title: Neuroprotective effect of exogenous melatonin on dopaminergic neurons of the substantia nigra in ovariectomized rats.
abstract: Melatonin has receptors in substantia nigra pars compacta (SNc) and regulates development of dopaminergic (DA) neurons. This study was undertaken to determine ability of melatonin to protect SNc dopaminergic neuron loss induced by estrogen deficiency in ovariectomized rats.
  
  
  
  Female rats were randomized into four groups of seven each: control, ethanol sham, ovariectomy (ovx) and ovx with melatonin (ovx + m). In ovx, ovaries were removed. Ovx + m group was intraperitoneally injected with melatonin for 10 days, while the ethanol sham group received only ethanol. All rats were perfused with 4% paraformaldehyde, midbrains removed, fixed and paraffin embedded, then processed for Nissl and tyrosine hydroxylase staining (IHC). Ten sections of SNc in Nissl and IHC staining were analyzed in each animal, Nissl stained and tyrosine hydroxylase (TH) immunoreactive cells were counted in five experimental groups randomly. Data was analyzed using SPSS by ANOVA and t-test. Differences were considered significant for P<0.05.
  
  
  
  There was less cell number in ovx compared to control and ethanol sham groups significantly (P<0.001). The ovx + m group had more cells than the ovx group in the SNc significantly (P<0.001). Furthermore, there was significant decrease of TH positive cell number in the ovx group compared to control and ethanol sham groups (P<0.05). The number of TH immunoreactive cells was higher in ovx + m compared to the ovx group (P<0.05).
  
  
  
  These findings can be compared with human and used in clinical application for prevention of DA neuron death of SNc after ovariectomy.
authors: Dept. of Anatomy, Tehran University of Medical Sciences, Hemmat Highway, Iran. femehra@yahoo.com
authors: Fereshteh
authors: F
authors: Mehraein
authors: Arak University of Medical Sciences, Arak, Iran.
authors: Reza
authors: R
authors: Talebi
authors: Allied Medicine Faculty, Tehran University of Medical Sciences, Hemmat Highway, Tehran, Iran.
authors: Behnamedin
authors: B
authors: Jameie
authors: Dept. of Anatomy, Tehran University of Medical Sciences, Hemmat Highway, Iran. femehra@yahoo.com
authors: Mohammad Taghi
authors: MT
authors: Joghataie
authors: Dept. of Pathology and Oncopathology Research Center, Medical Faculty, Tehran University of Medical Sciences, Hemmat Highway, Tehran, Iran.
authors: Zahra
authors: Z
authors: Madjd
mesh_terms: D000818:Animals; D002452:Cell Count; D004298:Dopamine / Q000378:metabolism*; D005260:Female; D006801:Humans; D008550:Melatonin / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism*; D018696:Neuroprotective Agents / Q000494:pharmacology*; D009562:Nissl Bodies / Q000187:drug effects / Q000378:metabolism; D010052:Ovariectomy; D051381:Rats; D017207:Rats, Sprague-Dawley; D013378:Substantia Nigra / Q000187:drug effects / Q000201:enzymology / Q000473:pathology*; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
chemical_list: D018696:Neuroprotective Agents; D014446:Tyrosine 3-Monooxygenase; D008550:Melatonin; D004298:Dopamine