Molecule muscles more oxygen off haemoglobin to boost performance and beat heart failure
Sun, 15th Feb 2009
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from the show The Science of Love
Scientists have developed a new molecule that can provoke haemoglobin, the red oxygen-bearing pigment in blood, to release its oxygen cargo more readily, boosting muscle power.
Writing in this week's PNAS, Boston University Medical Centre researcher Andreia Biolo and her colleagues describe a new molecule ITPP - myo-inositol trispyrophosphate - which can mimic the way the body adapts to high altitude by penetrating red blood cells and locking onto the haemoglobin molecules inside. This causes the haemoglobin molecules to alter their shape slightly, loosening their grip on the oxygen molecules they pick up from the lungs. As a result the cells give up the oxygen far more readily to the tissues. Tests in healthy mice showed that ITPP-treated animals had 50% greater exercise endurance compared with their untreated littermates.
But even more encouragingly, when the agent was administered to animals with an inherited form of heart failure (a dilated cardiomyopathy), their capacity for exercise increased by 70% because the demands on the heart were lower because the animals' muscles were able to obtain the oxygen they needed at lower levels of blood flow. This, say the researchers, may be a highly effective way to improve the lives of patients disabled by heart failure, particularly since ITPP seems to be orally-active in the experimental mice. But they will, first, need to prove that the agent is safe first before human trials can begin.
- "Enhanced exercise capacity in mice with severe heart failure treated with a novel allosteric effector of hemoglobin, myo-inositol trispyrophosphate," by Andreia Biolo, Ruth Greferath, Deborah A. Siwik, Fuzhong Qin, Eugene Valsky, Konstantina C. Fylaktakidou, Srinivasu Pothukanuri, Carolina D. Duarte, Richard P. Schwarz, Jean-Marie Lehn, et al; PNAS; Feb 10, 2009; Vol. 106, No. 6; pp. 1926-1929