Activity of lysosomal hydrolases in plasma at term and post partum

Abstract

The activity and isoenzyme pattern in plasma of beta-hexosaminidase (abbreviated Hex) and four other lysosomal hydrolases (alpha-fucosidase, beta-glucuronidase, alpha-hexosaminidase, alpha-mannosidase) were studied in 50 women at term and in 10 women at various intervals during the first 6 days after parturition. All hydrolases had elevated activity at term, compared with controls. After parturition the activity of alpha-mannosidase returned to the normal level within 2 days and that of Hex, beta-glucuronidase, and alpha-hexosaminidase within 6 days; alpha-fucosidase having a slightly elevated activity even at the end of this period. Isoenzyme analysis by isoelectric focusing was informative only in the case of Hex. Thus, the increased activity of Hex at term was mainly due to an increase in the isoenzyme form(s), with pI(s) between 5.6 and 6.8. The enzyme pattern of Hex during pregnancy and post partum observed in this study seems to have certain similarities to the previously noted enzyme pattern of Hex in acute ethanol intoxication and following withdrawal of ethanol. As lysosomal membranes are labilized by elevated levels of steroids, it is of interest to note that high levels of these hormones are found in plasma both at term and in chronic liver disease.