Acute response of peripheral CC r5 chemoreceptor and NK cells in individuals submitted to a single session of low‐intensity strength exercise with blood flow restriction

Summary The purpose of this study was to compare the peripheral expression of natural killers and CCR 5 in a session of low‐intensity strength training with vascular occlusion and in high‐intensity training. Young males were randomized into session groups of a high‐intensity strength training ( HI ) and a session group of low‐intensity strength training with vascular occlusion ( LI ‐ BFR ). The exercise session consisted in knee extension and bicep curl in 80% 1 RM ( HI ) and 30% 1 RM ( LI ‐ BFR ) with equalized volumes. Blood collection was made before, immediately after and 24 h after each training session. Immunophenotyping was carried out through CD 195+ ( CCR 5) e CD 3‐ CD 16+ CD 56+ ( NK ) in peripheral blood and analysed by flow cytometry and presented in frequency (%). Peripheral frequency of NK cells showed no significant difference in LI ‐ BFR group in time effect, while a gradual reduction of NK cells was identified in HI group in before‐24 h postexercise and after‐24 h postexercise comparison. However, significant differences have been found in relative change of NK cells immediately after exercise between sessions. In addition, HI and LI ‐ BFR groups showed a significant reduction in the cells expressed CCR 5 during 24 h postsession compared to the postsession, but CCR 5 also differed when comparing before‐24 h after session in the HI group. No differences were observed amongst the groups. LIO induced CCR 5 response similar to the HI session, while the NK cells remained in similar frequency during the studied moments in LI ‐ BFR , but not in HI group, suggesting that local hypoxia created by the blood flow restriction was able to prevent a change in the frequency of peripheral cells and a possible immunosuppression.