Observations on the histochemically demonstrable liver glycogen phosphorylase activity and native glycogen under different nutritional conditions

Summary In this study a histochemical demonstration of glycogen phosphorylase activity and native glycogen in the livers from normally fed, overfed and starved rats was performed.It was found that the amount and localization of phosphorylase activity well corresponded to the amount and localization of the native glycogen. A change of the glycogen content in the liver also resulted in a change of the histochemically demonstrable liver glycogen phosphorylase activity.It is concluded that the presence of tissue bound glycogen and undissolved glycogenphosphorylase complexes are necessary for positive histochemical demonstration of liver glycogen phosphorylase activity.This work was supported by a grant from the Finnish Veterinary Medical Foundation.     

Effect of ischemia-reperfusion on the heterogeneous lobular distribution pattern of glycogen content and glucose-6-phosphatase activity in human liver allograft.

In order to examine glucose metabolism in liver grafts after cold ischemia and reperfusion, the heterogeneous lobular distribution pattern of glycogen content and glucose-6-phosphatase activity was studied using histochemical methods. The characteristic heterogeneous lobular distribution pattern of glycogen and glucose-6-phosphatase was maintained after preservation and reperfusion. However, it appeared that glycogen content decreased in both periportal and centrilobular hepatocytes after reperfusion. The glycogen decrease was higher in periportal hepatocytes. Glucose-6-phosphatase activity was maintained after reperfusion in most of the cases in periportal hepatocytes. In centrilobular hepatocytes, more cases showed a decrease in enzyme activity. It is suggested that ischemia-reperfusion mainly affects the glycogen content in both periportal and centrilobular hepatocytes and that centrilobular glucose-6-phosphatase activity is more sensitive to ischemia-reperfusion injury than periportal hepatocytes.     

Histochemistry of the glycogen body of the turkey spinal cord

Summary Enzyme histochemical studies of the glycogen body of the turkey showed very little activity of suocinic dehydrogenase and cytochrome oxidase in the glycogen body cells, and marked activity of lactic dehydrogenase, NAD-diaphorase and the hexosemonophosphate shunt enzymes. Gradients of histochemical staining intensity for lactic and succinic dehydrogenase in the glycogen body and spinal cord were confirmed by biochemical assays of homogenates of these tissues. It was concluded that glycogen body metabolism is predominantly glycolytic. Alkaline phosphatase activity was weak; acid phosphatase activity was moderate. There was no acetyl cholinesterase or nonspecific cholinesterase activity in the glycogen body.This investigation was supported by U. S. Public Health Grant B 3250.Submitted in partial fulfillment of Masters' degree requirements.     

The appearance and degradation of specific hepatocellular cytoplasmic inclusion bodies in rat liver due to D-galactosamine. I. The relation between the amount of liver glycogen and the appearance of the atypical dense bodies in the liver cell.

One of the most sensitive and specific signs of the galactosamine effect upon the rat liver cell is the appearance of PAS-positive and diastase-resistant granules within the cytoplasm of hepatocytes. Light-microscopic, histochemical, biochemical, and electron-microscopic findings reveal that the appearance of these ADB (= atypical dense bodies) depends upon a working glycogen metabolism at the time of GalN treatment. The ADB are composed of particles resembling, due to shape and size, ribosomes and beta particles of glycogen. Most of them are surrounded by the rER, but they are never enclosed by a limiting membrane. Due to sequential changes they can be generally classified into three types; the early, the intermediate, and the late type. In seven experiments it can be shown, that the appearance of the ADB depends upon the time and dosage after GalN treatment. They occur even if an additional treatment with galactose or uridine prevents the liver from the features of a hepatitis, as also shown in the livers of newborn animals up to 3 weeks of age. The histochemical response against various glucosidases, hexosaminidases, pronase, and RNAse as well as against various fixatives indicates that ADB are composed of, at least, two different constituents, the former RNAse-sensitive and visible with routine light-microscopic staining procedures, the latter RNA-resistant, PAS-positive, and invisible after staining with H & E or toluidine blue. The latter is diastase-resistant, suggesting that this portion of ADB does not represent the usual glycoproteins but some abnormal metabolite of glycogen. The ADB can be detected with maximal accumulation in the cytoplasm of hepatocytes at that time when the glycogen content determined in the liver homogenate by biochemical methods is greatly reduced.     

