the effects of deprenyl on p75 receptor mrna changes in new born rats after sciatic nerve axotomy

introduction: neurotrophins belong to growth factor family and their function is based on their receptors. they bind two types of receptors: p75 and tyrosine kinase. the motoneuron survival or death depends upon the neurotrophic factors. recent studies have demonstrated that axotomy in peripheral nerve induces apoptosis of motoneuron. deprenyl or selegiline is known as a drug with neuroprotective effect on motoneurons. in this investigation, we evaluated mrna changes in p75 receptor by anti-apoptic effect of deprenyl in motoneuron death induced by axotomy of rat sciatic nerve. methods: the left sciatic nerves of sprague-dawley newborn 3 days old rats, were axotomized in the middle of thigh. the newborn rats were divided into two groups one group was treated with intra peritoneal injection of 2.5 mg/kg deprenyl (treated) and the other group with normal saline (untreated). each group was divided to 3 sub groups as, the first was treated with 2.5 mg/kg deprenyl or normal saline one hour before surgical transection, the second and third were treated at, and one hour after surgery, respectively. molecular studies for mrna changes trk-b and p75ntr receptor were done on two groups of animals which were sacrificed 4 hours after injection and other one, 24 hours after injection. results: the rt-pcr revealed that deprenyl has reduced the mrna p75 after 24 hours. conclusion: deprenyl can maintain motoneurons by reducing mrna p75 receptor.