Proceedings of The Physiological Society

Europhysiology 2018 (London, UK) (2018) Proc Physiol Soc 41, PCA348

Poster Communications

Evidence of a physiological perfusion balance between human limb pairs

C. J. Rocha1, H. Silva1,2, H. A. Ferreira3, L. Monteiro Rodrigues1,2

1. CBIOS/ECTS, Universidade Lusofona, Lisboa, Lisboa, Portugal. 2. Faculty of Pharmacy, Pharmacol. Sc Depart, Universidade de Lisboa, Lisboa, Lisboa, Portugal. 3. Faculty of Sciences - Institute of Biophysics and Biomedical Engineering, Universidade de Lisboa, Lisboa, Lisboa, Portugal.

A particular perfusion dynamic, responsible for a circulatory steady state between both hind limbs has been described in human, regarded as a long-term vascular adaptation to ischemia in patients with peripheral arterial occlusive disease. More recently, similar observations were described in the human foot as a consequence of postural vasoconstriction, and in the mouse during hyperoxia following a hindlimb ischemia. In the present study we approach the effect of massage, a well known technique, over this apparent balance. A group of 29 young healthy subjects (19.9 ± 1.56 y.o.), both sexes (16 female, 13 male), body mass index (BMI)< 24.9 kg/m2 and ankle-brachial index (ABI) of 1.06, were selected from previously outlined inclusion and non-inclusion criteria. All procedures complied with the Helsinki Declaration principles and subsequent amendments. Subjects were submitted to a massage protocol consisting of three phases - a 10 minute stabilisation (Phase I), a 5 minute massage in one randomly selected limb (Phase II) and 10 minute recovery (Phase III). The contralateral limb served as control. Perfusion was assessed in both limbs by laser Doppler flowmetry (LDF) and photoplethysmography (PPG), and signals decomposed by the wavelet transform (WT) into their main spectral bands (cardiac, respiratory, myogenic, sympathetic, endothelial NO dependent and endothelial NO independent). Respiratory rate (RR), pulse rate (PR) and blood pressure (BP) were also quantified. Descriptive and comparative statistics were (p< 0.05). A perfusion increase was detected in both limbs by LDF and PPG during massage, statistically significantly in the massaged limb. The WT from both technologies showed a decrease in the cardiac, sympathetic and in the endothelial components, as well as an increase in the respiratory and myogenic components. The observed perfusion increase might then involve an increase in myogenic and a decrease in sympathetic activities, prevailing over the observed decrease of endothelial activities. Therefore, WT analysis seems to be useful to further explore complex signals such as LDF and PPG, but more importantly, the confirmed increase in the contralateral foot induced by single limb massage confirms the referred particular dynamics between human hind limbs, likely intended to preserve the lower limb circulatory homeostasis.

Where applicable, experiments conform with Society ethical requirements