Fig. 2. This protocol was performed to assess effects of catheter implantation (cell injury) alone with respect to time on local intramuscular lactate and lactate/pyruvate ratios, assuming normal saline effect is negligible. Briefly, six microdialysis catheters were implanted percutaneously into adductor muscles of the right and left thighs (three catheters in each thigh) of malignant hyperthermia–susceptible (MHS) or normal swine. Perfusion of the catheters with normal saline (without ryanodine receptor agonist) were started immediately 0, 5, 10, 20, 30, and 40 min after implantation of each catheter in the muscle. Dialysate fraction was collected for 10 min.  A and  B show lactate and lactate/pyruvate molar ratios, respectively. These data suggest that at least 30 min  in situ catheter equilibration is essential before the start of ryanodine receptor agonist perfusion. * Significantly higher than corresponding values in normal swine. # Significantly higher than 30- to 40-min data point in MHS group.