Characterization of N alpha-acetyl-alpha-endorphin from rat neurointermediate lobe and its distribution in pituitary and brain.
N alpha-Acetyl-alpha-endorphin was characterized from rat neurointermediate lobe. The distribution of the acetylated and the non-acetylated form of alpha-endorphin in dissected areas of pituitary and brain appeared to be uneven. alpha-Endorphin appeared to be the main peptide in the anterior pituitary, whereas in the neurointermediate lobe N alpha-acetyl-alpha-endorphin accounted for most of the alpha-endorphin immunoreactivity. In the brain, the highest concentration of alpha-endorphin immunoreactivity was found in the hypothalamus. In hypothalamus and thalamus alpha-endorphin predominated, whereas in amygdala, hippocampus and septum N alpha-acetyl-alpha-endorphin represented most of the alpha-endorphin-immunoreactivity. In view of the non-opioid properties of acetylated endorphins, it is suggested that acetylation represents a mechanism allowing the organism to specifically select the non-opioid behavioral activities enclosed in the endorphin sequence.
D000818:Animals; D001923:Brain Chemistry; D002851:Chromatography, High Pressure Liquid; D004723:Endorphins / Q000302:isolation & purification*; D008297:Male; D010902:Pituitary Gland / Q000032:analysis*; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains
D004723:Endorphins; C040082:N-acetyl-alpha-endorphin