Studies on cartilage formation XXL Activity of enzymes belonging to the pentose-phosphate cycle in the regenerating articular surface

The distal articular surface of the femur was removed operatively in 36 dogs. In the regenerating chondrifying articular surface and in the granulation tissue adhering to the capsule glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase activities were determined 7, 33 and 70 days after operation. In both tissues the activity of these enzymes characteristic of the pentose phosphate cycle ws the highest in the early postoperative stage. This initial increase in activity was followed by a marked reduction in the regenerating articular surface and by a moderate decrease in the tissue adhering to the capsule. For the loss in activity occurring in the chondrifying articular surface, the connective tissue cells (fibroblasts) are responsible. Cartilage precursors and young chondrocytes show a high glucose-6-phosphate dehydrogenase and 6-phosphogluconate activity. Presumably, in the given case of the functions of the pentose-phosphate cycle the NADPH generation and supply of building stones prevail. The activity of these enzymes ws determined in the articular cartilage and in the synovial membrane of the knee joint in further 18 dogs. The activity in the articular cartilage was very slight as compared to that in the synovial membrane.     

The glucuronyl C5-epimerase activity is the limiting factor in the dermatan sulfate biosynthesis.

An early step in the biosynthesis of dermatan sulfate is polymerization to chondroitin, which then is modified by the D-glucuronyl C5-epimerase and mainly 4-O-sulfotransferase. The final structure of the dermatan sulfate side chains varies and our aim was to identify, which of the two enzymes that are crucial to generate dermatan sulfate copolymeric structures in tissues. Dermatan sulfate side chains of biglycan and decorin were prepared from fibroblasts and nasal and articular chondrocytes and characterized regarding detailed structure. Microsomes were prepared from these cells and the activities of D-glucuronyl C5-epimerase and 4-O-sulfotransferase were determined. Chondrocytes from nasal cartilage synthesized biglycan and decorin containing 10%, articular chondrocytes 20--30%, and fibroblast 80% of the uronosyl residues in the l-iduronyl configuration. All three tissues contained high amount of 4-O-sulfotransferase activity. The activity of d-glucuronyl C5-epimerase showed different relationships. Fibroblasts contained a high level of the epimerase activity, articular chondrocytes intermediary activity, and in nasal cartilage it was barely detectable. The data indicate that the activity of the d-glucuronyl C5-epimerase is the main factor for formation of dermatan sulfate in tissues.     

Histochemical evidence of a functional heterogeneity in neonatal canine epiphyseal chondrocytes

Synopsis The chondrocytes of the neonatal proximal humeral chondroepiphyses of twelve purebred English pointer pups were investigated histochemically, using frozen serial sections, for chondroitin sulphate and for the following enzyme activities: lactate dehydrogenase, NAD and NADP transhydrogenases, glutamate dehydrogenase, isocitrate dehydrogenase, malate dehydrogenase, glucose-6-phosphate dehydrogenase, ATPase, succinate dehydrogenase, and UDPgalactose 4-epimerase. By using Alcian Blue with and without a prior digestion in testicular hyaluronidase, and Alcian Blue in the presence of 0.9 M magnesium chloride, it was found that about half the chondrocytes stained as if they were producing significant amounts of chondroitin sulphate. Only one enzyme, UDPgalactose 4-epimerase (which is involved in the biosynthesis of chondroitin sulphate), was found to have a similar staining heterogeneity. Therefore, it was concluded that the chondrocytes studied possessed a functional heterogenicity with particular reference to chondroitin sulphate synthesis while appearing morphologically homogeneous.     

Experimental analysis of gossypol and chloroquine interaction in serum and in liver of rat.

Interactive effects of gossypol and chloroquine as determined by activities of serum alanine transaminase (ALT), aspartate transaminase (AST) and liver lactate dehydrogenase (LDH), alkaline phosphatase (ALK-pase), glucose-6-phosphatase (G-6-pase) and cholesterol level were investigated in rats. Administration of gossypol for eight weeks, at a concentration of 20 mg per kg body wt. per day with or without chloroquine had no effect on the serum enzymes and glucose-6-phosphatase activities. When chloroquine at a concentration of 5 mg per kg body wt. thrice a week was administered alone, there was a marked decrease in total protein content and ALK-pose activities, while a significant increase in LDH activity was observed. Administration of either gossypol or chloroquine decreased the level of cholesterol. A greater decrease was recorded when both were given together. It is suggested that gossypol can be employed as a male contraceptive among malaria-infected populations.     

