MET-ENKEPHALIN-LIKE IMMUNOREACTIVITY IN A CEPHALOPOD NEUROHEMAL ORGAN

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-α-MSH, ACTH, β-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. © 1979.