Should you have missed it, the following is an excerpt from “Bone Finding May Point To Hope for Osteoporosis” in The New York Times*:
“Bone formation appears to be controlled by serotonin, a chemical previously known mainly for its entirely separate role in the brain, researchers are reporting. The discovery could have enormous implications, osteoporosis experts say, because there is an urgent need for osteoporosis treatments that actually build bone...
At its heart is serotonin made by the gut rather than the brain, whose role outside the brain had been a mystery. Ninety-five percent of the body’s serotonin is made by the gut, but gut serotonin cannot enter the brain because it is barred by a membrane, the so-called blood-brain barrier.
Dr. Gerard Karsenty, chairman of the department of genetics and development at the Columbia University College of Physicians and Surgeons discovered that LRP5 acts on the gut’s serotonin-producing cells. The gut blocks an enzyme that converts the amino acid tryptophan to serotonin. The more LRP5, the more the enzyme is blocked, and the less serotonin is made. The gene has no effect, apparently, on brain cells that make serotonin.
Karsenty reports, though, that gut serotonin can directly control bone formation. It is released in the blood, and the more serotonin that reaches bone, the more bone is lost. Conversely, the less serotonin, the denser and stronger bones become. Dr. Karsenty was even able to prevent menopause-induced osteoporosis in mice by slowing serotonin production. Osteoporosis researchers were dumbfounded by the report…
Bone is constantly being formed and absorbed, but when the balance shifts toward loss more than formation, the result can be osteoporosis. Dr. Karsenty’s hope is to find a drug that depresses the gut’s serotonin synthesis and stimulates bone growth in these patients.”
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*The New York Times, “Bone Finding May Point To Hope for Osteoporosis” by Gina Kolata, November 26, 2008.
