A hormone produced in the gut appears to limit bone formation, scientists report in Cell [subscription required]. The hormone, serotonin, is the same one produced by the brain to regulate mood, learning, and sleep, but the new study finds that serotonin produced by the gut has an entirely separate function. Mice engineered to produce extra serotonin formed weak bones, while mice engineered to produce less serotonin developed extra-strong bones. The research, though still basic, suggests new avenues of osteoporosis research in humans.
“It’s what you’d call a landmark study,” Bjorn Olsen [a Harvard cell biologist who was not involved with the study] says. “It opens new doors” [Science News].
Although serotonin produced by the gut makes up 95 percent of the body's serotonin, its function had not been well understood. The connection between serotonin and bone formation revealed itself through two types of rare human diseases, both involving the geneLrp5. ...
