Neonatal administration of L-cysteine does not produce long-term effects on neurotransmitter or neuropeptide systems in the rat striatum.
Previous studies by other investigators have shown that neonatal administration of high doses of L-cysteine produces within 6 hrs morphological damage to neurons in many areas of the brain including the striatum; the damage could be blocked by NMDA antagonist MK-801. These studies implicated a potential involvement of this amino acid in neurodegenerative processes including Parkinsonism. The present study attempted to elucidate whether L-cysteine produces long-term changes in neurotransmitter (dopamine; 5-hydroxytryptamine) or neuropeptide (Met5-enkephalin; dynorphin A (1-8); substance P) systems as a corollary to neonatal treatment with L-cysteine. L-cysteine (0.5 or 1 g/kg, s.c.) was administered to 4-day old rat pups and sacrificed 35 days later. The striatal levels of amines and neuropeptides were determined by HPLC and radioimmunoassay respectively. L-Cysteine treatment alone or after a pretreatment with MK-801 (1 mg/kg, s.c.) failed to produce any significant changes in the parameters studied. The results indicate that neonatal administration of L-cysteine does not appear to produce long-term effects on major neuroregulator systems of the striatum.
Department of Pharmacology & Toxicology, Indiana University School of Medicine, Gary 46408.
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D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism*; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D003545:Cysteine / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D009479:Neuropeptides / Q000187:drug effects* / Q000378:metabolism; D018377:Neurotransmitter Agents / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
D009479:Neuropeptides; D018377:Neurotransmitter Agents; D003545:Cysteine