Manipulation of vasopressin level in the cerebrospinal fluid of the rat by means of an easily interchangeable controlled-delivery Accurel mini-device.

The procedure described for the continuous release of vasopressin (VP) in the rat lateral ventricle via implantation of a VP-loaded Accurel/collodion mini-device has now been further developed, allowing the introduction, removal and exchange of the Accurel device through a polyethylene guide cannula. In this way, manipulation of the VP level in the cerebrospinal fluid can easily be accomplished. VP levels were measured by radioimmunoassay in liquor withdrawn from the cisterna magna.