Histochemical demonstration of rat liver glycogen phosphorylase activity with iron (Fe++)

Summary A new histochemical method for light microscopic demonstration of liver glycogen phosphorylase activity has been introduced in this study.The method demonstrates phosphorylase activity by precipitating phosphate ions, liberated in the reaction catalyzed by the enzyme, with Fe⁺⁺ present in the incubating medium. The precipitate is visualized as ferrous sulphide.The new glycogen, formed in the same reaction, can also be demonstrated in this method after staining with iodine.The lobular localization of the reaction products obtained according to this method in the liver, corresponds well to that obtained according to earlier methods for the demonstration of only new-formed glycogen.     

Electron microscopical study of a cytosolic enzyme in unfixed cryostat sections: demonstration of glycogen phosphorylase activity in rat liver and heart tissue

Summary Glycogen phosphorylase activity has been demonstrated at the ultrastructural level in liver and heart tissue of fasted rats. Unfixed cryostat sections were incubated by mounting them on a semipermeable membrane stretched over a gelled incubation medium. The medium contained a high concentration of glucose 1-phosphate which enables indirect detection of glycogen phosphorylase activity on the basis of the synthesis of glycogen. Tissue fixation, dehydration and embedding for electron microscopical study were performed after the incubation had been completed. The ultrastructure of both liver and heart tissue was rather well preserved. Glycogen granules resulting from glycogen phosphorylase activity were found in the cytoplasmic matrix of both hepatocytes and cardiomyocytes; no relationship with membranous structures could be detected. It is concluded that the semipermeable membrane method is well suited for localizing cytosolic enzyme activities at the ultrastructural level without prior tissue fixation; this opens further perspectives for correlations between histochemical and biochemical data.     

Zum histochemischen Phosphorylasenachweis im Herzinfarkt

Summary The demonstration of glycogen by PAS-method and the reaction of phosphorylase by Takeuchi et al. were performed in the hearts of rats 30 min after experimental coronary occlusion. While the cardiac muscle cells in the center of the ischemic region still contained glycogen, the cells in the border zone of the infarction did not. The phosphorylase activity was demonstrable only in those cardiac muscle cells which contained glycogen. As well known that the demonstration of phosphorylase activity is possible only if glycogen as starter is present, it is concluded that the lack of phosphorylase activity by the histochemical reaction in cells which do not contain glycogen doesn't prove the absence of the enzyme.

---

---

Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.

---

Stipendiat der Alexander von Humboldt-Stiftung.     

A brachial glycogen body in the spinal cord of the domestic chicken.

When cervical segments 14 to 15 of the chicken spinal cord are cut transversely and studied by routine histological and histochemical methods, an onion-shaped region, filled with thread-like fibers, is seen to surround the ependymal cells of the central canal and to be bounded laterally by the neural elements of the spinal gray matter. This area is negative for succinic dehydrogenase, beta-hydroxybutyrate dehydrogenase and cholinesterase activity, but very strongly periodic acid-Schiff positive. Diastase controls show the positive material to be glycogen. Parasagittal sections through this cervical region and into the upper thoracic cord, show the glycogen-rich region to extend longitudinally throughout the region. Because of its location and histochemical characterization, which are similar to that of the ventral portion of the glycogen body, the term brachial glycogen body is proposed for this structure.     

Changes in the acinar distribution of some enzymes involved in carbohydrate metabolism in rat liver parenchyma after experimentally induced cholestasis