Influence of several metabolites on A4 and B4-isoenzymes of loach lactate dehydrogenase activity depending on the direction of the isoenzyme-catalyzed reaction

Various concentration of fructose-1.6-diphosphate, malate, oxaloacetate, creatine phosphate, ATP, ADP and AMP were studied for their effect on the activity of A4-and B4-isoenzymes of lactate dehydrogenase (LDH, EC 1, 1. 1. 27) produced from skeletal muscles and unfertilized egg cells of Misgurnus fossilis in the reactions of lactate oxidation and pyruvate reduction. It was found that oxaloacetate, creatine phosphate, ADP and AMP decreased the activity of A- and B-type isoenzymes to a different extent. The value of the inhibitory action depended not only on the concentration of the substances and subunit composition of the isoenzymes but also depended on the direction of the reaction they catalyse. Malate and fructose-1.6-diphosphate did not inhibit the activity of A4 isoenzyme in the lactate oxidation and malate and ATP did not influence the activity of the former and of B4-isoenzymes in this reaction. At the same time malate, fructose-1.6-diphosphate and ATP decreased the activity of the investigated isoenzymes in the pyruvate reduction reactions.     

Enzyme activity profiles in an overwintering population of freeze-tolerant larvae of the gall fly,Eurosta solidaginis

The activity of some enzymes of intermediary metabolism, including enzymes of glycolysis, the hexose monophosphate shunt, and polyol cryoprotectant synthesis, were measured in freeze-tolerant Eurosta solidaginis larvae over a winter season and upon entry into pupation. Flexible metabolic rearrangement was observed concurrently with acclimatization and development. Profiles of enzyme activities related to the metabolism of the cryoprotectant glycerol indicated that fall biosynthesis may occur from two possible pathways: 1. glyceraldehyde-phosphate glyceraldehyde glycerol, using glyceraldehyde phosphatase and NADPH-linked polyol dehydrogenase, or 2. dihydroxyacetonephosphate glycerol-3-phosphate glycerol, using glycerol-3-phosphate dehydrogenase and glycerol-3-phosphatase. Clearance of glycerol in the spring appeared to occur by a novel route through the action of polyol dehydrogenase and glyceraldehyde kinase. Profiles of enzyme activities associated with sorbitol metabolism suggested that this polyol cryoprotectant was synthesized from glucose-6-phosphate through the action of glucose-6-phosphatase and NADPH-linked polyol dehydrogenase. Removal of sorbitol in the spring appeared to occur through the action of sorbitol dehydrogenase and hexokinase. Glycogen phosphorylase activation ensured the required flow of carbon into the synthesis of both glycerol and sorbitol. Little change was seen in the activity of glycolytic or hexose monophosphate shunt enzymes over the winter. Increased activity of the -glycerophosphate shuttle in the spring, indicated by greatly increased glycerol-3-phosphate dehydrogenase activity, may be key to removal and oxidation of reducing equivalents generated from polyol cryoprotectan catabolism.Abbreviations 6PGDH 6-Phosphogluconate dehydrogenase - DHAP dihydroxy acetone phosphate - F6P fructose-6-phosphate - F6Pase fructose-6-phospha-tase - FBPase fructose-bisphosphatase - G3P glycerol-3-phosphate - G3Pase glycerol-3-phosphate phophatase - G3PDH glycerol-3-phosphate dehydrogenase - G6P glucose-6-phosphate - G6Pase glucose-6-phosphatase - G6PDH glucose-6-phosphate dehydrogenase - GAK glyceraldehyde kinase - GAP glyceraldehyde-3-phosphate - GAPase glyceraldehyde-3-phosphatase - GAPDH glyceraldehyde-3-phosphate dehydrogenase - GDH glycerol dehydrogenase - GPase glycogen phosphorylase - HMS hexose monophosphate shunt - LDH lactate dehydrogenase - NADP-IDH NADP⁺-dependent isocitrate dehydrogenase - PDHald polyol dehydrogenase, glyceraldehyde activity - PDHgluc polyol dehydrogenase, glucose activity - PFK phosphofructokinase - PGI phosphoglucoisomerase - PGK phosphoglycerate kinase - PGM phosphoglucomutase - PK pyruvate kinase - PMSF phenylmethylsulfonylfluoride - SoDH sorbitol dehydrogenase - V _max maximal enzyme activity - ww wet weight     

