Successful ventricular application of the miniaturized controlled-delivery Accurel technique for sustained enhancement of cerebrospinal fluid peptide levels in the rat.

A recently developed small controlled-delivery peptide device has now been further miniaturized (3.5 mm3 rod) and its action has been tested in vitro and in vivo using vasopressin (VP) as experimental substance. In vitro immersion showed a constant and lasting release of VP for weeks, as had been described for larger devices. By introducing the mini-device into the lateral ventricle of rat brain and by sampling CSF via a permanent cannula in the cisterna magna, a steadily enhanced level of VP could be attained for CSF. These increased levels persisted for one week, but most likely continue for longer periods.