WASHINGTON (AP) -- Scientists may have found a hormone that helps fight diabetic insulin resistance in one of the least likely places -- fat cells.
The hormone -- called adiponectin or Acrp30 -- helped diabetic mice overcome insulin resistance in tests conducted by researchers in New York and Japan.
Two independent groups both report their findings in papers in the August issue of the journal Nature Medicine.
Researchers led by Philipp E. Scherer at Albert Einstein College of Medicine in New York found the protein reduced insulin resistance over several hours after being given to diabetic mice.
And Takashi Kadowaki's team at the University of Tokyo got similar results in longer-term studies lasting several weeks.
While both researchers recorded reductions in blood sugar levels after administering adiponectin, they differed in their assessment of how the hormone works. Both stressed that their findings are preliminary and said they have no immediate plans for human testing.
Nonetheless, the findings could point the way to further research in combatting insulin resistance.
The papers show that, contrary to long-term belief, fat is more than just a storehouse for energy to be used later by the body. It also produces needed chemicals such as adiponectin.
''The main take-home messages from both papers is that fat tissue can release factors that influence insulin sensitivity in other tissues. Activation of this protein or its receptor may offer a way to improve insulin sensitivity in insulin resistant patients and may offer a complementary therapeutic approach to existing treatments,'' Scherer said.
Mice with little or no body fat lack adiponectin, they found, and it is reduced in obese mice, making them less able to use insulin.
''Levels are usually inversely correlated with fat mass -- i.e. the more fat, the less adiponectin, which is surprising for a protein that exclusively originates in fat,'' Scherer explained.
Obesity has long been associated with diabetes.