Cholesterol Vital for Healthy Lung Function: Study

Sydney, April 15 (IANS) Cholesterol, the much-maligned bugbear of those concerned with obesity, might be vital to the healthy functioning of the lungs.

The discovery by University of South Australia (UniSA) could assist premature babies with breathing difficulties as well as help in transplant surgery.

Cholesterol plays a significant role in surfactant, a complex mixture of lipids (fats) and proteins lining the alveoli in the lungs that keep it saturated, humidified and warmed, said Sandra Orgeig of UniSA, who led the research team.

As the surfactant system and lungs are not fully developed in premature babies, they cause breathing difficulties and eventually collapse.

Air is then forced into these babies by ventilator. In severe cases, artificial surfactant is also administered by being vapourised and inhaled into their lungs.

"Our evolutionary studies show that no matter how simple or complex, every lung that inflates and deflates has surfactant and there are differences in its composition," said Orgeig.

The group's discovery that cholesterol is important in the surfactant system has prompted biomedical researchers worldwide to debate whether cholesterol should be incorporated as a component of artificial surfactants.

"While humans can't cope with body temperature changes, reptiles and certain groups of mammals can change their body temperature. Again the key is cholesterol.

"The fact that different fats can exist in different states at the same temperature reflects their different lipid composition, just like oil, which exists in liquid form in its coolest state when compared with butter which, at the same temperature is solid," Orgeig said.

"We know how important cholesterol is for body temperature changes in mammals. Now we are investigating this further to see if there is value in including cholesterol in artificial surfactants for premature babies or adults with severe respiratory distress.