Regulation of carbohydrate metabolism by indole-3-carbinol and its metabolite 3,3′-diindolylmethane in high-fat diet-induced C57BL/6J mice

Indole glucosinolates, present in cruciferous vegetables have been investigated for their putative pharmacological properties. The current study was designed to analyse whether the treatment of the indole glucosinolates—indole-3-carbinol (I3C) and its metabolite 3,3′-diindolylmethane (DIM) could alter the carbohydrate metabolism in high-fat diet (HFD)-induced C57BL/6J mice. The plasma glucose, insulin, haemoglobin (Hb), glycosylated haemoglobin (HbA1c), glycogen and the activities of glycolytic enzyme (hexokinase), hepatic shunt enzyme (glucose-6-phosphate dehydrogenase), gluconeogenic enzymes (glucose-6-phosphatase and fructose-1,6-bisphosphatase) were analysed in liver and kidney of the treated and HFD mice. Histopathological examination of liver and pancreases were also carried out. The HFD mice show increased glucose, insulin and HbA1c and decreased Hb and glycogen levels. The elevated activity of glucose-6-phosphatase and fructose-1,6-bisphosphatase and subsequent decline in the activity of glucokinase and glucose-6-phosphate dehydrogenase were seen in HFD mice. Among treatment groups, the mice administered with I3C and DIM, DIM shows decreased glucose, insulin and HbA1c and increased Hb and glycogen content in liver when compared to I3C, which was comparable with the standard drug metformin. The similar result was also obtained in case of carbohydrate metabolism enzymes; treatment with DIM positively regulates carbohydrate metabolic enzymes by inducing the activity of glucokinase and glucose-6-phosphate dehydrogenase and suppressing the activity of glucose-6-phosphatase and fructose-1,6-bisphosphatase when compared to I3C, which were also supported by our histopathological observations.     

Dietary and hormonal regulation of some enzyme activities associated with gluconeogenesis in rabbit liver.

1. Starvation increases the activity of cytosolic P-enolpyruvate carboxkinase in rabbit liver some 4-5 fold but does not alter the activities of mitochondrial P-enolpyruvate carboxykinase, fructose-1,6-diphosphatase or glucose-6-phosphatase.2. Alloxan-induced diabetes increases the activities of cytosolic P-enolpyruvate carboxykinase, fructose-1,6-diphosphatase and glucose-6-phosphatase approx. 6-, 2- and 2-fold, respectively. Again the activity of mitochondrial P-enolpyruvate carboxykinase is not altered. 3. Administration of mannoheptulose rapidly increases blood glucose levels and also causes a significant increase in cytosolic P-enolpyruvate carboyxkinase activity within 4 h. The activities of mitochondrial P-enolpyruvate carboxykinase, fructose-1,6-diphosphatase and glucose-6-phosphatase are not affected. 4. Administration of hydrocortisone also increases blood glucose levels and the activities of cytosolic P-enolpyruvate carboxykinase and glucose-6-phosphatase are significantly increased within 12h. Again, mitochondrial P-enolpyruvate carboxykinase and fructose-1,6-diphosphatase activities remain unaffected. 5. The observations that (A) the activity of cytosolic P-enolpyruvate carboxykinase responds to more situations conducive to gluconeogenesis than do the activities of mitochondrial P-enolpyruvate carboxykinase, fructose-1,6-diphosphatase and glucose-6-phosphatase, and (B) cytosolic P-enolpyruvate carboxykinase activity is rapidly adaptive under appropriate circumstances, suggests that this particular enzyme's activity plays an important role in the regulation of gluconeogenesis in rabbits.     

Studies on cartilage formation. XXII. Investigations of certain oxidative metabolic processes in regenerating articular cartilage

The distal articular surface of the femur was surgically removed in 57 dogs. Succinate dehydrogenase and cytochrome oxidase activities were assayed on postoperative days 7, 20, 26, 33 and 70 in the regenerating, chondrifying articular surface and in the granulation tissue adhering to the capsule. In the 70-day samples, the cyanide-induced inhibition of oxygen consumption was determined and enzyme histochemical reactions (cytochrome oxidase, monoamine oxidase, xanthine oxidase, peroxidase and "catalase") were performed. The succinate dehydrogenase activity was the highest in the early postoperative stage in both tissues. This was followed by a definite decrease and a subsequent significant increase in activity when chondrification took place. Measurement of cytochrome oxidase activity could not reveal any convincing result, presumably because of the properties of the tissues studied. The oxygen consumption by the chondrifying articular surface at 70 days was inhibited to about 50% by cyanide, and about 90% inhibition was observed in the tissue adhering to the capsule. The cells of the regenerating articular surface possess cytochrome oxidase and a cyanide- (and sodium azide-) resistant oxidase activity. The enzyme activity of the cartilaginous islets exceeded that of their connective tissue environment. The cytochrome oxidase activity increased in the cells during cartilage differentiation. Presumably, some further cyanide-sensitive and cyanide-resistant oxidases are present in chondroblasts and young chondrocytes.     

