Post Occlusive Reactive Hyperaemia (PORH)
The increase in microvascular blood flow following arterial occlusion, post occlusion reactive hyperaemia (PORH), can be assessed using the non-invasive laser Doppler technique. Following release of the arterial occlusion there is a marked transient increase in microvascular blood flow to the ischaemic tissues. Laser Doppler derived PORH measurements have been shown to be highly reproducible. The mechanisms behind PORH are believed to be a combination of: myogenic relaxation of the vessels, release of local mediators and metabolites from the ischaemic tissue, and more recently the involvement of sensory nerves. As a result of unknown mechanisms behind PORH there is extensive research in this area. Previous studies have shown the PORH response to ischaemia shows distinct patterns that are associated with cardiovascular risk i.e. area under curve (AUC) and peak flux following the period of ischaemia.
We recommend the moorVMS-VASC PC software to streamline the measurement and analysis together with a single or dual channel moorVMS-LDF monitor and multi-fibre skin probes (VP1T/7). The rapid deflation valve of the CUFF - Arm RD helps with rapid deflation so the hyperaemic response is maximised and the moorVMS-PRES provides automation of the cuff inflation/ deflation protocol.
Contact us to discuss your specific needs and to request your copy of our free Application Note which includes a detailed experimental method and practical suggestions. We also offer no obligation on-site visits so you can test the equipment in your facility.
Clough, G., Chipperfield, A., Byrne C., de Mul, F., Gush, R.G. (2009) Evaluation of a new high power, wide separation laser Doppler probe: Potential measurement of deeper tissue blood flow. Microvascular Research, 78 (2), pp 155-161
Minson, T., Lorenzo, S. (2007) Human Cutaneous reactive hyperaemia: role of BKCa channels and sensory nerves. Journal of Physiology, 585, pp 295-303 Patterson, G. C. (1956) The role of intravascular pressure in the causation of reactive hyperaemia in the human forearm. Clin Sci (Lond), 15 (1), pp 17-25
Strain W. D., Chatuvedi N., Bulpitt, C. J., Shore A. C. (2005) Albumin excretion rate and cardiovascular risk: could the association be explained by early microvascular dysfunction? Diabetes, 54 pp 1816-1822
Yamamoto-Suganuma R., Aso Y. (2009) Relationship between post-occlusive forearm skin reactive hyperaemia and vascular disease in patients with Type 2 diabetes – a novel index for detecting micro- and macrovascular dysfunction using laser Doppler flowmetry. Diabet Med 26, pp 83-88
Yvonne-Tee G. B., Rasool A. H. G., Halim, A. S., Rahman A. R. A. (2005) Reproducibility of different laser Doppler fluximetry parameters of postocclusive reactive hyperemia in human forearm skin. Journal of Pharmacological and Toxicological Methods, 52, pp 286-292.