Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: THURSDAY, August 12, 1993 TAG: 9308120076
SECTION: NATIONAL/INTERNATIONAL PAGE: A12 EDITION: METRO
SOURCE: Associated Press
DATELINE: NEW YORK LENGTH: Medium
Researchers found evidence that nitroglycerin and similarly acting drugs protect brain cells from an overstimulation that may play a role in those conditions as well as in Parkinson's, Huntington's and Lou Gehrig's diseases.
Animal studies also have shown evidence of a possible usefulness in stroke and AIDS dementia, said neurologist Dr. Stuart Lipton of Harvard Medical School and Children's Hospital in Boston.
But he said people should not take nitroglycerin for the brain conditions yet, because scientists have not found the proper dose to avoid a potentially serious drop in blood pressure. Nitroglycerin is normally used to treat angina pectoris, a heart condition.
Lipton and co-authors present the test-tube work in today's issue of the journal Nature.
They focused on a substance in the body called nitrogen monoxide. They found evidence that one form, called nitric oxide, can lead to death of brain cells, while another form, nitrosonium ion, protects brain cells. Either form can switch to the other under the proper chemical conditions, researchers said.
Nitroglycerin acts like the beneficial form, Lipton said in a telephone interview. It affects a protein structure on brain cells called the NMDA receptor, which receives chemical messages from neighboring brain cells. Lethal overstimulation of the NMDA receptor is implicated in damage from stroke and the other brain conditions, researchers said.
Nitroglycerin molecules appear to prevent overstimulation by attaching part of themselves to the NMDA receptor, Lipton said.
by CNB