title: Met-enkephaline-like immunoreactivity in a cephalopod neurohemal organ.
abstract: Using a highly specific antibody we found Met-enkephalin-like immunoreactivity in large granules of numerous distinct cells that are embedded in a layer of secretory terminals inside the octopus vena cava. Application of antibodies against fragments of the mammalian pro-opiocortin precursor -- alpha-MSH, ACTH, beta-endorphin and 16k-fragment -- and against growth hormone did not produce immunostaining in the octopus enkephalin cells. The vena cava neuropil may represent a favourable system for the examination of the physiological role of the opioid peptide enkephalin.
mesh_terms: D000818:Animals; D004723:Endorphins / Q000378:metabolism*; D004745:Enkephalins / Q000378:metabolism*; D007124:Immunoenzyme Techniques; D008854:Microscopy, Electron; D009490:Neurosecretory Systems / Q000378:metabolism* / Q000648:ultrastructure; D049831:Octopodiformes / Q000378:metabolism*
chemical_list: D004723:Endorphins; D004745:Enkephalins