Distribution of immunoreactive dynorphin A1-8 in discrete nuclei of the rat brain: comparison with dynorphin A.
The distribution of immunoreactive (ir)-dynorphin A1-8 (Dyn A1-8) in 78 microdissected rat brain areas as well as in the neurointermediate lobe of pituitary gland was determined using a highly specific radioimmunoassay. The highest concentrations of Dyn A1-8 in brain were found in substantia nigra (673.8 fmol/mg protein) and lateral preoptic area (565.1 fmol/mg protein). High concentrations of ir-Dyn A1-8 (greater than 240 fmol/mg protein) were found in 5 nuclei: ventral premamillary nucleus, anterior hypothalamic nucleus, dorsomedial nucleus, arcuate nucleus, and medullary reticular nuclei. Moderate concentrations of the peptide (between 120 and 240 fmol/mg protein) were found in 55 brain nuclei such as septal and amygdaloid nuclei, most diencephalic structures, mesencephalic nuclei, pons and medulla oblongata nuclei and others. Low concentrations of ir-Dyn A1-8 (less than 120 fmol/mg protein) were found in 16 regions, e.g. frontal cortex, hippocampus, caudate-putamen cortical amygdaloid nucleus, several thalamic nuclei, mamillary body superior and inferior colliculi, cerebellar nuclei and others. The posterior thalamic nucleus has the lowest ir-Dyn A1-8 concentration (62.0 fmol/mg protein). The neurointermediate lobe of the pituitary gland is extremely rich in ir-Dyn A1-8 (4063.0 fmol/mg protein).
D000818:Animals; D001921:Brain / Q000378:metabolism*; D004027:Diencephalon / Q000378:metabolism; D004399:Dynorphins; D004723:Endorphins / Q000378:metabolism*; D007031:Hypothalamus / Q000378:metabolism; D008297:Male; D010446:Peptide Fragments / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013687:Telencephalon / Q000378:metabolism
D004723:Endorphins; D010446:Peptide Fragments; D004399:Dynorphins; C026770:dynorphin (1-8)