Follicles of the Future
Most men who lose their hair have a hereditary condition called androgenic alopecia, says Neil Sadick, M.D., Clinical Associate Professor in the Department of Dermatology at Cornell University Medical College. These men have increased levels of a hormone known as 5(alpha)-reductase, which changes testosterone to dihydrotestosterone (DHT). The DHT in turn causes follicles to sprout shorter and finer hairs before eventually dying out. It also causes the growth phases of hair follicles to become shorter, and the rest phases to be longer.
But researchers are discovering that this rest phase can be shortened. The October 1999 Journal of Clinical Investigation reported that scientists at the Weil Medical College of Cornell University succeeded in nudging hair follicles out of their rest phases -- at least in mice. They used an altered form of cold virus to deliver what they have named the "Sonic hedgehog" gene (after a video-game character), which plays a central role in hair follicle development. This therapy spurred the mice to sprout new hairs, presumably by causing those in the rest phase to enter the growth phase. Researchers say further study is needed before it is known if this therapy could potentially help those with male pattern baldness.
Lend Me Your Hair
Another potential treatment for balding was described in the November 1999 issue of Nature. Researchers found it was possible to grow hair follicles and hair from donated follicle cells.
Hair follicles are one of the few immunoprivileged parts of the body -- that is, they are protected from the immune system so the body doesn't treat them as foreign and attack them. Researchers thus wondered if they might be transplanted from one person to another without triggering an immune response and therefore rejection. Hair follicle cells, donated from the arm of a male scientist, were implanted into the arm of a female scientist. A few weeks later, she grew large, thick, dark hairs -- unlike her own -- in the area of the transplant.