Neurotensin may play an endocrine or paracrine role in the regulation of fat metabolism. It causes contraction of smooth muscle. Interacts with NTSR1 (PubMed:23140271). Interacts with SORT1 (PubMed:19122660). Interacts with SORL1 (PubMed:11294867). Packaged within secretory vesicles. Neurotensin is cleaved and degraded by Angiotensin-converting enzyme (ACE) and neprilysin (MME). Belongs to the neurotensin family. Neurotensin entry