ABSTRACT
Glial cell line-derived neurotrophic factor (GDNF) is a potent neurotrophic factor involved in the survival and proliferation of neurons. However, there have been few reports examining the relationship between GDNF and functional recovery after cerebral infarction. The authors investigated the change in the expression of GDNF proteins during functional recovery in rats following photochemically induced cerebral infarctions. Functional recovery for the first 14 days after the infarction was evaluated using a beam-walking test. The number of GDNF-like immunoreactive cells around the infarction were counted at various times (24 h, 72 h, 7 days, and 14 days) post-infarction. Immunohistochemical analysis of brain sections showed that the expression of GDNF-like immunoreactive cells was significantly increased in the temporal cortex until 7 days on the side ipsilateral to the infarction, and had decreased by 14 days. Likewise, the functional recovery of paralysis was substantial until 7 days post-infarction, after which the improvement was mild. Therefore, the expression of GDNF protein might have some relationship with the functional recovery of paralysis. There are great hopes that GDNF could be used as a therapeutic agent for cerebral infarction.
Subject(s)
Cerebral Infarction/metabolism , Cerebral Infarction/physiopathology , Glial Cell Line-Derived Neurotrophic Factor/metabolism , Recovery of Function/physiology , Analysis of Variance , Animals , Cell Count , Cerebral Infarction/chemically induced , Gene Expression Regulation/physiology , Immunohistochemistry/methods , Photochemistry/methods , Psychomotor Performance/physiology , Rats , Rats, Wistar , Rose Bengal , Time FactorsABSTRACT
OBJECTIVE: To investigate the effect of repetitive passive stretch of living rat muscle on myogenin messenger ribonucleic acid (mRNA) expression. DESIGN: Case-controlled study. SETTING: University laboratory. ANIMALS: Seventeen female 8-week-old Wistar rats. INTERVENTIONS: Repetitive stretch (15 times/min) was performed manually on gastrocnemius muscle of anesthetized rats for 15, 30, and 60 minutes. MAIN OUTCOME MEASURES: Total RNA was extracted, after the animals were killed, from the gastrocnemius muscle, and Northern blotting was performed using oligonucleotide complementary to myogenin. RESULTS: Repetitive stretch to gastrocnemius muscles of anesthetized rats for 1 hour induced a 21.5% increase in the expression of myogenin mRNA. CONCLUSIONS: Repetitive passive stretch of the rat skeletal muscle for 60 minutes induced the expression of myogenic transcription factor myogenin mRNA. These findings suggest the clinical utility of passive repetitive stretch to maintain muscle strength in patients who are unconscious or paralyzed.
