The inhibitory effect of lysozyme on the glomerular basement membrane thickening in spontaneous diabetic mice (NSY mice).

Currently, there is no effective treatment for diabetic microangiopathy. We have been examining, therefore, the effects of lysozyme on the renal conditions of spontaneous diabetic mice (NSY mice). We assessed the changes in glomerulus following the administration of lysozyme, using the thickness of the glomerular capillary basement membrane as an indicator. Littermate, male F19 NSY mice were divided into two groups. One of the groups (Group L) was treated with lysozyme; the other control group (Group C) with physiological saline. Group L received a daily intramuscular injection of lysozyme solution for 4 or 8 weeks. The thickness of the glomerular capillary basement membrane was measured in order to assess the effect of lysozyme administration. In the 4-week series, the thickness was 4783 +/- 1760 A in Group C and 3266 +/- 777 A in Group L, while in the 8-week series it was 6011 +/- 2043 A in Group C and 3540 +/- 431 A in Group L. In both series of Group L, a distinct inhibitory effect on the basement membrane thickening was found. The present findings suggest that lysozyme may be effective in human diabetic nephropathy. However its clinical usefulness must be confirmed in future studies.