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The relation of diabetic control to in vivo pH of soft tissue abscesses
A N Bessman1, P J Geiger, L J Thomas
1Department of Medicine, Rancho Los Amigos-University of Southern California Medical Center, Downey.
Abstract:
It has been shown that induced soft tissue abscesses have a lower intra-abscess pH in the uncontrolled diabetic host than in the nondiabetic control. These differences were felt to be secondary to alterations in white cell metabolism. The current study compares the intra-abscess pH in three groups of mice: (I) nondiabetic, (II) untreated diabetic, and (III) insulin-treated diabetic. Diabetes was induced with streptozotocin in male white mice. The bacteria used to induce the abscesses were a combination of B. fragilis and Enterococcus. The blood glucose values of groups I, II, and III were 189 mg% (+/- 20.3), 256 mg% (+/- 121.9), and 712.8 mg% (+/- 169.7), respectively. None of the animals were ketotic, and peritoneal pH (reflecting systemic pH) showed no significant differences between groups. There were no significant differences in colony counts between any groups. The intra-abscess pH values of groups I, II, and III were 6.97 (+/- 0.26), 6.85 (+/- 0.41), and 6.08 (+/- 0.70). The differences in intra-abscess pH and blood glucose levels were all significantly different from each other when all three groups were compared. The insulin-treated mice tended to return to normality but had the widest spread of values. Since a decrease in intra-abscess pH has been felt to be a reflection of white cell activity, our studies may be the first to demonstrate an in vivo effect of insulin on white cell activity.
Insights
Diabetic mice with induced soft tissue abscesses show lower intra-abscess pH, indicating altered white cell metabolism. Insulin treatment in diabetic mice improved pH towards normal levels, suggesting an in vivo effect on white cell activity.
Area of Science:
- Infectious Diseases
- Endocrinology
- Immunology
Background:
- Uncontrolled diabetes is associated with impaired host defense mechanisms.
- Previous studies suggest lower intra-abscess pH in diabetic hosts, potentially due to altered white blood cell (WBC) metabolism.
Purpose of the Study:
- To compare intra-abscess pH in nondiabetic, untreated diabetic, and insulin-treated diabetic mice.
- To investigate the in vivo effect of insulin on WBC activity within abscesses.
Main Methods:
- Induced soft tissue abscesses in three groups of mice: nondiabetic, untreated diabetic, and insulin-treated diabetic.
- Diabetes was induced using streptozotocin; abscesses were infected with B. fragilis and Enterococcus.
- Measured blood glucose, peritoneal pH, intra-abscess pH, and bacterial colony counts.
Main Results:
- Intra-abscess pH was significantly lower in untreated diabetic mice (6.85) and insulin-treated diabetic mice (6.08) compared to nondiabetic controls (6.97).
- Blood glucose levels were significantly higher in untreated (256 mg%) and insulin-treated (712.8 mg%) diabetic mice compared to nondiabetic controls (189 mg%).
- Insulin treatment showed a trend towards normalizing intra-abscess pH but resulted in a wider range of values.
Conclusions:
- Diabetic status significantly impacts intra-abscess pH, likely reflecting altered WBC function.
- This study provides evidence for an in vivo effect of insulin on WBC activity in the context of infection.
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