<prompt> Opioid secreted from anterior pituitary?b endorphinGHACTHMSH  <response>: A b endorphin Pro-opiomelanocortin, a large precursor molecule found in anterior and intermediate lobes of pituitary gland and brain, contains b-endorphin, a polypeptide of 31 AA residues, that has met enkephalin at its amino terminal. There are separate enkephalin secreting and fi-endorphin secreting systems of neurons in brain. b-endorphin is also secreted into the bloodstream by pituitary gland. 