The exogenous opioid peptides and DPPIV serum activity in infants with apnoea expressed as apparent life threatening events (ALTE).

Casein-derived peptides have been suggested to play a role in sudden infant death syndrome (SIDS). In this study, we have determined the content of bovine β-casomorphin-7 (bBCM-7) and the activity of dipeptidyl peptidase-IV (DPPIV) in sera of infants with apparent life threatening events (ALTE syndromes, 'near miss SIDS'). We have found that the sera of some infants after an apnoea event contained more β-casomorphin-7 than that of the healthy infants in the same age. In all the children after an apnoea event, however, a lowered DPPIV was detected. We suspect that the low activity of that peptidase may be responsible for opioid-induced respiratory depression, induced by bBCM-7 in the general circulation.