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Published in final edited form as:
Brain Res. 2009 February 27; 1257: 94–101. doi:10.1016/j.brainres.2008.12.048.
Effects of progesterone administration on infarct volume and
functional deficits following permanent focal cerebral ischemia in
rats
Tauheed Ishrat, Ph.D., Iqbal Sayeed, Ph.D., Fahim Atif, Ph.D., and Donald G. Stein, Ph.D.*
Department of Emergency Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
Abstract
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Recent experimental evidence indicates that progesterone (PROG) protects against various models
of brain injury, including ischemic stroke. Most human studies of pharmacologic treatments for acute
cerebral stroke have failed despite initial success in animal models. To simulate better the typical
human stroke without reperfusion, the present study was conducted to examine the efficacy of PROG
on infarct volume and functional outcome in a permanent model of stroke, using direct cauterization
of the middle cerebral artery (MCA). Twenty-four male adult Sprague-Dawley rats underwent
pMCAO by electro-coagulation and sham operation. After induction of permanent MCA occlusion
(pMCAO), the rats received an initial intraperitoneal injection of PROG (8 mg/kg) or vehicle at 1h
post-occlusion followed by subcutaneous injections at 6, 24 and 48 h. Functional deficits were tested
on the rotarod and grip strength meter at 24, 48 and 72 h after pMCAO. The rats were killed 72 h
after surgery and isolated brain was sectioned into coronal slices and stained with 2, 3, 5triphenyltetrazolium chloride (TTC). PROG-treated rats showed a substantial reduction (54.05%) in
the volume of the infarct (% contralateral hemisphere) compared to vehicle controls. In addition there
was a significant improvement in ability to remain on an accelerating rotarod and increased grip
strength observed in the pMCAO rats treated with PROG compared to vehicle. Taken together, these
data indicate that PROG is beneficial in one of the best-characterized models of stroke, and may
warrant further testing in future clinical trials for human stroke.
Keywords
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Progesterone; Brain damage; Permanent MCAO; Functional recovery; Infarct volume
1. Introduction
Stroke, an obstruction of blood flow in a major cerebral vessel, can cause permanent
neurological damage, an area of infarcted tissue, severe functional impairments and death if
not managed quickly (Hankey, 1999; Muntner et al., 2002). It is the second most frequent cause
of death world-wide and the third leading cause of adult disability in the United States (Feigin,
2005). Currently, treatment options for stroke are limited, and many promising drugs have
failed in human clinical trials due to intolerable side effects or therapeutic limitations. These
* Address for reprints and correspondence: Department of Emergency Medicine, Brain Research Laboratory, 1365B Clifton Road NE,
Emory University, Atlanta, GA 30322, USA, Phone: (404) 712-2540, Fax: (404) 727-2388, donald.stein@emory.edu.
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Ishrat et al.
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failures are to some extent attributable to approaches that did not conform to Stroke Therapy
Academic Industry Roundtable (STAIR) guidelines, notably the lack of appropriate preclinical models. A safe and effective therapeutic strategy which can block or reduce the many
harmful effects of ischemia–including excitotoxicity, oxidative stress, inflammation apoptosis,
necrosis and acidosis (Danton and Dietrich, 2003; Mergenthaler et al., 2004)—is urgently
needed.
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A large body of evidence now suggests that the steroid hormone progesterone (PROG) has
pharmacotherapeutic effects in several experimental injury models of stroke and trauma
(reviewed by Stein and Hurn, in press). The neuroprotective efficacy of PROG in functional
and morphological recovery has been confirmed both permanent and transient stroke models
by our recent studies (Sayeed et al., 2006; 2007) and previous studies of others (Betz and
Coester, 1990; Jiang et al., 1996; Chen et al., 1999; Murphy et al., 2002; Gibson and Murphy,
2004; Gibson et al., 2005). In addition to animal studies, two recent randomized, double-blind,
placebo-controlled clinical trials using 3 or 5 days of intravenous PROG to treat patients with
moderate to severe traumatic brain injury (TBI) demonstrated both safety and efficacy
compared to patients given standard of care treatment plus placebo (Wright et al., 2007; Xiao
et al., 2008). In the Wright, et al. trial, the severely injured patients given PROG had almost a
60% reduction in mortality and those diagnosed with ‘moderate’ brain injury had a significantly
better functional outcome at 30 days after injury. Xiao and colleagues essentially confirmed
these findings while also reporting functional improvements extending out to 6 months postinjury. Whether PROG would be beneficial in the clinical treatment of stroke has not yet been
investigated in clinical trial.
