A new oxygen delivery therapeutically restored the function of oxygenated cardiac tissue in an animal model of global hypoxia in…
A new oxygen delivery therapeutically restored the function of oxygenated cardiac tissue in an animal model of global hypoxia in new studies conducted at UC San Francisco. The study has been published in the Journal of PLOS Biology. For body tissues that run low on oxygen is a big danger, especially for the heart. Such hypoxic conditions can lead to prolonged tissue damage or even heart attacks.
The new drug, called OMX-CV, does not seem to cause systemic side effects or overruns with excessive oxygen activity in the blood, unlike its experimental predecessors, which themselves can be toxic. Instead, the new drug delivered its valuable oxygen fragment only to the tissues that most need it.
Emin Maltepe, co-author of the paper, said that any tissue with compromised blood flow, whether caused by trauma, stroke or heart disease, could potentially be targeted at such treatment.
Cardiovascular diseases such as coronary heart disease can starve the heart of oxygen, trigger cardiac dysfunction or heart attack in adults, but heart failure is also a problem in children. According to the Centers for Disease Control and Prevention Treatment (CDC), about 1
0,000 children are born annually with a critical congenital heart defect. In their first year of life, many of these infants need cardiac surgery, under which blood can be temporarily removed from the heart, leaving the organ starving to oxygen.
Under normal conditions, the heart consumes more oxygen than any other body, and when the oxygen level is low; Demand rises even higher. The hypoxic cardiac pumps are more difficult to deliver oxygen to the rest of the body and paradoxically require more and more oxygen to maintain the function. An oxygen-releasing drug such as OMX-CV may facilitate physical stress of hypoxia and improve recovery after heart attacks or after open heart surgery in adults and children.
Hemoglobin-based drugs have also proven to be too good for their jobs: they tend to flood the blood with excess acid that itself can cause serious tissue damage. Furthermore, when it is outside the boundary of a red blood cell, hemoglobin can capture nitrogen oxide, a natural muscle relaxant contained in the blood vessels. Vessels robbed of nitrogen oxide constrict, which causes blood pressure to jump, increase the risk of myocardial infarction and lower blood flow to important organs like the kidneys.
OMX-CV sidesteps these problems using a constructed bacterial protein called H-NOX as a base, rather than hemoglobin. H-NOX proteins contain a “co-factor” called a heme group – the same co-factor that gives hemoglobin its name – which means that the protein binds not only oxygen but also nitric oxide. By modifying the chemical structure of H-NOX proteins, omniox researchers re-engineered them to stick to oxygen, but leaving nitrogen oxide alone. The researchers also showed that the modified proteins bind oxygen so hard that they only refrain from their grip when they encounter a serious hypoxic tissue.
Published: October 20, 2018, 20:05