Neurotensin is a 13 amino acid peptide primarily expressed in the CNS and gastrointestinal tract.
Neurotensin binds to three different receptors: neurotensin receptor 1 and 2 which are G-protein coupled receptors, and neurotensin receptor 3, which is non-G-protein coupled receptors and is also known as sortilin-1 (SORT1).
Peripheral secretion of neurotensin is stimulated by food intake.
Secretion of neurotensin is particularly stimulated by fat and is known to regulate G.I. motility and pancreatic and biliary secretions as well.
In obese individuals as compared with normal weight humans, postprandial plasma neurotensin levels are reduced following a liquid fatty meal and increased at the gastric bypass surgery.
The above suggests that the regulation of neurotensin secretion is disturbed in obesity.
Neurotensin has trophic effects on normal and neoplastic tissue and neurotensin and neurotensin one receptor are suggested to be prognostic tumor markers.
Neurotensin and neurotensin receptor 1 is common in breast cancer tumors.
Genetic variation in one of the three receptors for neurotensin, neurotensin receptor 3, is linked to the development of coronary artery disease and its effects are mediated by elevated levels of LDL-C.
Proneurotensin is a stable N-terminal fragment of the precursor of satiety hormone neurotransmitter.
Fasting proneurotensin is significantly associated with the development of diabetes, cardiovascular disease, breast cancer and with total and cardiovascular mortality (Melander O et al).
Relationship between proneurotensin and morbidity and mortality is significant only for women, as estradiol estradiol up regulates neurotransmitter.