To most people, it probably looks like a nondescript bump on a line graph and a fuzzy picture of some distant planet, but to three Australian researchers it represents exciting research about the red blood cells that keep the other 60 trillion cells of the human body in working order.
This work on understanding the shape and function of red blood cells is fundamental research into physiology that is likely to provide a better
understanding of the human body. Amongst other potential applications, research of this type could open the way to finding new ways to tackle circulatory and respiratory disorders.
Australian Nuclear Science and Technology Organisation (ANSTO) physicist Dr Chris Garvey, in collaboration with two University of Sydney researchers, Professor Philip Kuchel and Dr Peter Mulquiney, has been directing neutron beams from the High Flux Australian Reactor (HIFAR) at blood cells and collecting the results.
The work has been supported by the Australian Institute of Nuclear Science and Engineering, the organisation that facilitates the use by Australian universities of the major national research facilities operated by ANSTO.
One of the components of red blood cells of interest to the researchers is haemoglobin - the protein that gives blood its red colour and performs the vital role of transporting oxygen around the body. The latest data has been able to show what the best microscopes cannot see how haemoglobin clusters within cells.
Dr Garvey explains that when we inhale, oxygen molecules are absorbed across the lining of the lung, through the blood plasma and into the red blood cells, which carry the oxygen to where it will be released and used by the body. "Our bodies have an extremely sophisticated way of turning up or down this ability to release oxygen to parts of the body that require it in differing amounts.
The hypothesis I am proposing is that the clustering of haemoglobin helps the red blood cell to deliver oxygen to where it is needed," Dr Garvey said. "When neutrons are directed through a sample of actively metabolising red blood cells, a pattern of concentric rings appears on the detector at the rear of the Small Angle Neutron Scattering (SANS) instrument. These rings are produced by neutrons interacting with clusters of haemoglobin molecules within the red blood cells. The intensity of these rings indicates what proportion of haemoglobin molecules are clustered inside the red blood cells," he said.
"My work has shown that the intensity of the ring is a function of cell volume. Because the surface area of the membrane which holds haemoglobin inside red blood cells is more or less constant, a change in volume must involve a change in shape. We are seeking a better understanding of the shape of these blood cells."
Dr Garvey, who regularly donates his own blood for this research, performs a range of neutron scattering experiments at HIFAR. Neutron scattering, the process of investigating the structure of matter by using neutrons, was the subject of the 1994 Nobel Prize for Physics, and will be a major function of the Replacement Research Reactor at Lucas Heights.