Neuroprotective actions of the synthetic estrogen 17alpha-ethynylestradiol in the hippocampus.
17alpha-ethynylestradiol (EE2), a major constituent of many oral contraceptives, is similar in structure to 17beta-estradiol, which has neuroprotective properties in several animal models. This study explored the potential neuroprotective actions of EE2 against kainic and quinolinic acid toxicity in the hippocampus of adult ovariectomized Wistar rats. A decrease in the number of Nissl-stained neurons and the induction of vimentin immunoreactivity in astrocytes was observed in the hilus of the dentate gyrus of the hippocampus after the administration of either kainic acid or quinolinic acid. EE2 prevented the neuronal loss and the induction of vimentin immunoreactivity induced by kainic acid at low (1 microg/rat) and high (10-100 microg/rat) doses and exerted a protection against quinolinic acid toxicity at a low dose (1 microg/rat) only. These observations demonstrate that EE2 exerts neuroprotective actions against excitotoxic insults. This finding is relevant for the design of new neuroprotective estrogenic compounds.
Picazo
Ofir
O
Escuela Superior de Medicina del Instituto Politécnico Nacional, Plan de San Luis y Diaz Mirón Col. Sto. Tomás, 11340 Mexico DF, Mexico.
Becerril-Montes
Adriana
A
Huidobro-Perez
Delia
D
Garcia-Segura
Luis M
LM
D000818:Animals; D002452:Cell Count; D003505:Cyclodextrins / Q000494:pharmacology; D018891:Dentate Gyrus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D004997:Ethinyl Estradiol / Q000031:analogs & derivatives / Q000494:pharmacology*; D005260:Female; D006624:Hippocampus / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D007608:Kainic Acid / Q000494:pharmacology; D009474:Neurons / Q000166:cytology / Q000187:drug effects; D018696:Neuroprotective Agents / Q000494:pharmacology*; D010052:Ovariectomy; D051381:Rats; D017208:Rats, Wistar; D013194:Staining and Labeling; D014746:Vimentin / Q000378:metabolism
D003505:Cyclodextrins; D018696:Neuroprotective Agents; D014746:Vimentin; D004997:Ethinyl Estradiol; D007608:Kainic Acid