Extrahepatic cholestasis induced by ligation and transsection of the common bile duct caused a change in the parenchyma/stroma relationship in rat liver. Two weeks after ligation, the periportal zones of the parenchyma were progressively invaded by expanding bile ductules with surrounding connective tissue diverging from the portal areas. Parenchymal disarray developed and small clumps of hepatocytes or isolated hepatocytes were scattered within the expanded portal areas. These cells showed normal activity of lactate, succinate and glutamate dehydrogenase and may, therefore, be considered to be functionally active. After cholestasis the remainder of the liver parenchyma showed adaptational changes with respect to glucose homeostasis, as demonstrated by histochemical means. Glycogen stores disappeared completely whereas glycogen phosphorylase activity increased about ten fold. The increased glycogen phosphorylase activity and glycogen depletion indicate a greater glycogenolytic capacity in liver parenchyma after bile duct ligation to maintain as far as possible a normal plasma glucose concentration. The parenchymal distribution pattern of glucose-6-phosphatase activity did not change significantly after bile duct ligation. The isolated hepatocytes within the expanded portal tracts showed a high activity of this enzyme whereas the pericentral parenchyma was only moderately active. The distribution patterns of glucose-6-phosphate dehydrogenase and lactate dehydrogenase activity in the liver parenchyma were also largely unchanged after bile duct ligation, but the histochemical reaction for glucose-6-phosphate dehydrogenase activity demonstrated infiltration of the remainder of the parenchyma by non-parenchymal cells, possibly Küpffer cells and leucocytes as part of an inflammatory reaction. Under normal conditions the mitochondrial enzymes succinate and glutamate dehydrogenase show an opposite heterogenous distribution pattern in liver parenchyma. Following cholestasis both enzymes became uniformly distributed. The underlying regulatory mechanism for these different changes in distribution patterns of enzyme activities is not yet understood.     

The effects of glucose and of potassium ions on the interconversion of the two forms of glycogen phosphorylase and of glycogen synthetase in isolated rat liver preparations.

In the isolated perfused rat liver, increasing glucose concentration from 5.5 to 55 mm in the perfusion medium caused a sequential inactivation of glycogen phosphorylase and activation of glycogen synthetase. The latter change was preceded by a lag period which corresponded to the time required to inactivate the major part of the phosphorylase. 2. The same sequence of events was observed in isolated rat hepatocytes incubated at 37C. In this preparation, the rate of phosphorylase inactivation was greatly increased by increasing the concentration of glucose and/or of K+ ions in the external medium. The same agents also caused the activation of glycogen synthetase, but this effect was secondary to the inactivation of phosphorylase. 3. In both types of preparations, the rate of synthetase activation was modulated by the residual amount of phosphorylase a that remained after the initial phase of rapid inactivation and was independent of glucose concentration. 4. In isolated hepatocytes, the rate of conversion of glucose into glycogen was propotional to the activity of synthetase a in the preparation. This conversion was preceded by a lag period which could be shortened by increasing either glucose or K+ concentration in the medium. The incorporation of labelled glucose into glycogen was simultaneous with a glycogenolytic process which could not be attributed to the activity of phosphorylase a.     

Glycogen phosphorylase hyperactive foci of altered hepatocytes in aged rats

In untreated 12- to 24-month-old rats, the enzyme histochemical pattern of 45 focal hepatic lesions was investigated in serial sections. In addition to previously characterized glycogen storage foci, a new type of enzymatically altered hepatic focus was found. The outstanding feature of this was an increased glycogen phosphorylase activity. The frequent appearance of glycogen phosphorylase hyperactive foci simultaneously exhibiting excessive glycogen storage suggests a close relationship to the well known glycogen storage foci representing an early stage in the sequence of cellular changes which lead to hepatic tumors.     

Morphochemical investigations of the liver and biochemical studies of the blood of guinea pigs in anaphylactic shock

The experimental investigations have been carried out on 116 guinea pigs divided in two groups: the experimental and control group. The animals of the experimental group were sensitized with a 25% egg white suspension in 0.86% conc. of NaCl applied subcutaneously. After 21 days the same animals were exposed to the action of the same antigen in aerosol according to the method of Gerszanowicz, [16]. It has been shown, that in anaphylactic shock (acute and chronic) the damage of the lysosomal membranes in hepatocytes appeared which may be the cause of liberation among others also of acid phosphatase from the liver into the blood. Histochemically it was found a low phosphorylase and glucose-6-phosphatase activity, which was the basis of the assumption, that in anaphylactic shock we have to do with an enzymatic block--phosphorylase kinase--phosphorylase and inhibition of the enzymatic activity of glucose-6-phosphatase in the liver of guinea pigs. The comparison of the histochemical and biochemical results concerned with the amount of lipids, glycogen and nucleic acids in the liver revealed that the increasing amount of lipids is paralleled by decrease of glycogen. Among nucleic acids a growing level of ribonucleic acid was found while the level of the desoxyribonucleic acid remained stable.     

