Caerulein treatment of Parkinson's disease

In view of evidence linking cholecystokinin-containing neurons with both dopamine system function and Parkinson's disease pathophysiology, the therapeutic effects of the cholecystokinin analog, caerulein, were evaluated in 10 parkinsonian patients stabilized on L-Dopa therapy. Despite substantially elevated plasma caerulein levels immediately following intramuscular injection of this peptide, no consistent change in neurologic status could be discerned. These negative results may be due to the relatively small amounts of caerulein entering the CNS at dose levels that do not induce gastrointestinal toxicity.