title: Characterisation of Met-enkephalin(Arg6,Phe7) immunoreactivity in human adrenal and human phaeochromocytoma.
abstract: The molecular forms of opioid peptides in human adrenal have not been well characterised. These peptides are predominantly derived from the proenkephalin A precursor, which has the sequence of Met-enkephalin(Arg6,Phe7) as its carboxyl terminus. We have looked in the present study at the subcellular distribution and the molecular form of immunoreactivity to this sequence in post-mortem human adrenal medulla and in phaeochromocytoma. In the human adrenal homogenates, the immunoreactivity distributes on a sucrose gradient in a manner consistent with localisation in chromaffin granules. On chromatography, the immunoreactivity from adrenal medulla is predominantly in the heptapeptide form; the intermediate (3000-4000) molecular weight material is only a minor component of immunoreactivity, in contrast to bovine tissue extracts where this is the major form of immunoreactivity. In the phaeochromocytoma extracts, the heptapeptide sequence again predominates over a minor amount of intermediate sized material. The results are discussed in terms of post-mortem changes, precursor processing and the function of the adrenal medulla.
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000032:analysis*; D000311:Adrenal Glands / Q000032:analysis*; D000328:Adult; D002395:Catecholamines / Q000032:analysis; D002648:Child; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004744:Enkephalin, Methionine / Q000031:analogs & derivatives* / Q000032:analysis; D006801:Humans; D007106:Immune Sera; D008297:Male; D008875:Middle Aged; D010673:Pheochromocytoma / Q000032:analysis*; D011863:Radioimmunoassay / Q000379:methods; D013347:Subcellular Fractions / Q000032:analysis
chemical_list: D002395:Catecholamines; D007106:Immune Sera; D004744:Enkephalin, Methionine; C027511:enkephalin-Met, Arg(6)-Phe(7)-