( the cell’s outer surface those vesicl...)NIH Researchers Discover How Insulin Allows Entry of Glucose Into Cells

The researchers made their observations using a technique known as total internal reflector florescent microscopy. The technique consists of aiming a laser beam at an angle at the glass cover slip beneath the microscope, explained the last author of the paper, Vadim A. Frolov, Ph.D., of NICHD’s Laboratory of Cellular and Molecular Biophysics and the Russian Academy of Science in Moscow. The light bounces off the cover slip, away from the microscope’s lens. However, residual energy from the light passes through the cover slip, to the cell beneath, illuminating the area just below the cell’s surface while leaving the inside of the cell dark.

“When we started the experiment, we thought that the vesicles would be stationary,?Dr. Zimmerberg said. “The vesicles looked like comets streaking by.?/p>

Dr. Zimmerberg added that studying the chemical steps of the process in which the vesicles fuse with the cell membrane might yield a new drug to treat insulin-related disorders. He added that each step in the process might provide the basis for a treatment: when the vesicles first stop moving, when they tether to the inside of the cell’s membrane, and when they fuse with the membrane.

Next, the researchers plan to observe cells taken from mice having conditions resembling human disorders of insulin metabolism. Eventually, the researchers hope to obtain cell samples from volunteers who have been diagnosed with type 2 diabetes and insulin resistance.