Efficacy of Citrus reticulata and Mirazid in treatment of Schistosoma mansoni

This work has been carried out to investigate the effect of Schistosoma mansoni infection on mice livers after treatment with the ethanolic extract of Citrus reticulata root or the oleo-resin extract from Myrrh of Commiphora molmol tree (Mirazid), as a new antishistosomal drug. Marker enzymes for different cell organelles were measured; succinate dehydrogenase (SDH); lactate dehydrogenase (LDH) and its isoenzymes; glucose-6-phosphatase (G-6-Pase); acid phosphatase (AP) and 5'- nucleotidase. Liver function enzymes; aspartate aminotransferase (AST); alanine aminotransferase (ALT), and alkaline phosphatase (ALP) were also estimated. Parasitological studies through ova count and worm burden will also be taken into consideration. The results showed a marked reduction in SDH, LDH, AST, and ALT enzyme activities and a significant increase in G-6-Pase, AP, 5'- nucleotidase, and ALP after S. mansoni infection. A noticeable alteration in LDH subunits were also noticed. Treatment with C. reticulata or Mirazid improved all the previous enzyme activities with a noticeable reduction in ova count and worm burden.     

Isolation, Biochemical Characterization, Long-Term Culture, and Phenotype Modulation of Oval Cells from Carcinogen-Fed Rats

Oval cells are liver epithelial cells that proliferate during hepatocarcinogenesis and chemically induced severe liver injury. It has been suggested that these cells represent hepatic stem cells which might play an important role in the histogenesis of cholangiocellular as well as hepatocellular carcinomas. In order to test this hypothesis highly purified oval cell preparations and propagable oval cell lines are needed. In the present study the isolation, biochemical characterization, and longterm culture of oval cells from rats fed a choline-deficient/DL-ethionine-supplemented diet for 6, 14, or 22 weeks are described. The freshly isolated oval cells were γ-glutamyltranspeptidase-positive, cytokeratin 7-, 8-, 18-, and 19-positive, albumin-positive, peroxidase-negative, and α-fetoprotein-negative and expressed lactate dehydrogenase isoenzymes 1-5. In addition, low but clearly measurable glucose-6-phosphatase and high γ-glutamyltranspeptidase and alkaline phosphatase activities (when compared to activities in untreated liver parenchymal cells) were measured in oval cells. Three oval cell lines, OC/CDE 6, OC/CDE 14, and OC/CDE 22, were established. They contained small and large epithelial cells replicating to form uniform monolayers with a cobblestone appearance; furthermore, a very low number of mononucleated giant cells were also present in the three cell lines. OC/CDE 6, OC/CDE 14, and OC/CDE 22 cells were γ-glutamyltranspeptidase-negative, were transiently albumin-positive, maintained the glucose-6-phosphatase activity levels measured in freshly isolated oval cells, and expressed lactate dehydrogenase isoenzymes 2-5. After exposure of the cultured oval cells to dimethyl sulfoxide or sodium butyrate, 35-40% of the cells reexpressed albumin, and glucose-6-phosphatase activity was enhanced; in addition, sodium butyrate strongly increased γ-glutamyltranspeptidase and alkaline phosphatase activities. In conclusion, oval cells express phenotypic markers of liver parenchymal as well as bile duct epithelial cells and possess a certain intrinsic plasticity. In order to test if the oval cells indeed represent an intermediate step in the differentiation of certain cells within the bile duct and ductular epithelial cell compartment to parenchymal cells, the three cell lines described herein will be transformed in vitro and their potential to give rise to cholangiocellular and/or hepatocellular carcinomas will be verified in vivo.     

Histochemical studies on the albino rat pancreas in different periods following vagotomy and simultaneous pyloromyotomy.

