London, June 7 (ANI): Researchers have found a potential new target for pharmacologic control of cholesterol levels - a hormone called ghrelin in the brain that signals hunger pangs and regulates cholesterol circulation.
The animal study was led by Matthias Tschop, professor in the University of Cincinnati (UC) endocrinology division.
"We have long thought that cholesterol is exclusively regulated through dietary absorption or synthesis and secretion by the liver. Our study shows for the first time that cholesterol is also under direct 'remote control' by specific neurocircuitry in the central nervous system," said Tschop.
The hormone is important for the regulation of food intake and energy expenditure. Tschop and his team found that increased levels of ghrelin in mice caused the animals to develop increased levels of blood-circulating cholesterol. This, the authors say, is due to a reduction in the uptake of cholesterol by the liver.
Genetically deleting or chemically blocking MC4R in the central nervous system showed increased levels of cholesterol, suggesting that MC4R was the central element of the "remote control."
"We were stunned to see that by switching MC4R off in the brain, we could even make injected cholesterol remain in the blood much longer," says Tschop, a researcher at UC's Metabolic Diseases Institute.
Cholesterol - although naturally occurring fat needed by the body - can cause atherosclerosis if too much, leading to a heart attack. There are two types of cholesterol - HDL (high-density lipoprotein) and LDL (low-density lipoprotein). LDL is considered the 'bad' kind of cholesterol responsible for plaque build-up. HDL is the 'good' kind that, in high levels, can prevent atherosclerosis.
Although further tests are required to confirm the advantages of this finding, the scientists say their finding adds to a growing body of evidence for the central nervous system's direct control over essential metabolic processes.
The study appears online in Nature Neuroscience. (ANI)