The hormone vasopressin long known to be key to maintaining the body's water balance can also prevent brain cells from swelling, according to a new study. The findings may bring new ways to treat cerebral edema, which is the swelling that can happen after traumatic brain injuries, the researchers say.

The study showed the hormone is released into the brain when bodily fluids become more diluted than usual, said study researcher Dr. Yasunobu Okada, director-general of the National Institute for Physiological Sciences in Japan.

If vasopressin wasn't released into the brain , the diluted body fluids would cause brain cells to take up water, and the swelling could persist until the brain cells die, Okada said.

The finding means that vasopressin can be applied to future "approaches for treatment of brain edema or swelling, which is caused by swelling of brain neurons" during traumatic injury, Okada told MyHealthNewsDaily.

Researchers have long known that when the salts and sugars in the blood become more concentrated than usual, such as during dehydration, vasopressin is released and suppresses production of urine by the kidneys, conserving as much water as possible within the body.

The new study reveals that vasopressin acts not only on the kidneys, but also in the brain . Researchers found this by tagging vasopressin neurons in mice with a green fluorescent protein.

Vasopressin can work in both the brain and the kidneys because receptor proteins for the hormone exist in both organs, Okada said. Now, more research is needed to determine which brain neurons possess these receptor proteins, he said.

Pass it on: Antidiuretic hormone vasopressin can also act in the brain to prevent swelling.

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