Science / Medicine : Hormone Link Seen to Diseases

Test-tube studies have shown that a genetically engineered brain hormone, called brain-derived neurotrophic factor or BDNF, can stimulate the growth of the two types of brain cells whose degeneration has been linked to Parkinson’s and Alzheimer’s disease. The discovery could lead to the development of new drugs for the treatment of the diseases, USC neurobiologist Franz F. Hefti reported last week in the Proceedings of the National Academy of Sciences.

Current drug therapy for the disorders seeks to replace missing neurotransmitters, while tissue transplants represent an attempt to replace dead cells with new ones. BDNF could be complementary because it seems to block the degeneration of existing nerve cells.

Hefti has shown that a related hormone, called nerve growth factor or NGF, can stimulate the growth of brain cells in living rats. But NGF also stimulates growth of nerve cells outside the brain, which could lead to unwanted side effects. BDNF, in contrast, seems to stimulate only nerve cells within the brain and thus should have a more selective action.