title: Distribution and characterization of synenkephalin immunoreactivity in the bovine brain and pituitary.
abstract: The distribution of synenkephalin, the N-terminal fragment of proenkephalin, was studied in various parts of the bovine brain (globus pallidus, caudate nucleus, hypothalamus) and in the posterior pituitary by the use of a radioimmunoassay. The distribution of synenkephalin-immunoreactivity (IR) was compared to the distribution of Met-enkephalin-IR. Gel exclusion chromatography was used to examine the molecular forms of the immunoreactivities present in the tissues. The distribution of synenkephalin-IR was similar to the distribution of Met-enkephalin-IR, with a molar ratio of Met-enkephalin/synenkephalin ranging between 2.7 and 5.9. In all regions tested except the hypothalamus the synenkephalin-IR was present as a single species. However, in the hypothalamus a small amount of IR material (3% of the total synenkephalin-IR) was detected in fractions where larger Met-enkephalin-containing peptides eluted. Based on the concordance between the molar ratio of Met-enkephalin to synenkephalin found in the tissues and the molar ratio present in the sequence of adrenal proenkephalin, it is concluded that the brain and adrenal glands utilize a similar precursor for enkephalin biosynthesis.
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D002417:Cattle; D002421:Caudate Nucleus / Q000032:analysis; D002850:Chromatography, Gel; D004744:Enkephalin, Methionine / Q000032:analysis; D004745:Enkephalins / Q000032:analysis* / Q000096:biosynthesis; D005917:Globus Pallidus / Q000032:analysis; D007031:Hypothalamus / Q000032:analysis; D010904:Pituitary Gland, Posterior / Q000032:analysis*; D011498:Protein Precursors / Q000032:analysis*; D011863:Radioimmunoassay
chemical_list: D004745:Enkephalins; D011498:Protein Precursors; D004744:Enkephalin, Methionine; C036693:synenkephalin