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Parkinson’s Disease
Volume 2015 (2015), Article ID 431690, 9 pages
Research Article

Progesterone Exerts a Neuromodulatory Effect on Turning Behavior of Hemiparkinsonian Male Rats: Expression of 3α-Hydroxysteroid Oxidoreductase and Allopregnanolone as Suggestive of Receptors Involvement

1Instituto de Investigaciones Biomédicas (INBIOMED)-IMBECU-CONICET, Universidad de Mendoza, Huarpes 698, 5500 Mendoza, Argentina
2Área de Farmacología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Avenida Libertador 80, Centro Universitario, 5500 Mendoza, Argentina

Received 18 December 2014; Accepted 12 March 2015

Academic Editor: Dianbo Qu

Copyright © 2015 Roberto Yunes et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


There is a growing amount of evidence for a neuroprotective role of progesterone and its neuroactive metabolite, allopregnanolone, in animal models of neurodegenerative diseases. By using a model of hemiparkinsonism in male rats, injection of the neurotoxic 6-OHDA in left striatum, we studied progesterone’s effects on rotational behavior induced by amphetamine or apomorphine. Also, in order to find potential explanatory mechanisms, we studied expression and activity of nigrostriatal 3α-hydroxysteroid oxidoreductase, the enzyme that catalyzes progesterone to its active metabolite allopregnanolone. Coherently, we tested allopregnanolone for a possible neuromodulatory effect on rotational behavior. Also, since allopregnanolone is known as a modulator, we finally examined the action of antagonist bicuculline. We found that progesterone, in addition to an apparent neuroprotective effect, also increased ipsilateral expression and activity of 3α-hydroxysteroid oxidoreductase. It was interesting to note that ipsilateral administration of allopregnanolone reversed a clear sign of motor neurodegeneration, that is, contralateral rotational behavior. A possible involvement modulated by allopregnanolone was shown by the blocking effect of bicuculline. Our results suggest that early administration of progesterone possibly activates genomic mechanisms that promote neuroprotection subchronically. This, in turn, could be partially mediated by fast, nongenomic, actions of allopregnanolone acting as an acute modulator of GABAergic transmission.