Polysaccharide synthesis in tissue sections

Summary Biochemical methods for demonstration of enzyme activity are test tube models outside the organization of cell. Their application to the complicated organization of the cell present problems to histochemistry. The morphological and chemical preservation of tissue which is desirable in histochemistry leads to a multiplicity of reactions when test tube methods are applied. For example, the histochemical phosphorylase and glycosyltransferase reactions rest on the assumption that one can distinguish between preexisting glycogen and newly formed polysaccharides. We used frozen dried canine myocardium and liver for examination of the authenticity of histochemical phosphorylase and glycosyltransferase (branching enzyme, UDPG-glycogen transglycosylase) reactions as described in histochemical reference books. We were unable to distinguish between preexisting glycogen and supposedly newly formed polysaccharides with methods presently used for this purpose (Iodine stain, differential digestion with amylases, acid hydrolysis). Tissue without PAS stainable glycogen remained so after substrate incubation. When preexisting glycogen was present, the amounts of stainable polysaccharides after incubation were invariably less. Therefore, we could not prove beyond doubt that any polysaccharide synthesis due to enzyme reaction had oceured. The prescribed controls, perhaps adequate for biochemical test tube reactions, have to be redefined for meaningful histochemical procedures.This work was supported by grant number HE-07605-07 from the National Heart Institute, National Institutes of Health, Bethesda, Md., U.S.A.     

The effect of ischemia on glycogen phosphorylase activity in rat liver: a quantitative histochemical study

The effects of ischemia in vitro for 0-60 min at 37 degrees C on glycogen phosphorylase activity in rat liver have been studied under different feeding conditions. Glycogen phosphorylase activity was demonstrated with a recently developed quantitative histochemical method using a semipermeable membrane and the PAS-reaction. The cytophotometrically measured glycogen phosphorylase activity in livers from 24 h-fasted rats was approximately five times the activity in livers from normally fed rats. The activity in periportal areas was about 1.5 times higher than the activity in pericentral areas in livers from starved rats, but more or less evenly distributed in livers from fed rats. Enzyme activity in pericentral areas of livers from 24 h-fasted rats started to decrease after 20 min of ischemia. After 50-60 min of ischemia, the activity was decreased to approximately 25% of the control activity. Livers from normally fed rats showed unchanged activity in periportal and pericentral areas after 10-60 min of ischemia. It has been assumed that the activation of the enzyme was disturbed by ischemia, possibly as a consequence of plasma membrane damage.     

实验性肝癌糖原和癌基因N-ras表达的研究

通过应用原位杂交和组织化学技术,对二乙基亚硝胺诱发的大鼠肝细胞肝癌中糖原和癌基因Ｎ－ｒａｓ表达的研究,发现从诱癌早期到晚期,肝细胞内的糖原由储积而逐渐丧失。Ｎ－ｒａｓ在诱癌的第１～２周即出现阳性表达,随诱癌过程的延长,阳性表达的细胞数和范围逐渐增加,至诱癌晚期甚至在癌结节内均转为阴性。对肝组织连续切片中糖原和Ｎ－ｒａｓ表达的对比观察发现,糖原ＰＡＳ反应与Ｎ－ｒａｓ反应同步,糖原ＰＡＳ反应具有与Ｎ－ｒａｓ一致的异质性,其阳性与阴性病变分布与Ｎ－ｒａｓ表达重叠。提示Ｎ－ｒａｓ基因表达可能在肝癌的启动过程中发挥重要作用,并且可能涉及对糖原基因的调控。     

Glycogen metabolism in human fetal testes

The ontogeny of glycogen synthetase, glycogen Phosphorylase and α-D-glucosidase, enzymes which are associated with glycogen metabolism and glycogen level has been studied in human fetal testes of gestational age ranging from 14–32 weeks. Glycogen synthetase activity reaches the peak value at 17–20 weeks of gestation, thereafter it decreases. α-D-Glucosidase activity increases with the advancement of pregnancy up to 28 weeks of gestation decreasing thereafter very rapidly. Phosphorylase activity remains more or less constant throughout gestation. The maximum increase in glycogen content at early stages of gestation (17–20 weeks) and gradual reduction with the advancement of pregnancy are correlated with histochemical observation by the periodic acid-Schiff technique.     

