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TUESDAY, July 29, 2003 (HealthDayNews) -- How about a pill that would help you lose weight and lower blood cholesterol as well?
It's only a vision thus far, but pharmaceutical company researchers say they have a molecule that has been doing just that in laboratory animals.
It's a thyroid hormone kind of molecule, but one that is very different from the thyroid products now on the market, says Gary J. Grover, a senior principal scientist at the Bristol-Meyers Squibb Pharmaceutical Research Institute. Grover led the research team that reports its finding in the July 28-Aug. 1 issue of the Proceedings of the National Academy of Sciences.
Most of those drugs are for people whose thyroids do not produce enough hormone. The hormone helps reduce weight by increasing the body's metabolic rate, and they also work to keep blood cholesterol low. But thyroid hormone drugs can also have potential dangerous side effects, the most worrisome of which is a speedup of the heartbeat.
The aim of Grover's group is a drug that gives the benefits of thyroid hormone without the side effects. Their effort is based on the relatively new knowledge that there are two kinds of receptors that receive the hormone and pass its signal to the body.
With classic scientific stolidity, the two kinds of receptors are called alpha and beta. The newly reported molecule acts on the beta receptors, but leaves the alpha receptors alone.
"The thrust of our paper is that if you stimulate the beta subtype receptors you get a modest increase in the rate at which energy is burned, without an increased heart rate," Grover says. "In addition to the increase in metabolic rate, we also found that beta receptor activation causes lowering of cholesterol and lipoproteins."
High LDL cholesterol and lipoprotein blood levels are known to increase the risk of heart attack and stroke. So the work thus far, done by treating mice, rats, and monkeys with a beta stimulator called KB-141, is "a first scientific step" toward a cholesterol-lowering weight loss drug, Grover says.
He and his colleagues are now working to verify their finding. For example, they are checking to be sure that the weight reduction is due to loss of fat, rather than muscle. "Right now the consensus is that this is reasonable," Grover says. "We find that the beta activator does selectively increase fat loss."
Bristol-Meyers Squibb is not exactly betting the company on these experiments. "There are a number of things we are looking at in the obesity field, and this is one of them," says Brian Henry, a company spokesman.
And, Grover adds, "It's tough to speculate on something that is so early on."