Effect of organophosphate pesticide Sumithion (Fenitrothion) on some aspects of carbohydrate metabolism in a freshwater fish,Sarotherodon (Tilapia)mossambicus (Peters)

Summary A lethal (Lc₅₀/48 h — 6 mg/l) concentration of the organophosphate (OP) pesticide Sumithion increased blood glucose levels and phosphorylase activity, but hepatic glycogen registered a fall which indicated that the observed hyperglycemia was due to breakdown of hepatic glycogen.This work was supported by UGC grant to R.R.     

The electron microscopy of fluorescent dextrans (FITC-dextrans) in thin sections of tissue

Summary Fluorescein-coupled dextrans (FITC-Ds) were detected in sections in the electron microscope using 4 different contrasting methods when tissue was postfixed in osmium tetroxide. Endogeneous glycogen was also stained by the methods used, but FITC-D particles appeared smaller and more irregular, and in other locations. In dextranase treated specimens glycogen was still visible, while FITC-D was not.Acknowledgments. The author is grateful to Susan Max-Jacobsen, Kjeld Stub and Sonja Fich for excellent technical assistance. The author was supported by a research fellowship from the Danish Medical Research Council (12–1688).     

Brain glycogen following experimental cerebral ischemia in gerbils (Meriones unguiculatus)

Summary Cortical glycogen levels decreased after both 1 and 3 h of unilateral ischemia. After 1 h of recirculation, the levels of glycogen were restored to control values in both groups. Subsequently, glycogen increased above normal levels after 1 week of recirculation in the 1 h ischemic groups, and after 5 h in the 3 h ischemic group. Thus, the onset of the excess glycogen accumulation appears to be dependent on the intensity of the ischemic insult.     

Dial variations in the levels of blood glucose and hepatopancreatic glycogen in the slug,Laevicaulis alte (Ferussac 1821)

Summary InLaevicaulis alte maximal blood glucose level at 00.00 h alternates with minimal level at 12.00 h of the day, while hepatopancreatic glycogen showed an opposite trend. Variations in blood glucose levels are inversely proportional to the corresponding variations in hepatopancreatic glycogen content, while blood glucose level shoots up to a maximum, hepatopancreatic glycogen declines to a minimum and vice versa.Acknowledgment. The authors thank Prof. K.S. Swami for providing facilities. The financial assistance rendered by ICMR (DCR), UGC (VJ) and CSIR (KS), New Delhi, India is gratefully acknowledged.     

Effects of oral contraceptive steroids (norethisterone/mestranol) on the activities of hepatic drug-metabolizing enzymes in iron-deficient anemic rats

Either oral contraceptive steroid (norethisterone/mestranol; N/M) treatment or iron-deficiency (Fe(-] anemia alone caused an increase in NADPH cytochrome c reductase and in three hepatic microsomal mixed-function oxidase activities in female rats. When N/M treatment and the Fe(-) diet are combined, no further change in hepatic enzyme activity is seen compared with that with either treatment alone.     

Histochemical localization of acetylcholinesterase in the glycogen body (sinus rhomboidalis) of common brown dove,Streptopelia senegalensis and house sparrow,Passer domesticus

Summary Acetylcholinesterase (AChE) activity was studied in the glycogen bodies of the spinal cords of 2 birds namelyStreptopelia senegalensis andPasser domesticus. A possible functional significance of AChE in the light of relative enzymatic localization especially in Hoffmann-Kolliker nuclei (motor cell groups), substantia gelatinosa and other regions of gray matter of 2 avian glycogen bodies has been discussed.     

Regulation of carbohydrate metabolism by the optic tentacles of the garden snailCryptozona ligulata (Gastropoda-Stylommatophora)

Summary The presence of a hyperglycemic factor in the optic tentacles of the snailC. ligulata is reported here. A preliminary characterization based on crude extracts indicates the factor to be water-soluble, heat labile and to be an albumin. The ablation of optic tentacles and injection of optic tentacle extract into operated and normal snails caused a rise in blood sugar, total carbohydrate and glycogen in the foot muscle and mantle and a decrease in hepatopancreatic glycogen. The ablation also caused a fall in blood free amino acids and a rise in the tissues, which was reversed in the blood and foot muscle by injection of the extract. Possible conversion of amino acids to total carbohydrates and glycogen by gluconeogenesis is suggested.     

Frederick Pavy (1829-1911) and his opposition to the glycogenic theory of Claude Bernard

For more than 50 years the Guy's Hospital physician Frederick Pavy (1829-1911) attempted to discredit the theory of his erstwhile teacher, Claude Bernard, that liver glycogen was broken down to supply sugar to the systemic circulation. His opposition was driven by his clinical perceptions and was based on two assumptions: the first was that the kidney was a simple filter through which small molecules would diffuse, so that sugar had to be prevented from reaching the systemic circulation. For Pavy, the liver was the barrier. The second was teleological: he could not believe that nature would operate in what he saw as a defective way, i.e. converting sugar into glycogen and then back again. At the beginning of his long working life Pavy regarded himself as a physiologist and was critical of the stagnancy of English physiology which was kept afloat by amateurs like himself in whatever time they could spare from busy private practice. At the end he came to see his own view of carbohydrate metabolism as symbolic of the schism between responsible clinicians (himself) and irresponsible daydreaming physiologists (his opponents).     

Changes in serum proteins and in major liver constituents following carbon tetrachloride and a high-fat choline-free diet in rats.