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Permanent or thromboembolic occlusion of cerebral arteries, especially middle cerebral artery
occlusion (MCAO), is the commonest type of focal stroke in humans (Delcker et al., 1993;
Hacke et al., 1996). For this reason, although its recommendations are still controversial,
STAIR endorses the testing of agents in permanent models of ischemia to simulate better the
typical human stroke without reperfusion (Fisher, 2003). More recently Stem cell Therapeutics
as an Emerging Paradigm in Stroke (STEPS) recommended that it is imperative for
translational research that the therapeutic agent be tested in clinically relevant multiple models
of stroke, in two species, in both genders and in multiple laboratories (Borlongan et al.,
2008). Permanent MCAO (pMCAO) with intraluminal thread technique is a widely used
animal model of stroke. However, it has an important drawback: insertion of the thread leads
to obstruction of the hypothalamic artery and thus to hyperthermia, which in turn increases
infarct volume, worsens functional outcome (Zhao et al., 1994; Reglodi et al., 2000), and
confounds drug evaluation (Memezawa et al., 1995). In addition, this model shows variability
in infarct volumes and higher mortality rates (Kitagawa et al., 1998). In contrast, direct
‘ligation’ (cauterization) of the MCA in rats as developed by Tamura et al. (1981) has become
the most reproducible and suitable model for approximating the pathology and symptoms of
human stroke (Yamamoto et al., 1988; Hunter et al., 1998).
Most studies of PROG as a neuroprotective agent in stroke have been done with intraluminal
MCAO models. The first study, published almost twenty years ago, examined PROG as a
neuroprotective agent against brain edema in permanent focal stroke in rat by direct ligation
of the MCA (Betz and Coester 1990). In the present study, we evaluated the effect of PROG
on infarct attenuation and functional outcomes following direct permanent ligation of the
MCA. Our results support the efficacy of post-administration of PROG in reducing infarct
volume and improving functional outcome following cerebral ischemia.
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2. Results
2.1 Physiological variables
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Physiological variables (SpO2, heartbeat, body temperature) were measured at 10 min before
and 90 min after cerebral ischemia. There were no significant differences (P<0.05) in
physiological parameters among the sham-operated, pMCAO and pMCAO + PROG-treated
groups (Table 1).
2.2 Effect of PROG on infarct volume after pMCAO
Figure 1 illustrates the effects of PROG on infarct volume (expressed as percent of intact
contralateral structure). Figure 1A shows representative brain slices stained with TTC 72 h
after pMCAO in vehicle-treated and PROG-treated rats. Figure 1B shows the distribution of
percent area of infarct in serial brain sections stained with TTC 72 h after pMCAO in vehicletreated and PROG-treated rats. PROG administration significantly (P< 0.05) reduced the total
infarct volumes after pMCAO in the PROG-treated compared with vehicle-treated rats (20.11
± 3.1 vs. 9.24 ± 2.96, respectively).
2.3 Effect of PROG on functional outcome after pMCAO
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2.3.1 Rotarod test—Time spent on the rotarod is expressed as a percentage of pre-surgery
control value. A repeated measures ANOVA on latency to remain on the rotarod showed
significant group (F (2,63) =17.34, p<0.05) and time (F(3,63) = 42.22, p<0.05) effects. The
rotarod tests showed significant (P < 0.05) deficits in motor performance (time spent on the
rotarod) in pMCAO-plus-vehicle-treated rats (45.77 ± 12.42, 59.09 ± 14.24, 64.26 ± 12.70 at
24, 48, and 72 h post-occlusion, respectively) at all time points compared to shams (86.10 ±
18.34, 91.12 ± 8.66, 97.33 ± 13.90 at 24, 48, and 72 h post-occlusion, respectively. Repeated
treatments with PROG after pMCAO significantly (P<0.05) improved the ability to remain on
the rotarod (68.46 ± 15.11, 77.34 ± 17.11, 86.62 ± 18.46 at 24, 48, and 72 h post-occlusion,
respectively) at all time points (Fig. 2).