The effect of complete subphrenic vagotomy and simultaneous pyloromyotomy on the morphological state and the activities of some intracellular enzymes of the albino rat was studied histochemically. Within the first weeks after vagotomy, the pancreatic acini were found to diminish in size, and the beta-cells in the islets of Langerhans became oedematous. In the acini, the activities of succinate dehydrogenase, cytochrome oxidase, AS naphthol acetate esterase, and glucose-6-phosphatase were observed to decline, but the reactions for beta-glucuronidase and aryl sulphatase showed intensifications and polymorphic behaviour both in acinar and in islet cells. The latter also and particularly the beta-cells simultaneously revealed enhanced activities of succinate dehydrogenase, cytochrome oxidase, beta-glucuronidase, and aryl sulphatase, and an entire disappearance of the reaction for glucose-6-phosphatase. The alpha-cells increased their AS naphthol acetate esterase activity. After 5 weeks following vagotomy, morphological and enzymatic changes in the acini and islets were negligible, and after 5 and 9 months no differences were noted between the vagotomized rats and the control animals.     

Lactate dehydrogenase isoenzymes are present in matrix vesicles

Matrix vesicles were isolated from epiphyseal growth plates of young rabbits. Lactate dehydrogenase activity was detected in the isolated matrix vesicles only in the presence of detergents, suggesting that NADH, the cofactor for the assay, does not penetrate the membrane of matrix vesicles. In contrast, the activity of alkaline phosphatase, a marker enzyme of the outer surface of matrix vesicles, was detected in the matrix vesicles using p-nitrophenyl phosphate as the substrate both in the presence and absence of detergents. Lactate dehydrogenase activity was detected only in the cytosol of chondrocytes of the epiphyseal growth plates but not in other subcellular fractions, showing that lactate dehydrogenase is not from the plasma membrane and membranes of intracellular organelles of chondrocytes. The isolated matrix vesicles contained all five lactate dehydrogenase isoenzymes but did not possess other cytosolic enzymes. These results show that lactate dehydrogenase is located in the matrix vesicles and suggest the presence of a mechanism for the specific uptake of cytosolic lactate dehydrogenase and the possibility of enzymatic quantification of the matrix vesicles at various calcification sites.     

Effect of tuftsin on the activity of energy metabolism enzymes in peritoneal macrophages

Cytochemistry was used to measure the activity of succinate dehydrogenase (SOD), lactate dehydrogenase (LDH) and glucose-6-phosphate dehydrogenase (G-6-PDH) in rat peritoneal macrophages under the action of the endogenous immunostimulant tuftcin (tre-lys-pro-arg) during phagocytosis of latex particles and at rest. Tuftcin did not affect the activity of the study enzymes in non-phagocytic cells. Elevation of the peptide concentration to 0.25 micrograms/ml and higher in phagocytic macrophages activated G-6-PDH and lowered the activity of LDH. Tuftcin did not alter the activity of SOD in phagocytic macrophages.     

Distribution of cartilage molecules in the developing mouse joint.

This study describes the precise spatial and temporal patterns of protein distribution for aggrecan, fibromodulin, cartilage oligomeric matrix protein (COMP) and cartilage matrix protein (CMP) in the developing mouse limb with particular attention to those cells destined to form articular chondrocytes in comparison to those cells destined to form a mineralized tissue and become replaced by bone. Mouse glenohumeral joints from fetal mice (12-18 days post coitus (dpc) to the young adult (37 days after birth) were immunostained with antibodies specific for these molecules. Aggrecan staining defined the general chondrocytic phenotype, whether articular or transient. Fibromodulin was associated with prechondrocytic mesenchymal cells in the interzone prior to joint cavitation and with the mesenchymal cells of the perichondrium or the periosteum encapsulating the joint elements of the maturing and young adult limb. Staining was most intense around developing articular chondrocytes and much less abundant or absent in those differentiating cells along the anlage. CMP showed an almost reciprocal staining pattern to fibromodulin and was not detected in the matrix surrounding articular chondrocytes. COMP was not detected in the cells at the articular surface prior to cavitation but by 18 dpc, as coordinated movement of the mouse forelimb intensifies, staining for COMP was most intense around the maturing articular chondrocytes. These results show that the cells that differentiate into articular chondrocytes elaborate an extracellular matrix distinct from those cells that are destined to form bone. Fibromodulin may function in the early genesis of articular cartilage and COMP may be associated with elaboration of a weight-bearing chondrocyte matrix.     

Undifferentiated patterns of key carbohydrate-metabolizing enzymes in injured livers. II. Human viral hepatitis and cirrhosis of the liver.

