Estradiol reduces seizure-induced hippocampal injury in ovariectomized female but not in male rats.
Estrogens protect ovariectomized rats from hippocampal injury induced by kainic acid-induced status epilepticus (SE). We compared the effects of 17beta-estradiol in adult male and ovariectomized female rats subjected to lithium-pilocarpine-induced SE. Rats received subcutaneous injections of 17beta-estradiol (2 microg/rat) or oil once daily for four consecutive days. SE was induced 20 h following the second injection and terminated 3 h later. The extent of silver-stained CA3 and CA1 hippocampal neurons was evaluated 2 days after SE. 17beta-Estradiol did not alter the onset of first clonus in ovariectomized rats but accelerated it in males. 17beta-Estradiol reduced the argyrophilic neurons in the CA1 and CA3-C sectors of ovariectomized rats. In males, estradiol increased the total damage score. These findings suggest that the effects of estradiol on seizure threshold and damage may be altered by sex-related differences in the hormonal environment.
Galanopoulou
Aristea S
AS
Department of Neurology, Albert Einstein College of Medicine, Bronx, NY, USA. aris3@aol.com
Alm
Elizabeth Medina
EM
Velísková
Jana
J
D000818:Animals; D004827:Epilepsy / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D004958:Estradiol / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D006624:Hippocampus / Q000187:drug effects* / Q000293:injuries / Q000473:pathology; D008094:Lithium / Q000633:toxicity; D008297:Male; D018721:Muscarinic Agonists / Q000633:toxicity; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D018696:Neuroprotective Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D010052:Ovariectomy / Q000379:methods; D010862:Pilocarpine / Q000633:toxicity; D051381:Rats; D012727:Sex Characteristics
D018721:Muscarinic Agonists; D018696:Neuroprotective Agents; D010862:Pilocarpine; D004958:Estradiol; D008094:Lithium