Three digestive tract endocrine peptides and the circannual cycle of body weight in Spermophilus lateralis

• 1.1. Thirty-one male golden-mantled ground squirrels were divided into four physiological groups: low wt summer, medium wt summer, high wt summer and hibernation period. A second group of 10 females was divided into two groups: hibernation period at low T_b and hibernation period during a periodic arousal.
• 2.2. Blood serum, pancreas and antral stomach region were collected from each animal.
• 3.3. The serum was analysed by radioimmunoassay for pancreatic polypeptide immunoreactivity, the pancreas for pancreatic polypeptide and somatostatin immunoreactivity and the antral region of the stomach for gastrin immunoreactivity.
• 4.4. Significant between-stage differences (P < 0.05) were found in serum pancreatic polypeptide concentration and in pancreatic somatostatin content.

     

Glycogen and galactogen in the albumen gland of the freshwater snail Lymnaea stagnalis: Effects of egg laying,photoperiod and starvation

• 1.1. Glycogen and galactogen contents of the albumen gland of the freshwater snail Lymnaea stagnalis were determined under different conditions, known to influence these polysaccharides viz egg laying, photoperiod and starvation.
• 2.2. After oviposition, the galactogen content is restored within 32 hr, whereas glycogen remains constant during this period. Short-day photoperiods favour accumulation, long-day photoperiods induce depletion of glycogen. In contrast, the galactogen content is not affected by the photoperiod.
• 3.3. Since glycogen and galactogen are present in the same cells of the albumen gland, the independent variation of these polysaccharides would imply the presence of separate intracellular regulation mechanisms.

     

Measurements of oxygen consumption in Mytilus edulis during exposure to,and recovery from,high sublethal concentrations of formaldehyde,benzene and phenol

• 1.1. The rate of oxygen consumption has been monitored continuously in M. edulis during acute exposure to high sublethal concentrations of formaldehyde, phenol and benzene and subsequent recovery periods of 96 hr.
• 2.2. The results are discussed in relation to changes in the electrochemical potential difference of sodium, the content of ATP and the tissue concentration of strombine.
• 3.3. After exposure to benzene and phenol, an increase in the rate of oxygen consumption that could not be explained by oxygen debt from the exposure period was observed.
• 4.4. Depression of the rate of oxygen consumption after exposure to formaldehyde may be explained by a reduced ability to extract oxygen from the water.
• 5.5. The pattern of oxygen consumption and behavioural responses, as well as the combined changes in the biochemical markers, were distinctly different in the three cases.

     

Seasonal variation in the energy metabolism in an estuarine crab,Chasmagnathus granulata (Dana, 1851)

• 1.1. The effects of seasonal variation on the carbohydrate and lipid metabolism of the Chasmagnathus granulata were investigated.
• 2.2. Glycemia is high in winter and summer and low in spring and fall.
• 3.3. The glycogen content in the hepatopancreas and muscle is higher in fall and winter, and decreases during spring and summer.
• 4.4. The muscle lipids are higher in summer, and decrease during fall and winter whereas hepatopancreas lipids are higher except in the fall.
• 5.5. The crabs show change in the metabolic pattern of lipids and carbohydrates during the seasons of the year.

     

The effect of time on physiological changes in eel Anguilla anguilla,induced by lindane

• 1.1. Eel were exposed to a sublethal concentration of lindane (0.335 ppm) for 6, 12, 24, 48, 72 and 96 hr.
• 2.2. Concentrations of glycogen, glucose, lactate, pyruvate and lipids were determined in gill tissue after lindane exposure.
• 3.3. Gill glycogen descreased and glucose levels increased at 6 hr of treatment, lactate and pyruvate concentration increased between 6 and 48 hr. Total lipid values decreased between 6 and 24 hr; thereafter, the levels increased up to 72 hr of exposure.
• 4.4. Clear changes were found in all parameters tested in gill tissues. The observed effects of lindane on metabolism in fish are discussed in relation to acute stress syndrome.

     

Carbohydrate metabolism in several tissues of rainbow trout,Oncorhynchus mykiss,is modified during ovarian recrudescence

• 1.1. Several pathways of carbohydrate metabolism were evaluated in three different tissues—liver, gonad and kidney—of a hatchery-reared population of rainbow trout (Oncorhynchus mykiss) which characterised two different stages of their gonadal maturation, i.e. previtellogenesis and established exogenous vitellogenesis.
• 2.2. A fall in liver glycogen levels was observed during exogenous vitellogenesis. A decrease in activity of the enzymes involved in glycolysis and in the pentose phosphate shunt was also observed, suggesting that at the end of exogenous vitellogenesis the necessity of energy and reducing power has decreased compared to the situation at the onset of this period.
• 3.3. The main changes observed in gonad during vitellogenesis were the decreased activity of glycolysis and the pentose phosphate shunt as well as increased glycogen levels. The stored glycogen should be used later in association with the embryo development.
• 4.4. No major changes were observed in kidney metabolism throughout the vitellogenic process.
• 5.5. Exogenous vitellogenesis in rainbow trout is mainly associated with increased glycogen levels in the gonad and decreased metabolic activity in the liver.