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2.3.2 Grip-strength test—Treatments with PROG improved grip-strength score (in
Newtons) resulting from pMCAO (Fig 3). There was no difference in the grip-strength score
before surgery in any of the groups (10.11 ± 0.46 N, 9.9 ± 0.24 N, 10.12 ± 0.29 N in sham,
pMCAO + vehicle, pMCAO + PROG, respectively). A repeated measures ANOVA on grip
strength showed significant group (F (2,63) = 44.07, p<0.05) and time (F(3,63) = 22.38, p<0.05)
effects. Grip-strength was decreased significantly (P < 0.05) in rats subjected to pMCAO (6.17
± 0.81 N, 6.80 ± 0.78 N, 7.48 ± 0.92 N at 24, 48, and 72 h post-occlusion, respectively) at all
time points as compared to shams (9.04 ± 0.35 N, 9.12± 0.78 N, 9.70 ± 0.41 N at 24, 48, and
72 h post-surgery, respectively), but was significantly (P < 0.05) improved with the repeated
treatment with PROG (7.77 ± 0.76 N, 8.16 ± 1.0 N, 9.11 ± 0.54 N at 24, 48, and 72 h postsurgery, respectively).
3. Discussion
We show that a short course of post-injury treatment with PROG reduces cortical infarct
volume and leads to an attenuation of the deficits in accelerating rotarod and grip strength
testing after 72 h of pMCAO in rats. This neuroprotection with PROG in a cerebral ischemic
injury model is consistent with our previous reports (Sayeed et al., 2006; 2007) and those of
others (Betz and Coester, 1990; Jiang et al., 1996; Chen et al., 1999; Murphy et al., 2002;
Gibson and Murphy, 2004; Gibson et al., 2005). A recent study by Aggarwal et al. (2008) also
demonstrated neuroprotective efficacy of PROG following partial global ischemia in mice.
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In the present study the 8 mg/kg doses selected were based on previous findings showing the
maximal effectiveness of PROG in the treatment of brain injury (Jiang, et al., 1996; Chen, et
al., 1999; Kumon, et al., 2000; Goss, et al., 2003; Djebaili, et al., 2004). PROG administered
at a dose of 8 mg/kg, has been shown to be effective in reducing infarct volume and functional
deficits in mice following MCAO (Gibson and Murphy, 2004). In rats, a dose of 8 mg/kg
reduces lesion volume (Chen, et al. 1999; Kumon, et al., 2000), while lower (4 mg/kg) or higher
doses (32 mg/kg) failed to have the same effect (Chen, et al., 1999) following cerebral ischemia.
In our studies, it was considered more relevant to administer PROG after, rather than before,
the behavior testing because of PROG's known sedative, anxiolytic, and anesthetic activity
(Merryman, et al., 1959; Bixo and Backstrom 1990; Bitran, et al., 1995; Reddy, and Kulkarni,
1997; Djebaili, et al., 2004).
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In virtually all cases, stroke is likely to induce death and/or dysfunction of brain cells, which
then cause neurological impairments that depend on the volume and location of the ischemic
brain area. Although important from an experimental perspective, lesion volume analysis by
itself gives little indication of how profoundly affected an individual will be after stroke (Wahl
et al., 1992; Hattori et al., 2000; Reglodi et al., 2003). In our study, treatment with PROG
significantly reduced the infarct volume following pMCAO in rats. Overall, we found that the
average total volume of infarction was reduced by 54.05% compared to the vehicle-treated
group. These data corroborate our previous finding that PROG attenuates infarct volume in a
transient and permanent suture rat model of stroke (Sayeed et al., 2006). Other studies have
demonstrated PROG to be neuroprotective following global ischemia in cats (Gonzalez-Vidal
et al., 1998; Cervantes et al., 2002) and focal ischemia in rats (Jiang et al., 1996; Chen et al.,
1999; Murphy et al., 2002; Gibson and Murphy, 2004; Gibson et al., 2005). However, in one
report Schiff and colleagues failed to observe any benefit of PROG treatment after brain injury
in rats (Gilmer et al., 2008).
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Muscle weakness or motor impairment is a common complaint after stroke in humans. So it
is important for the pathophysiological study and development of drug therapies for stroke to
use appropriate behavioral testing in conjunction with histological measurement (Bederson et
al., 1986; Corbett and Nurse, 1998). In this study, we used accelerating rotarod and grip strength
to evaluate the effect of PROG on behavioral outcome. Previous studies have shown that PROG
improved deficits on the Zea Longa's neurological outcome measurement scale (Jiang et al.,
1996; Chen et al., 1999; Kumon et al., 2000), rotarod performance and somatosensory neglect
following transient (Chen et al., 1999) and permanent (Gibson and Murphy, 2004; Sayeed et
al., 2007) MCAO. Consistent with the earlier observations, we found that behavioral deficits
caused by pMCAO were significantly improved by PROG treatment at 24, 48, and 72 h after
the surgery. The degree of improvement was substantial (approximately return to normal
functioning) at 72 h post-occlusion.
