beta-Hexosaminidase level in serum from patients with viral hepatitis as a measure of reticuloendothelial function

Utility and evaluation of biochemical markers of alcohol consumption

Biochemical markers of alcohol consumption have a variety of clinical and research applications. Currently available markers such as the serum gamma-glutamyl transpeptidase (GGT), serum transaminases, and the mean corpuscular volume (MCV) lack sufficient sensitivity and specificity to be used for screening of alcoholism in ambulatory patients. However, these tests can be helpful in corroborating a clinical suspicion of alcoholism. A number of special laboratory markers of alcoholism recently have been developed which may have increased diagnostic accuracy. Promising potential markers include serum carbohydrate-deficient transferrin (CDT), red blood cell acetaldehyde, and acetaldehyde adducts. The application of reliable and practical markers of alcohol consumption could lead to significant improvements in the treatment of alcoholism and in the assessment of clinical trials.

Clinical evaluation of serum N-acetyl-beta-D-glucosaminidase as a liver function test

Serum N-acetyl-beta-D-glucosaminidase has been shown to be a sensitive indicator of liver function. The enzyme activity in serum from patients with different forms of hepatic disease was found to be elevated. A comparison is also made with routine liver parameters. The frequencies of pathological serum levels of the routine measurements made are in relatively good agreement with earlier reports.

beta-Hexosaminidase in plasma and liver after partial hepatectomy in normal and cirrhotic rats

The liver and plasma level of the lysosomal enzyme beta-hexosaminidase was analyzed in partially (about 70%) hepatectomized rats with normal liver or carbon tetrachloride (CCl4)-induced cirrhosis. The enzyme level of the liver did not show marked changes after partial hepatectomy in either normal or cirrhotic rats. In contrast, the plasma basal level was significantly higher in cirrhotic rats and increased to a peak at 6 h, followed by a decrease to a minimum level 24 h after operation. The enzyme returned to its high plasma basal level at 36 h after partial hepatectomy, when the liver had recovered to 70% of its initial weight. In rats with normal liver the plasma beta-hexosaminidase showed another pattern, with a rapid increase at 6 h and thereafter gradually reaching a peak at 36 h after hepatectomy. We conclude that the cells responsible for increased plasma beta-hexosaminidase in cirrhotic rats are situated in the liver.

Tissue content and localization of lysosomal enzymes in cholestatic rats

Levels of the lysosomal enzymes beta-glucuronidase and beta-hexosaminidase were determined in tissues from rats at 1-7 weeks after permanent bile duct occlusion (28 animals) and sham operation (16 animals). With increasing duration of bile duct occlusion, increasing levels were found in the liver and spleen, whereas levels were unaffected in the pancreas, kidneys, brain, muscle, and skin. Histochemical investigation showed that the lysosomal enzymes accumulated in the hepatocytes and in the increasing numbers of reticuloendothelial cells of the liver and spleen during cholestasis. No significant accumulation of lysosomal enzymes was seen in the pancreas. In preparations of isolated hepatocytes and non-parenchymal cells increased specific activity of lysosomal enzymes in cholestasis appeared in both cellular fractions. It is assumed that the serum increase of lysosomal enzymes in late cholestasis is partly due to a release from activated macrophages in the liver and spleen.

Lysosomal enzymes, alkaline phosphatase, and bilirubin in plasma after bile duct transection in the rat

Plasma levels of the lysosomal enzymes beta-glucuronidase and beta-hexosaminidase were studied for 6 weeks after permanent bile duct occlusion (19 animals) or sham operation (5 animals). The bile duct-occluded animals had a stable bilirubinemia throughout the observation period. The median level of beta-glucuronidase in controls was 0.45 U/l. In jaundiced animals the median level was 1.09 at 0.5 weeks, 1.28 at 2 weeks, and 1.58 at 6 weeks after bile duct occlusion. The median level of beta-hexosaminidase in controls was 18.5 U/l. In jaundiced animals the median level was 18.0 at 0.5 weeks, 20.8 at 2 weeks, and 53.3 at 6 weeks after operation. Compared with beta-glucuronidase, prominent elevation of the beta-hexosaminidase level appeared much later after bile duct obstruction, which might suggest a closer association with reticuloendothelial system function for the latter enzyme.

Pattern of serum beta-hexosaminidase in liver cirrhosis

The activity of the primarily lysosomal hydrolase, beta-hexosaminidase (EC 3.2.1.30), was studied in serum from 53 patients with bleeding esophageal varices, portal hypertension, and liver cirrhosis (31 alcoholic, 13 cryptogenic, and 9 primary biliary). The serum enzyme activity was determined on 89 occasions and was increased in 93%. There was no difference in the distribution between the three patient groups, but in patients who underwent portal-systemic shunt surgery there was a significant increase after 9-12 months. Serum beta-hexosaminidase activity correlated significantly with other biochemical tests known to be influenced by portal-systemic shunting. It is concluded that determination of this enzyme might become a useful liver test, since it sensitively detects liver disease and also might be specific, since besides liver disease only pregnancy and lysosomal disorders are known to show considerable elevations in serum activity.