Human gastric inhibitory polypeptide (GIP) is a 42-amino-acid peptide belonging to the glucagon-secretin family of peptide hormones. GIP is secreted by endocrine cells in the duodenal mucosa and stimulates glucose-dependent insulin secretion as well as GLP-1 release from more distal endocrine (L) cells in the intestinal mucosa. GIP shows amino-acid sequence similarities to glucagon, GLP-1 and GLP-2 (from approximately 50% identity for glucagon to 30% identity for GLP-2).
Endothelins are endothelium-derived vasoconstrictor peptides. Endothelin-1 (ET-1) is expressed in lung, placental stem villi vessels and in cultured placental vascular smooth muscle cells. Endothelin-1 is expressed as a 212-aa precursor (preproendothelin-1) that is sequentially cleaved into 2 chains: Endothelin-1 (21 aa) and Big Endothelin-1 (38 aa). This antibody recognizes an epitope in the N-term prodomain of Endothelin-1.
Adrenomedullin (AM) is a potent hypotensive and vasodilatator agent found in human pheochromocytoma. AM inhibits basal ACTH secretion. The hormone precursor called preproadrenomedullin, is a 185-aa protein whereas the mature form is 52-aa long.