Enzymes of lysosomal origin in the serum of infants of diabetic mothers : behavior in the 1st days after birth

The serum levels of the two enzymes of lysosomal origin, β-N-acetyl-D-glucosaminidase and β-D-glucuronidase, and the isozyme pattern of the former, were determined in control infants and in infants of diabetic mothers (IDM) on the 1st and 5th day after birth. IDM were divided into three groups. Group 1: class A diabetic mothers treated dietetically; Groups 2 and 3: class A and classes B, C, D diabetic mothers, respectively, treated with insulin. All, but one, diabetic mothers were in excellent metabolic control. In the controls the serum levels of both enzymes were quite elevated on the 1st day after birth, reflecting the condition of the mothers at the end of pregnancy, and increased further on the 5th day, presumably as a result of the concurrent burst of antiinsulin hormones. In Group 1 IDM the serum levels of the two enzymes were higher than in controls, on the 1st day, probably reflecting the higher concentrations present in the mothers at the end of pregnancy than in controls, but equalling the condition of normal neonates on the 5th day. This indicates that IDM of this group had a normal post-natal response of the lysosomal apparatus to hormone stress. In Groups 2-3 IDM the enzyme levels on the 1st day could not be distinguished from those of controls, while on the 5th day a decrease was seen, suggesting reduced effect of the antiinsulin hormone burst on the lysosomal apparatus. The isozyme pattern of β-N-acetyl-D-glucosaminidase in all IDM was similar to that of controls. The behavior of serum lysosomal enzymes of Groups 2-3 IDM is a further indication that the lysosomal apparatus is extremely sensitive to even small metabolic perturbations occurring in diabetic mothers during pregnancy.