The mechanism(s) of action by which PROG provides neuroprotection against infarction
volume and functional benefits to rats that have undergone direct surgical MCAO are not
completely known. PROG readily crosses the BBB and therefore reperfusion is not required
to achieve adequate penetration to observe efficacy in a permanent model of ischemia. This is
particularly relevant clinically since the majority of human stroke victims suffer from
permanent occlusion (Hacke et al., 1996; Kassem-Moussa and Graffagnino 2002). Increasing
evidence suggests that multiple deleterious pathological events may contribute to ischemic
injury, such as excitotoxicity, oxidative stress, inflammation apoptosis, and necrosis (Danton
and Dietrich, 2003; Mergenthaler et al., 2004). Because it is a pleiotropic agent it is likely that
PROG acts by a combination of intranuclear and membrane mechanisms. PROG exerts its
action primarily through the intracellular membrane-bound PROG receptor by inhibiting
NMDAr-Ca2+ influx and activation of PR-mediated Src-ERK signaling pathways (Luconi et
al., 1998; Cai et al., 2008). A number of studies have shown the multiple pathways by which
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PROG may exert its action in experimental brain injury, including its potentiating effect on
GABA inhibition and attenuation of excitatory amino acid responsiveness, amplification of
adenosine's inhibitory action on cerebral cortical neuronal activity, anti-apoptotic and
antioxidant action, reduction of brain edema, and action as a free radical scavenger (Majewska,
1992; Roof, et al., 1997; He et al., 2004; Smith and Woolley, 2004; Djebaili et al., 2005; Gibson
et al., 2005; Mani, 2006).
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Brain edema accounts for much of the morbidity and mortality following stroke. PROG has
consistently been shown to reduce edema both following TBI (Roof e al., 1993; Wright et al.,
2001; Guo, et al., 2006) and permanent ischemia (Betz and Coester 1990 a and b). Our recent
results suggest that PROG modulates expression of AQP4 (Guo et al., 2006), a water channel
protein shown to be critically involved in the formation and resolution of brain edema following
ischemic brain injury (Frydenlund et al., 2006). Other mechanisms for the hormone's
pleiotropic actions in enhancing neuronal sparing and repair after various kinds of brain injury
have been reviewed elsewhere (Stein, 2008; Stein and Hurn, 2008). Recently, Cutler et al.
(2007), found that in a rat model of TBI, acute PROG treatment helped to reduce inflammatory
factors such as COX-2, IL-6 and NFkappaB at various time points after the injury. Since the
stroke model also induces edema, it is likely that post-stroke administration of PROG would
have similar benefits. Furthermore our laboratory has also shown (Vanlandingham, et al.,
2007) that after a brain injury treatment with PROG increases the expression of CD-55, a cell
surface protein which has the capacity to reduce complement factor convertases that trigger
the inflammatory cascade capable of causing secondary neuronal loss. Since the enantiomer
of PROG can also reduce edema (Vanlandingham et al., 2006), it is likely that some of the
mechanisms of action do not require the activation of the intranuclear PROG receptor, but
further work is needed to determine exactly how the reparative process unfolds.
In conclusion, PROG treatment significantly reduced infarct volume and improved functional
deficits in a clinically relevant model of stroke and continues to show pre-clinical promise as
a potential therapeutic strategy for stroke patients. Further investigations are needed to evaluate
time-response mechanisms of action of PROG in an experimental, permanent stroke model.
4. Experimental procedures
4.1. Animals and treatment regimen
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Twenty-four adult male Sprague-Dawley rats (300 to 340 g; Charles River Laboratories,
Wilmington, MA, USA) were used according to procedures approved by the Institutional
Animal Care and Use Committee, Emory University, Atlanta, GA, USA (protocol 151-2005).
The rats were quarantined for at least 7 days before the experiment. The animals were housed
in individual cages in a room maintained at 21–25°C, 45–50 % humidity and 12-h light/dark
cycle with free access to pellet chow and water.
