Microdialysis measurement of in vivo neuropeptide release

The application of the microdialysis sampling technique for in vivo measurement of neuropeptide release is discussed. In vitro recoveries of different microdialysis membranes are described for a variety of neuropeptides (ranging from 400 to 4500 MW) as well as their dynamic potential for measuring external concentration changes. In vivo experiments illustrating the use of the technique for measuring release of oxytocin and met-enkephalin from the brain of the conscious sheep, and vasopressin in the blood of the anaesthetised rat are described.