Do you have an experience that you cut your finger, it is painful in the few minutes, after that, it stops that feeling. Do you know why? This related a kind of hormone called opioid peptides. Their function is as j nanalgesic hormones. Opioid neuropeptides were first discovered in 1974 by two independent groups of investigators: John Hughes and Hans Kosterlitz of Scotland isolated — from the brain of a pig,called enkephalins.1 Around the same time, in a calf brain, Rabi Simantov and Solomon H. Snyder of the United States found endorphin, what Eric Simon later termed "endorphin" by an abbreviation of "endogenous morphine", meaning "morphine produced naturally in the body".2 This also called lipotropic peptide. This essay will discuss about where the hormones produced, the structure of the hormones and their function.
The pituitary has two parts: anterior pituitary and posterior pituitary. The anterior pituitary produced four peptide and protein hormones. The four peptide hormones are thyroid-stimulating hormone, luteinizing hormone, follicle stimulating hormone and corticotropin. The other hormones are prolactin, growth hormone, enkephalins and endorphins. The enkephalins also have been found in the rostral ventral medulla and in the spinal cord regions.
Enkephalins and endorphins are neuropeptides. Neuropeptide are produced in cells derived from ambryonic neural precursor structures, these include neurons, chromaffin cells of the adrenal medulla, enterochromaffin cellsof the gut and islet cells of the pancreas. The neuropeptides precursors are protein molecules. The protein precursors for each type of peptide are made in the cell body which is the site of almost all protein synthesis in the neuron. The protein is packed into large vesicles with enzymes. These vesicles are transported to the axon terminal and released.
Ref: http://neuroscience.uth.tmc.edu/s1/chapter14.html The neuropeptides have three types: opioid peptides,