To investigate the chronic effects of a novel
thyrotropin-releasing hormone analog,
JTP-2942 (N(alpha)-[(1S, 2R)-2-methyl-4-oxocyclopentylcarbonyl]-L-histidyl-L-
prolinamide monohydrate), on behavioral changes after
stroke, the authors examined its effects on motor and
neurologic deficits using a middle cerebral artery (MCA) occlusion model in rats. A left MCA was permanently occluded at a proximal site. From 1 week after occlusion,
JTP-2942 was intravenously administered once a day for 4 weeks. Sensorimotor performance was evaluated weekly for 10 weeks after the occlusion. The ability of the rat to maintain its body position on an inclined plane and neurologic examination based on
hemiparesis and abnormal posture were examined. After all behavioral examinations were completed, the degree of shrinkage of the left hemisphere was measured. The ability of MCA-occluded rats to maintain body position on an inclined plane in the left-headed position was significantly lower than that of
sham-operated rats throughout the test period.
JTP-2942 gradually improved this deficit dose dependently, and a dose of 0.03 mg/kg of
JTP-2942 significantly improved performance to the levels of the
sham-operated rats.
Neurologic deficits were also observed in MCA-occluded rats.
JTP-2942 also significantly improved these deficits dose dependently. On the other hand,
CDP-choline (500 mg/kg, administered intravenously), a therapeutic agent for the disturbance of consciousness and
hemiparesis after
stroke, improved
neurologic deficits but did not affect the motor deficits measured using the inclined plane. It is noteworthy that the effects of
JTP-2942 on these deficits were observed 4 weeks after cessation of drug administration. Furthermore, there was no difference in the degree of shrinkage of the cerebrum among the MCA-occluded groups. In the present study, long-lasting improving effects of
JTP-2942 on the impairment of motor and neurologic functions were observed in rats with MCA occlusion, which continued after cessation of drug administration and which were not attributable to a reduction in ipsilateral cerebral shrinkage. It is considered that the effect of
JTP-2942 on functional recovery is attributable to the activation of substitutive functions such as neuronal reconstruction. These pharmacologic properties of
JTP-2942 may be of interest for the treatment of patients with motor and
neurologic deficits during the chronic or subacute phase of
stroke.