According to a new study, hormones may produce different effects on the left and right-hand sides of the body and contribute to movement impairments after brain injury
Studies indicate that giving rats, without a brain injury, a particular set of hormones results in movement responses similar to human motor deficits on one side of the body.
The team investigated the effects of one-sided brain injury in rats and found that the hindlimb on the opposite side to the injury had impaired reflexes.
However, animals that lacked the pituitary gland did not experience these problems and ß-endorphin and Arg-vasopressin appeared to play a role.
“This led us to ask whether pituitary hormones might mediate in part the side-specific movement problems humans can experience after brain injury,” explains Georgy Bakalkin, Professor at the Department of Pharmaceutical Biosciences, Uppsala University, Sweden, and a co-senior author of the study.
Hormone-blocking treatment
They gave the rats without a brain injury these two hormones and found that they also developed hindlimb contraction on the right side.
Next, they administered drugs that block the effects of these hormones to the rats with left-sided brain injury and found that they did not develop right-sided movement problems, suggesting that patients who have a similar injury may be able to be treated with the same drugs.
“These observations suggest that the endocrine system through hormones in the blood may selectively target the left and right sides of the animals’ bodies. This is an unusual phenomenon that requires verification in other animal models. We must be cautious in the interpretation of these findings and their biological implications before further research is carried out. But if future studies confirm the benefits of treatments that block these hormones, they may offer a new approach to treating movement problems following stroke or injury.”