The animals were separated into three groups of eight rats each. Group I: sham-operated
vehicle-treated control (S); group II: pMCAO and vehicle-treated stroke (pMCAO); group III:
pMCAO and PROG (8 mg/kg) (pMCAO + PROG). Consistent with previous research, PROG
(P-0130; Sigma-Aldrich Co., St. Louis, MO, USA) was dissolved in 22.5% 2-hydroxypropylb-cyclodextrin and given in a dose of 8 mg/kg by intraperitoneal injection 1 h post-occlusion
to ensure more rapid absorption following injury. Additional injections of 8 mg/kg were
administered subcutaneously 6, 24, and 48 h post-MCAO. PROG was administered after
performing the behavior testing. The PROG dose used in this experiment was determined from
previous studies showing that this amount provided the maximal protective effects in the
treatment of different types of brain injury (Jiang et al., 1996; Chen et al., 1999; Kumon et al.,
2000; Goss, et al., 2003; Djebaili, et al., 2005; Sayeed et al., 2006; 2007).
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4.2. Induction of permanent focal cerebral ischemia
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For pMCAO in rats, isoflurane anesthesia was induced by 5% and maintained with 1.5-2%
during surgery, in 2:1 nitrous oxide and oxygen. The original technique as described by Tamura
et al. (1981) and Yamamoto et al. (1988) was used, with minor modifications, in our
experiments to produce consistency in the ischemic injury. In brief, a ventral midline incision
was made for exposure of both common carotid arteries (CCA). The contralateral right CCA
was permanently ligated using a 3/0 silk suture. The ipsilateral (left) CCA was temporarily
occluded for 90 min using a Mayfield micro-aneurysm clip just after the permanent occlusion
of the MCA. A vertical incision was made midway between the left orbit and the left external
auditory canal. After anterior and downward retraction of the musculature, the zygomatic bone
was left intact, and the pterygoid muscles and mandibular nerve were retracted to expose the
ventral surface of the skull. Under an operating microscope, the bone around the foramen ovale
was burnished (2-3 mm) away to expose the MCA, and the craniectomy was extended dorsally
up to the first major branch of the MCA. The dura was opened with a bent 26-gauge needle,
the arachnoid membrane was gently removed and the MCA cauterized and cut permanently to
prevent recanalization with a bipolar electrocauterizer without damaging the brain surface. The
site of the occlusion is midway between the inferior cerebral vein and olfactory tract. The rats
were allowed to recover from anesthesia on the heating pad and then returned to their home
cages after full recovery from anesthesia. Sham-operated rats were subjected only to exposure
of the MCA without coagulation. Anesthesia duration was similar in all groups.
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Temperature was monitored and maintained (37±2°C) during surgery by a homeothermic
heating blanket system (Harvard Apparatus, Holliston, MA, USA). Pulse oximetry (model
V3304; Waukesha, WI, USA) was used to maintain heart rate at approximately 350 beats per
minute with blood oxygen saturation (SpO2) levels > 95 %.
4.3. Analysis of infarct volume
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The rats were killed 72 h post-occlusion with an overdose (75 mg/kg) of Nembutal sodium
solution. The brains were carefully removed and placed in chilled saline, and then sliced into
5 serial coronal sections of 2 mm thickness using a rat brain matrix (Harvard Apparatus) starting
at 3 mm posterior to the anterior pole. After sectioning, the slices were stained with 2% 2, 3,
5-triphenyltetrazolium chloride (TTC; Sigma Chemical Co.) in saline and kept for 15 min at
37°C in the dark. Stained sections were then fixed in 10% buffered formalin. Both hemispheres
of each stained coronal section were scanned using a high-resolution scanner (Epson Perfection
2400 Photo), and then evaluated by digital image analysis (Image Pro System, Media
Cybernetics, Silver Spring, MD, USA). The unstained area representing the infarct was
integrated across sections and affected hemisphere was expressed as a percentage of the
corresponding intact, contralateral structure. These techniques have been used repeatedly in
the literature to measure and evaluate stroke outcome in experimental preparations (Bederson
et al., 1986; Belayev et al., 1999).
4.4. Assessment of functional deficits
The experiment was performed between 9:00 a.m. and 4:00 p.m. The investigator applying the
functional tests did not know the identity of the experimental treatment groups until completion
of the data analysis.
