GDNF was not intracerebrally detected by immunohistochemistry or ELISA methods.

<p>(A to C) Coronal images of GDNF immunostained striatal sections of vehicle (A), 1 mg/kg (B), and 5 mg/kg (C) HIRmAb-GDNF treatments. *Inset in (A) corresponds to a positive control tissue stained in parallel from a monkey that received intracerebral injections of human neuroprogenitor cells expressing GDNF. Scale bar: 1 mm. (D and E) ELISA determination of GDNF levels in the brain (D) and in the pancreas (E).