxyntomodulin directly into the paraventricular nucleus also resulted in reduced food intake. Oxyntomodulin appears to inhibit food intake both prior to the onset of dark phase, as well as in fasted rats in the am. Remarkably, the anorectic actions of oxyntomodulin were blocked by the GLP-1 receptor antagonist exendin (9-39).