Helodermin-like peptides in noradrenaline cells of adrenal medulla.

Helodermin, a VIP/secretin-like peptide, was first isolated from the venom of the lizard Gila monster. Small amounts of helodermin-like peptides have since been detected in many mammalian tissues. Notably high concentrations were demonstrated in the thyroid gland, and immunocytochemical studies revealed intense helodermin-like immunostaining in thyroid C cells and medullary thyroid carcinoma cells. In the present study, we examined the adrenal gland of mouse, rat and pig for the presence of helodermin-like peptides. Using an antiserum raised against lizard helodermin immunostaining was observed in the noradrenaline-producing cells of the adrenal medulla in all 3 species. Radioimmunoassay revealed high concentrations of helodermin-like peptides in the mouse and rat adrenal. The concentrations in the pig adrenal could not be determined because of a non-parallel dilution curve. Upon high-performance liquid chromatography, the immunoreactive material in extracts of mouse and rat adrenals eluted in one major peak, close to the elution position of lizard helodermin.