4.4.1. Rotarod—Motor impairment was assessed using an accelerating rotarod (Columbus
Instruments Rotamex 4/8 system, OH, USA, Model 7750). Rotameric tests were performed
according to our previous studies (Sayeed et al., 2007). All rats were given 3 training sessions,
10 minutes apart, before surgery to establish baseline performance. Rats were first habituated
to the stationary rod, and then exposed to the rotating rod. The rod was started at 4 rpm and
accelerated linearly to 30 rpm within 300 sec. Latency to fall off the rotarod was then
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determined before ischemia (presurgery) and at 24, 48 and 72 h post-surgery in all rats. The
rats were required to stay on the accelerating rod for a minimum of 30 sec. If they were unable
to reach this criterion, the trial was repeated for a maximum of five times. The two best (largest)
fall latency values a rat could achieve were then averaged and used for data analysis. Rats not
falling off within 5 min were given a maximum score of 300 seconds
4.4.2. Grip strength—Forelimb grip strength in rats was determined before ischemia and
24, 48 and 72 h after surgery using a grip strength meter (Columbus Instruments, OH, USA).
We used an electronic digital force gauge that measured the peak force exerted by the action
of the animal while grouping the sensor bar. While being drawn back along a straight line
leading away from the sensor, the animal released its grip at some point and the gauge then
recorded the maximum force attained at the time of release. The digital reading (in Newtons)
of three successive trials were obtained for each rat, averaged and used for data analysis. The
pMCAO, vehicle- and PROG-treated rats were tested simultaneously with the shams.
4.5. Data analysis
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All results were expressed as mean ± SD and calculations were obtained using GraphPad Prism
and SPSS 11.0 software. Lesion volumes were analyzed using the Student's t-test. Rotarod
performance and Grip strength were analyzed by one way analysis of variance (ANOVA), for
repeated measures followed by Tukey's test for individual comparisons. Percent difference
between pre and post-surgical scores for each animal was used to control for individual
differences in Rotorod performance. The criterion for statistical significance was set at P<0.05.
Acknowledgements
This work was supported by NIH grants R01 NS04851 and Rooms to Go Scholar award. We acknowledge Leslie
McCann for her help in manuscript preparation.
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Figure 1. PROG reduces infarct volume in a rat model of pMCAO
A) TTC-stained coronal sections from representative rats given either vehicle or PROG, brains
harvested at 72h post occlusion. Infarcts are shown as pale (unstained) regions. The infarct
area in PROG-treated rats is substantially reduced. B) Line graph shows the percent area
distribution of infarction to the area of the contralateral side in each of five forebrain sections
in pMCAO and pMCAO plus PROG treated groups. Values are mean ± SD.
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Figure 2. PROG reduces motor impairment following pMCAO
Motor ability as assessed using the rotarod. The rotometric performance significantly (P < 0.05)
decreased in rats subjected to pMCAO plus vehicle treated compared to sham-operated plus
vehicle. PROG-treated rats were less impaired than vehicle-treated rats at all time points (24,
48, 72 h post-injury). They were able to remain on the rotarod for a significantly (P < 0.05)
greater amount of time (P < 0.05 compared with pre-surgery values). Time spent on the rotarod
is expressed as a percentage of pre-surgery control value as percentage mean ± SD. [(P <
0.05) a = significant difference compared to Sham + Vehicle vs. pMCAO + Vehicle; (P <
0.05) b = significant difference compared to pMCAO + Vehicle vs. pMCAO + PROG].
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Figure 3. PROG improves grip strength in rat model of pMCAO
Values are expressed as mean ± SD. The rats subjected to pMCAO + vehicle showed
significantly (P < 0.05) lower grip strength scores at all time points as compared to sham +
vehicle rats. PROG-treated rats showed significantly (P < 0.05) improved average scores at all
time points (24, 48, 72 h post-injury) compared to pMCAO plus vehicle-treated animals. [(P
< 0.05) a = significant difference compared to Sham + Vehicle vs. pMCAO + Vehicle; (P <
0.05) b = significant difference compared to pMCAO + Vehicle vs. pMCAO + PROG].
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Table 1
Physiological Monitor
Group
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SpO2
Heart beats
Temperature
95.21 ± 2.87
354.42 ± 6.52
36.95 ± 1.34
95.20 ± 2.86
352.78 ± 6.54
37.00 ± 2.28
96.0 ± 3.75
350.45 ± 5.42
37.03 ± 2.21
94.54 ± 2.95
354.74 ± 4.89
36.59 ± 1.31
95.45 ± 2.46
356.16 ± 8.38
36.78 ± 2.40
95.12 ±1.98
355.25 ± 5.02
36.89 ± 1.44
Sham
pMCAO
pMCAO + PROG
10 minutes before occlusion; 90 minutes after occlusion
Values are expressed as mean ± SD. The physiological parameters (blood SpO2, heart beats and temperature) were monitored at 10 minutes before and
90 minutes after occlusion. There were no significant differences among the groups for these parameters.
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