GDNF is expressed in two forms in many tissues outside the CNS.

A recently cloned neurotrophic factor, Glial Cell Line-Derived Neurotrophic Factor (GDNF), has been implicated in the survival and morphological and functional differentiation of midbrain dopaminergic neurones in vitro. GDNF has therefore been proposed as a factor which may have utility in the treatment of Parkinson's disease. In the present study, we have used RT-PCR to analyse the distribution of GDNF mRNA throughout the newborn rat (P0). We show that GDNF transcripts are present in kidney, lung, bone, heart, liver, spleen, sciatic nerve and blood. Two separate GDNF transcripts are present in different ratios in each tissue investigated. Sequence analysis of both these mRNA species revealed that the shorter transcript (sGDNF) contains a deletion of 78 bp in comparison to the published sequence for GDNF. We speculate that this shorter mRNA arose due to alternative splicing.