Both carbon tetrachloride and a high-fat, low-protein choline-free diet cause hepatomegaly in rats due to an accumulation of both lipids and proteins with a concomitant increase in deoxyribonucleic acid content. CCl4 causes a decline in hepatic glycogen. Serum albumin level is decreased in CCl4-treated rats and increased in those fed the experimental diet.     

Hypersensitivity to endotoxin hepatotoxicity in rats with inflammatory lesions

Summary The ratio of sinusoidal nonparenchymal cells to hepatocytes in rat liver was significantly increased following induction of inflammation, and decreased after subsequent exposure to endotoxin, particularly in the region around the terminal portal venules. Rats with inflammatory lesions were more sensitive to endotoxin hepatocytotoxicity than normal controls, as judged from the dose-dependent increase in activity of serum transaminases and from the extent of liver tissue injury. In addition, these animals, which were already in a state of depletion of hepatic glycogen, demonstrated marked hyperglycemia 24 h after endotoxin administration in small doses of less than 2 mg/kg.     

Hypersensitivity to endotoxin hepatotoxicity in rats with inflammatory lesions

The ratio of sinusoidal nonparenchymal cells to hepatocytes in rat liver was significantly increased following induction of inflammation, and decreased after subsequent exposure to endotoxin, particularly in the region around the terminal portal venules. Rats with inflammatory lesions were more sensitive to endotoxin hepatocytotoxicity than normal controls, as judged from the dose-dependent increase in activity of serum transaminases and from the extent of liver tissue injury. In addition, these animals, which were already in a state of depletion of hepatic glycogen, demonstrated marked hyperglycemia 24 h after endotoxin administration in small doses of less than 2 mg/kg.     

Antagonismus zwischen Heparin und 5-Hydroxytryptamin (Serotonin)in vitro

Summary In the isolated rat colon and uterus, heparin caused inhibition or elimination of contractions occurring after the administration of 5-hydroxytryptamine. In contrast to this, neither Tyrode's solution, nor glycogen, nor dextran produced any change in the response of these organs to 5-hydroxytryptamine.     

Changes in serum proteins and in major liver constituents following carbon tetrachloride and a high-fat choline-free diet in rats

Summary Both carbon tetrachloride and a high-fat, low-protein choline-free diet cause hepatomegaly in rats due to an accumulation of both lipids and proteins with a concomitant increase in deoxyribonucleic acid content. CCl₄ causes a decline in hepatic glycogen. Serum albumin level is decreased in CCl₄-treated rats and increased in those fed the experimental diet.     

Effect of crustacean eyestalk extracts on carbohydrate levels in the South Indian scorpionHeterometrus fulvipes (Koch)

Summary Injection of eyestalk extracts of freshwater crab and marine prawn caused elevation of haemolymph sugar level, and decrease in free sugar and glycogen levels, in the hepatopancreas of the scorpion.     

Étude biochimique des poissons: 2. Variations semestrielles de la teneur en glycogène,en lipides totaux et en minéraux du tissu musculaire de la truite Arc-en-ciel (Salmo gairdnerii Rich)

Summary The variations of glycogen, lipids and ashes in muscular tissue of the Rainbow trout (Salmo gairdnerii Rich.) show that during sexual cycle there are 4 periods. Each period corresponds to a particular biological activity. The sexual activity cannot explain all the modifications of glycogen content.     

Temperature-dependence of stress-induced hepatic autophagy

Summary In rats, restraint for 48 h elicits hepatic glycogen depletion, autophagy and other ultrastructural changes (e.g. mitochondrial enlargement and rough endoplasmic reticulum disorganization) associated with marked hypothermia. By restoring the body temperature of these animals, all the hepatocytic alterations are abolished.Supported in part by the Medical Research Council of Canada (Block Term Grant MT-1829) and the Conseil de la recherche en santé du Québec. A preliminary report of this work was presented at the 19th Annual Meeting of the Canadian Federation of Biological Societies, Halifax, 15–18 June 1976.Recipient of a studentship from the Conseil de la recherche en santé du Québec.The authors thank Mr M. Audet, Mrs A. Perea and Miss F. Dionne, for their excellent technical assistance.     

Seasonal variations in liver metabolism of the green frogRana esculenta (L.)

Summary Rana esculenta (L.) kept under natural conditions show almost constant b.wt in the annual cycle. Liver weight, however, has a distinct peak in October/November which is also evident in the liver index. The liver storage materials: glycogen, triglyceride and protein, show 2 distinct maxima (spring, autumn).     

The effect of epinephrine and the hyperglycemic factor of the scorpion's cephalothoracic ganglionic mass (CTGM) on the phosphorylase activity of hepatopancreas of the scorpion,Heterometrus fulvipes C. Koch

Summary Injection of epinephrine and CTGM extract showed different effects on hepatopancreatic phosphorylase activity and levels of total carbohydrate and glycogen in heterometrus fulvipes. The former hyperglycemic principle involves phosphorolysis of glycogen whereas the latter does not.The authors are grateful to Proff. K. S. Swami and S. Nagaiah. An award of Junior Research Fellowship by the Council of Scientific and Industrial Research, New Delhi is acknowledged by K. R.     

Morphological evidence for axonal transport of glycogen in neurons innervating cutaneous receptors inLacerta sicula (Squamata: Reptilia)

Summary Three types of glycogen-containing cutaneous nerve terminals — two of them hitherto unknown — are described. It is shown that the glycogen is synthesized in the perikaryon and transferred to the terminals by means of slow axoplasmic transport.