The researchers, from the School of Medicine at The Johns Hopkins University (Baltimore, Maryland), have their results published in the February 27, 2007 issue of Proceedings of the National Academy of Sciences.
Within the experiment, the researchers injected the drugs into mice. Results showed that AMP kinase, an enzyme widely used to increase appetite, was raised to four times normal levels. The researchers, then, gave leptin, a hormone that suppresses appetite, to the mice. Consequently, levels of AMP kinase dropped back to normal levels.
The researchers found that these three drugs neutralize the protein histamine, similarly to how antihistamine drugs treat allergies. Thus, both atypical antipsychotics and antihistamines increase the chance of weight gain in humans. Both types of drugs block histamine activity and consequently increase AMP kinase.
The researchers hope that their discovery will help scientists eventually control weight more safely, along with help physicians better medicate their patients suffering with psychoses such as schizophrenia.