Narrator: This is Science Today. Type I diabetics don't make insulin, which is essential for life. In contrast, type II's make the stuff -- but their bodies just don't use it. That so-called insulin resistance is mainly in muscle tissue. Meanwhile, Dr. Robert Henry of the University of California, San Diego has found a way to keep muscle tissue alive in the laboratory for months at a time, giving him the perfect tool to study type II diabetic muscle.

Henry: We can compare it to normal muscle, non-diabetic muscle, and look at every step of the action between normals and diabetic muscle.

Narrator: Recent drugs seem to reverse insulin resistance -- but no one knows how. Henry feeds those drugs to his laboratory muscles.

Henry: And they do in fact become much more insulin-sensitive. And we are starting to look at why they are becoming more sensitive. What the mechanism is. Because ultimately if we can pinpoint it, we probably are going to be able to pinpoint the underlying defect, perhaps the genetic defect causing diabetes.

Narrator: For Science Today, I'm Steve Tokar.