June 18, 2013
Study Says Two Drug Types May Combat Obesity And Treat Metabolic Syndrome
redOrbit Staff & Wire Reports - Your Universe Online
Medications typically prescribed to treat heart failure and high blood pressure could potentially be used to battle obesity and the combination of disorders known as metabolic syndrome, according to research presented over the weekend at the Endocrine Society's 95th Annual Meeting (ENDO 2013) in San Francisco.Weight gain — especially around the waist — and hypertension are two of the health abnormalities that comprise metabolic syndrome, a condition which can increase a person´s risk of developing heart disease, diabetes and other serious adverse medical conditions.
Researchers have been experimenting with different types of drugs in an attempt to prevent metabolic syndrome as well as to battle soaring obesity rates. The research presented Saturday at the ENDO 2013 conference focused on substances that can block the function of the hormones known as aldosterone and glucocorticoids.
These hormones are synthesized in the adrenal cortex of mammals and help activate mineralocorticoid receptors (MRs), ligand-activated transcription factors which are essential to a variety of physiological and pathological processes in several parts of the body, including the kidneys, heart and adipose (fat) tissue.
Drugs which prevent MRs from reacting to their ligands are known as MR antagonists, and the researchers behind this latest study examined the effects of two such MR antagonists, drospirenone and spironolactone, in mice that ate a diet high in fatty foods. Drospirenone and spironolactone are both currently used in clinical practice, and both have previously been demonstrated to modulate adipocyte differentiation in vitro, the researchers explained.
In animal studies, Massimiliano Caprio of the IRCCS San Raffaele Pisana Research Center in Rome, Italy and colleagues discovered that the MR antagonists had several benefits, including the prevention of weight gain and an increase in the number of energy-burning fat cells.
Furthermore, the test animals that received the drugs in combination with a high-fat diet exhibited an increased number of so-called “good” brown fat cells interspersed with white adipose tissue in comparison to untreated control subjects. Brown fat cells burn energy to help prevent weight gain while white fat cells store energy as more fat cells.
They also used special imaging test to measure the percentage of water in fat cells in order to evaluate the expansion of brown adipose tissue. High levels of water in adipose tissue indicate the presence of brown fat, they explained. Additionally, the researchers discovered MR antagonists helped reduce blood glucose levels related to the pre-diabetic state of hyperglycemia known as impaired glucose tolerance.
“These data open new unexpected applications of MR antagonists in the treatment of obesity and its metabolic complications, since their use in animal models reverses the metabolic dysfunction induced by a high-fat diet, promoting the activation of brown-like fat in classical white fat depots,” explained lead author Andrea Armani, a post-doctoral fellow in obesity research. “Indeed, MR antagonism has promise as a novel approach to treat metabolic syndrome.”