Progesterone Exacerbates Striatal Stroke Injury in Progesterone-Deficient Female Animals

We have previously shown that female animals experience substantial protection from brain injury after reversible middle cerebral artery occlusion (MCAO) compared with their male or ovariectomized female counterparts. The reproductive steroid estrogen has been shown to provide neuroprotection from a variety of experimental insults, but the importance of progesterone as an anti-ischemic treatment has not been well explored. We evaluated histological outcomes after MCAO in ovariectomized female rats with or without acute or chronic progesterone replacement therapy.