Presence of helodermin-like peptides of the VIP-secretin family in mammalian salivary glands and saliva.

Helodermin is a biologically active peptide isolated from the venom of the Gila monster lizard (Heloderma suspectum) whose structure is related to that of vasoactive intestinal peptide and secretin. Using a specific radioimmunoassay based on antisera prepared by immunizing rabbits with natural helodermin, we demonstrated the presence of helodermin-like material in mammalian salivary glands, including parotid, submaxillary and sublingual glands from rat and dog, and parotid and submaxillary glands from man. All helodermin-like materials had an apparent molecular mass of 4-12 kDa. Dog saliva, collected after pilocarpine stimulation, revealed similar immunoreactivity with a major component around 6 kDa.