ABSTRACT
Photobiomodulation therapy (PBMT) can be applied to the whole body as compared to the application of using single hand-held devices that isolate a smaller muscle area. The purpose of this study was to examine the effects of an acute dose of whole-body PBMT pre- and post-high-intensity resistance training on creatine kinase (CK) and salivary interleukin-6 (IL-6) in a sample of trained males. Twelve males (31 ± 8.3 years, 177.2 ± 5.4 cm, and 86.0 ± 7.5 kg) were part of a randomized, counterbalanced, cross-over design, whereby each participant performed a high-intensity resistance training session that consisted of the bench press, chin-up, and repeated sprints on two separate occasions. Each participant was assigned to either the PBMT or control condition on two separate weeks, with a 10-days washout period between the weeks. Creatine kinase was measured at baseline, 24, 48, and 72 h post-exercise. Salivary IL-6 was measured at baseline, 60, 90, and 120 min. A paired t-test showed no significant difference (p = 0.669) in the area under the curve (AUC) for CK during the PBMT (191.7 ± 48.3) and control conditions (200.2 ± 68.0). A Wilcoxon signed-rank test also showed no significant median difference (p = 0.155) in the AUC for salivary IL-6 during the PBMT (Mdn = 347.7) and control conditions (Mdn = 305.8). An additional Wilcoxon signed-rank test for CK percentage change from 24 to 72 h showed the PBMT condition (Mdn = -45%) to have a -18% median difference as compared to the control condition (Mdn = -41%). As such, whole-body PBMT does not significantly reduce the activity of salivary IL-6 or CK concentration during the 24 to 72-h recovery post-high-intensity resistance training.
ABSTRACT
OBJECTIVE: To determine meropenem concentrations in radiocarpal (RC) joint fluid and plasma after intravenous regional limb perfusion (IVRLP). STUDY DESIGN: In vivo experimental study. ANIMALS: Nine healthy adult mares. METHODS: Meropenem (500 mg) was injected in the forelimb of standing sedated horses via IVRLP with a pneumatic tourniquet inflated to 400 mmHg. Synovial fluid was collected from RC joints at 0, 0.5, 1, 2, 4, 6, 8, 12, and 18 hours after meropenem injection. Blood samples were collected from the jugular vein at the same time points and at 5 and 15 minutes following injection. Meropenem concentrations were determined by using a microbiological bioassay. RESULTS: Median synovial fluid concentrations reached a time of maximum synovial fluid concentration 0.5 hours after IVRLP. Synovial fluid concentrations varied greatly, with a mean maximum synovial fluid concentration of 25.6 µg/mL (range, below limit of quantitation to 75.5). Concentrations remained above the breakpoint for susceptibility (1 µg/mL) for 3 hours (last nonzero concentration measured, median) and 4.1 hours (predicted, mean). Concentrations >6 µg/mL were measured for 2 hours (observed, median) and 1.7 hours (predicted, mean). Six horses had mild swelling at the injection site. CONCLUSION: Administration of 500 mg meropenem resulted in highly variable concentrations between horses and achieved levels above clinically relevant minimum inhibitory concentration for a minor portion of a once-daily dosing interval. CLINICAL SIGNIFICANCE: If time-dependent pharmacodynamics apply, IVRLP with 500 mg of meropenem may be ineffective and would likely promote resistance.