Lesions of skeletal muscles in rats with acute alcoholic intoxication

Histological and histochemical studies of the rat skeletal muscles in acute alcohol intoxication have revealed metabolic disturbances, characterized by a decreased glycogen level, small-drop fatty infiltration, decreased activity of aerobic and enhanced activity of anaerobic enzyme glycolysis, dystrophic and focal necrotic myocyte changes. Acute alcohol intoxication in fasting animals is accompanied by more pronounced dystrophic and necrotic myocyte changes, decreased glycogen and lipid content.     

Activation of hepatocyte glycogen synthase by metabolic inhibitors

Incubation of isolated rat hepatocytes with metabolic inhibitors causes an increase in the -glucose 6-P/+glucose 6-P activity ratio of glycogen synthase after decreasing ATP and increasing AMP levels. Concomitantly, the activity of phosphorylase is increased six-fold by the same treatment. This activation of both enzymes remains after gel filtration of the hepatocyte extracts. Addition of metabolic inhibitors to cells pretreated with an inhibitor of AMP-deaminase results in an accumulation of AMP and, simultaneously, in a further increase in the activation state of glycogen synthase. The correlation coefficient between the intracellular concentration of AMP and glycogen synthase activity is r = 0.93. It is proposed that the covalent activation of glycogen synthase by metabolic inhibitors can be triggered by changes in the level of the intracellular concentrations of adenine nucleotides.     

Nuclear Localization of Brain-type Glycogen Phosphorylase in Some Gastrointestinal Carcinoma

Our previous reports have demonstrated frequent and strong expression of glycogen phosphorylase (EC 2.4.1.1) activity mainly in the cytoplasm of gastric carcinoma. Although previous studies have suggested the phosphorylase glyco-syltransferase system to be in the nucleus from enzyme histochemical analyses, intranuclear localization of the phosphorylase has not been fully established. The aims of the present study are to investigate the nuclear localization of glycogen phosphorylase and to identify the isoform of phosphorylase in the nucleus of gastrointestinal carcinoma. The activity of glycogen phosphorylase in carcinoma cells corresponding to the nucleus was demonstrated using enzyme cytochemical analysis. The phosphorylase activity coincided with localization revealed by immunocytochemistry using affinity-purified specific anti-human brain-type glycogen phosphorylase antibody. The isoform expressed in the nuclei of carcinoma cells was identified as bei ng only the brain type according to a polymerase chain reaction-based assay using RNA obtained from gastric carcinoma cells and primers specific to muscle, liver and brain types of glycogen phosphorylase. The intranuclear localization of the brain-type isoform was confirmed by immunoelectron microscopical analyses. Further investigation to examine the nuclear localization in human carcinoma tissue (145 and 25 specimens with gastric and colonic carcinoma respectively) was carried out by immunohistochemistry using specific anti-brain-type antibody. Nuclear immunostaining was observed in seven cases out of 145 gastric carcinoma. The present study is the first to clarify the nuclear localization of glycogen phosphorylase with enzymatic activity in gastrointestinal carcinoma. The isoform of the enzyme expressed in the carcinoma was identified as the brain type. These results warrant further studies on the mechanisms for transporting the large molecule of brain-type glycogen phosphorylase to nuclei and its function in the nucleus of carcinoma cells.     

Histochemical fiber type distribution and epinephrine sensitivity in normal and cross-transplanted rat muscles

The metabolic integrity of fully regenerated transplants was investigated by measuring induced changes in glycogen concentration. The extensor digitorum longus and the soleus muscles were cross transplanted: the extensor digitorum longus into the soleus muscle bed (SOLT) and the soleus muscle into the extensor digitorum longus bed (EDLT). The histochemical fiber type distribution of the regenerated muscles was determined and was found to transform in cross-transplanted EDLT and SOLT. After transplantation and regeneration, both muscles had initially low glycogen concentrations. However, the EDLT glycogen concentration was not significantly different from that of the contralateral extensor digitorum longus control muscle after 60 days. In the SOLT, glycogen gradually increased but remained less than in the contralateral soleus control muscle. SOLT and control soleus muscles responded with a significant glycogen depletion to an epinephrine dose two orders of magnitude less than the lowest dose affecting glycogen levels in EDLT and extensor digitorum longus muscles. These results indicate that transplanted muscles are capable of regenerating normal glycogenolytic responses and that the sensitivity of the response observed depends on the site of transplantation and is related to the type of innervation and histochemical fiber type.