Activities of key carbohydrate-metabolizing enzymes were determined on biopsied liver tissues obtained from patients with acute and chronic viral hepatitis and postnecrotic cirrhosis of the liver. The results indicated that the activities of fetal or prototype enzymes, low-Km hexokinases, glucose-6-phosphate dehydrogenase and pyruvate kinase type M2 increased, while those of adult type liver enzymes, glucokinase, glucose-6-phosphatase, fructose-1, 6-diphosphatase and pyruvate kinase type L decreased in livers of these cases. Phosphofructokinase activity tended to increase only acute hepatitis. Principal component analysis revealed that the enzyme patterns of acute hepatitis and liver cirrhosis were most deviated from the control and closely resembled those of hepatocellular carcinomas.     

Enzymatic characterization of the pancreatic islet-specific glucose-6-phosphatase-related protein (IGRP)

Glucose is the main physiological stimulus for insulin biosynthesis and secretion by pancreatic beta-cells. Glucose-6-phosphatase (G-6-Pase) catalyzes the dephosphorylation of glucose-6-phosphate to glucose, an opposite process to glucose utilization. G-6-Pase activity in pancreatic islets could therefore be an important factor in the control of glucose metabolism and, consequently, of glucose-dependent insulin secretion. While G-6-Pase activity has been shown to be present in pancreatic islets, the gene responsible for this activity has not been conclusively identified. A homolog of liver glucose-6-phosphatase (LG-6-Pase) specifically expressed in islets was described earlier; however, the authors could not demonstrate enzymatic activity for this protein. Here we present evidence that the previously identified islet-specific glucose-6-phosphatase-related protein (IGRP) is indeed the major islet glucose-6-phosphatase. IGRP overexpressed in insect cells possesses enzymatic activity comparable to the previously described G-6-Pase activity in islets. The K(m) and V(max) values determined using glucose-6-phosphate as the substrate were 0.45 mm and 32 nmol/mg/min by malachite green assay, and 0.29 mm and 77 nmol/mg/min by glucose oxidase/peroxidase coupling assay, respectively. High-throughput screening of a small molecule library led to the identification of an active compound that specifically inhibits IGRP enzymatic activity. Interestingly, this inhibitor did not affect LG-6-Pase activity, while conversely LG-6-Pase inhibitors did not affect IGRP activity. These data demonstrate that IGRP is likely the authentic islet-specific glucose-6-phosphatase catalytic subunit, and selective inhibitors to this molecule can be obtained. IGRP inhibitors may be an attractive new approach for the treatment of insulin secretion defects in type 2 diabetes.     

X chromosome expression during oogenesis in the mouse.

The activities of glucose-6-phosphate dehydrogenase (G6PD) and lactate dehydrogenase (LDH) have been assayed in mouse oocytes at several stages of follicle development isolated from XX and XO female mice. Throughout the entire growth period the activity of G6PD was proportional to the number of X chromosomes present in the oocyte, whereas no difference in LDH activity was detected between XX and XO oocytes. It is concluded, therefore, that both X chromosomes are functional throughout oogenesis.     

Histochemical enzyme pattern of microfilaria of Setaria cervi

The present study deals with the histochemical localization of glucose-6-phosphatase, malic dehydrogenase and aldolase in the microfilaria of Setaria cervi. Marked activity of glucose-6-phosphatase was observed in the cephalic cells, excretory and anal pores, G-cells and Innenk?rper. Malic dehydrogenase activity was noted throughout the body (including cuticle) of the microfilaria except for Innenk?rper. Intense aldolase activity was observed in the excretory pore and G-cells only. Muscle cells and anal pore were negative for this enzyme.     

Undifferentiated patterns of key carbohydrate-metabolizing enzymes in injured livers. I. Acute carbon-tetrachloride intoxication of rat.

In acute CCL4 intoxication of rats significantly increased activities of hepatic low-Km hexokinases, glucose-6-phosphate dehydrogenase, phosphofructokinase, aldolase A and pyruvate kinase M2 with concurrently decreased activities of glucokinase, glucose-6-phosphatase, fructose-1,6-diphosphatase, aldolase B and pyruvate kinase L were observed. The resulting enzyme pattern was apparently different from that in dietary induction. Principal component analysis revealed that the degree of enzyme deviation in the injured liver was much greater than that in the regenerating liver after partial hepatectomy and was closer to that in fetal liver or hepatoma tissue.