In addition to the primary function chromogranins in granulogenesis of vesicle formation, CgA is the precursor for many functional peptides such as vasostatin, pancreastatin
, catestatin, parastatin, serpenin, and other peptides that have many physiological functions (including autocrine, paracrine, and endocrine) in the corresponding neuroendocrine physiology.
15) Pancreastatin, a split product of chromogranin A, is another serum biomarker that may be elevated in up to 81% of patients with carcinoid tumors.
Serum pancreastatin levels predict response to hepatic artery chemoembolization and somatostatin analogue therapy in metastatic neuroendocrine tumors.
induces apoptosis and autophagy in metastatic prostate cancer cells.
Gonzalez-Yanes C, Sanchez-Margalet V Pancreastatin
, a chromogranin A-derived peptide, inhibits leptin and enhances UCP-2 expression in isolated rat adipocytes.
The CgA([left arrow]301) assay (using antibody 871w-1) is specific for the amidated C-terminus of pancreastatin (16).
In a similar study, plasma CgA was quantified with an RIA using an antiserum raised against C-terminal CgA fragments isolated from urine from a carcinoid tumor patient and a pancreastatin antiserum, respectively, and increased concentrations were measured in 99% with the CgA assay and in 46% with the pancreastatin assay (32).
The primary structure of human chromogranin A and pancreastatin.
Characterization of immunoreactive pancreastatin in porcine tissues.
Immunoreactive pancreastatin [CgA(273-301) amide] was measured by RIA using antiserum 871w-1, specific for the amidated COON terminus of pancreastatin, as detailed elsewhere (21).
Lower concentrations were measured using antisera specific for the N-terminal epitope of CgA and the pancreastatin antiserum.
In agreement with our results, pancreastatin concentrations in extracts of human antral mucosa and pancreas have been reported to range from 0.