Affiliations: Brain Research Laboratory, Department of Psychology
and Department of Emergency Medicine, Emory University, Atlanta, Georgia,
30322, USA
Note: [] Corresponding author: D. G. Stein, Brain Research Laboratory,
575 Rollins Way, Atlanta, GA 30322, USA. Tel.: +1 404 727 4796; Fax: +1 404 727
2388; E-mail: dstei04@emorycdu.
Abstract: Purpose. The aim of the present study was to assess the effect of
different durations of administration of progesterone (4 mg/kg) on the
resolution of edema 6 days after medial frontal cortex contusions (MFC) in male
adult rats. Methods: Animals sustaining injury were injected with progesterone
or its vehicle for 3 days or for 5 days beginning the first hour after surgery.
On the 6th day the rats were killed and their brain water content was measured.
Results: We confirmed the presence of edema six days after MFC. However, both 3
and 5 days of treatment with progesterone significantly reduced edema in the
injured brains but the five days of treatment were more effective. The effects
of progesterone depend upon the duration of the treatment because there are two
waves of edema. The first phase begins within a few hours of the injury and the
second starts several days later. Conclusions: Our data are consistent with
earlier findings showing that longer durations of progesterone administration
lead to more complete behavioral recovery as well as to an increased number of
surviving neurons.
