Strategy for prevention of myonephropathic metabolic syndrome (MNMS): comparison of cooling and perfusion

To evaluate the usefulness of cooling and perfusion methods for acute ischemic legs, we performed the experimental study using adult mongrel dogs. As creation of acute ischemic legs, the abdominal aorta was cross-clamped below the renal arteries, where all branches were ligated, for 6 hours. After release of clamp, the various parameters were examined for 18 hours. All dogs were divided into four groups according to the suppressive methods.

cross-clamping for 6 hours with no suppressive method, Group 1: cooling legs using crushed ice during 6 hour-clamping, Group 2: perfusion by heparinized saline of 2.5-10.0 ml/kg before declamping, Group 3: cooling during latter half of 6-hour clamping and perfusion same as Group 2. The serum levels of metabolites and the tissue pressure of the thigh showed significantly lower in the suppression groups than CONTROL GROUP after declamping. In addition, GOT, CPK and aldolase revealed significantly lower values in Group 3 than Group 2. The tissue blood flow of the thigh recovered to the same extent as before ischemia in Groups 2 and 3, while it did not so in CONTROL GROUP and Group 1. Microscopic findings in hematoxylin and eosin (H-E) staining indicated a marked destruction of muscle fiber and interstitial edema in the striated muscle in CONTROL GROUP. These changes were not found so much in Group 2, and almost no changes in Group 1 and 3. The immunostaining for Mb in the striated muscle showed negative in CONTROL GROUP and Group 2, while it showed positive staining in Groups 1 and 3. The immunostaining for Mb in the kidneys showed the most dense deposits of Mb in the renal tubules in CONTROL GROUP. These changes were less in Group 2, little in Group 3, and no change in Group 1. In conclusions, cooling method revealed the minimal metabolic change, and combined method with perfusion was still more effective for prevention of MNMS.