A device to study the role of red blood cells in pulmonary hypertension has been developed by researchers in the US.

Scott Martin and colleagues from Saint Louis University have developed a microchip that can be used to mimic the smallest blood vessels in the circulatory system. Martin has used the device to explore the link between red blood cell deformation and the blood vessel widening.

In pulmonary hypertension, the arteries in the lungs become constricted, leading to an abnormally high blood pressure. Vasodilation, where the vessels in the lungs expand and allow blood to move through with less resistance, can counteract this. Nitric oxide is a potent vasodilator and is produced when ATP is released from cells.

Martin used the microchip to deform red blood cells and found that, as their deformation increased, they released more ATP. In the light of this, Martin suggests that the chip 'will greatly benefit researchers studying the role that erythrocytes [red blood cells] play in pulmonary hypertension.'

In collaboration with Dana Spence of Wayne State University in the US, Martin will implement his strategy in a US National Institutes of Health sponsored project to develop a blood-brain barrier mimic. The aim is to allow in vivo measurements to be made in both the bloodstream and the neural system and to ensure that drug candidates can cross the blood-brain barrier. The method used in Martin's microchip allows red blood cells to be focused to capillary dimensions, which is difficult to do with current methods, said Spence. 'Martin's model incorporates a feature that is missing from most blood-brain barrier models, namely, the blood flow itself.'

Elinor Richards