PHRM30002 Lecture Notes - Lecture 10: Posterior Pituitary, Naloxone, Endorphins
13 Sep 2018
School
Department
Course
Professor
Document Summary
Np: small proteins or polypeptides with nt-like roles. Diverse roles: pain and analgesia, sleep, emotion, feeding, learning and memory, eg. Synthesis, storage, release and inactivation different to classical nts. 1 gene can result in a number of peptides with diverse roles. Secreted into blood by neurones (hormones) (oxytocin & vasopressin: secreted by endocrine gland (acth, gh) Act within a peripheral organ such as the git (cck) Pro-hormone pro-hormone convertase 1/ 2 -msh, -end, -lph, -msh. Tissue specific proteolytic cleavage: pc1, pc2, exopeptidase. N-terminal acetylation: increase -msh biological activity, decrease -end. Large dense core vesicles (ldcv) golgi apparatus. Need a longer duration of ca2+ to release. Proteolytically cleaved by enzyme located on extracellular membranes (endo- and exopeptidase) Can diffuse further than nt as metabolised extracellularly. Small interact with multiple sites on r. Short duration due to rapid degradation: hydrolysis by peptidases. This level of complexity leads to difficulties to design safe and effective drugs.