     

Identification of a glycoprotein complex containing a glycogen synthase isozyme in Ascaris Suum obliquely-striated muscle

• 1.1. A glycogen/protein complex which contains the major portion of glycogen synthase activity in Ascaris suum muscle has been purified.
• 2.2. The complex contains two proteins which can be dissociated from a glycoprotein component.
• 3.3. The glycoprotein contains glycogen-like domains and is resistant to trypsin digestion.
• 4.4. The glycogen synthase activity in the purified complex catalyzes glycogen synthesis in the absence of exogenous glycogen, but demonstrates an absolute glucose 6-phosphate requirement for activity.
• 5.5. The data support the hypothesis that this isozyme of glycogen synthase is significantly different from the cyclic AMP-regulated enzyme.

     

A novel inhibitor of glycogen phosphorylase from crayfish hepatopancreas

• 1.1. A novel glycogen phosphorylase inhibitor was partially purified from crayfish hepatopancreas.
• 2.2. The inhibitor was found only in two species of crayfish examined, and not in lobster, fresh and salt water clams, mussels or cockroaches.
• 3.3. The inhibitor is a small protein (M_r = 23,000) which did not show proteolytic activity.
• 4.4. Preliminary kinetic analysis of the inhibitory mechanism indicated that it bound to both glycogen and the glycogen phosphorylase protein.
• 5.5. Inhibitor binding to glycogen resulted in a competitive inhibition pattern with respect to glycogen phosphorylase (inhibition constant of ca 10 μg/ml).
• 6.6. The inhibitor also bound glycogen phosphorylase directly with a binding coefficient of 100 μg/ml resulting in a partially non-competitive inhibition pattern with respect to phosphate.

     

Dna breakage and inactivation resulting from hydroxylamine and/or cis-Diamminedichloroplatinum(Ii) interactions with plasmid dna

• 1.1. Occurrence of lesions induced in plasmid DNA by cis-DDP and by HA was quantified both as a transforming activity and as conformation integrity of supercoilcd pBR322 DNA. Fifty per cent decrease of the biological activity of plasmid DNA, not accompanied by measurable change of DNA conformation, was observed after a single exposure of DNA to cis-DDP (1 hr/37°C).
• 2.2. HA induced conversion of supercoiled DNA to other topological forms in a dose-dependent manner.
• 3.3. One- and two-strand DNA breaks were determined electrophoretically with high sensitivity. Cis-DDP exposed DNA relaxed at 30 times lower HA concentration compared to intact DNA.
• 4.4. This effect may be connected with a local distortion of DNA structure at the cis-DDP—DNA bond, which makes possible high effectivity of HA-DNA interaction.
• 5.5. On other hand, biological activity stayed at the 50% level despite breaks induced in DNA.
• 6.6. This finding supports the idea that DNA breaks occur at the locations which were modified during the exposure of DNA to cis-DDP.
• 7.7. The importance of the DNA structure during interaction with HA may be seen during HA-DNA interaction at heat-denaturation of supercoiled DNA. At this condition, the DNA breaks were induced at 100 times lower concentration of HA.
• 8.8. We conclude, on the basis of these results and results published earlier, that local distortion of supercoiled DNA structure, which is caused by the cu-DDP bond, and the local DNA uncoiling caused by heat-denaturation are related to high HA-DNA reactivity.

     

Short-term osmotic responses of cells and tissues of the sea anemone,Condylactis gigantea

• 1.1. Cells of tentacles and body wall of the sea anemone Condylactis gigantea behaved as simple osmometers during 5hr exposure to 50, 67, 83, 100 and 125% sea-water.
• 2.2. All intracellular water appeared to be osmotically active.
• 3.3. Cell sodium, chloride and total osmolyte content remained invariable, with taurine decreasing and potassium increasing as sea-water concentration was reduced.
• 4.4. Tissues, as a whole, exhibited a pseudoregulatory response to changes in salinity as the large and osmotically inert extracellular space buffered volume changes to a considerable extent.

     

Sugar accumulation in hibernating adult bees: An example of the unique energy reservoir for hibernation

• 1.1. Sugars, sugar-alcohols, glycogen, triacylglycerol contents in hibernating adult bees are compared in relation to the hibernating habits of the bees. Monosaccharide content is low in Andrena and Osmia which hibernate in natal blood cells, which very high in Lasioglossum spp. which feed before hibernation.
• 2.2. Distribution of sugars within the body of hibernating Lasioglossum reveals that trehalose is the major sugar accumulated in hemolymph, and that the crop contains a large amount of monosaccharides.
• 3.3. Seasonal changes of sugars and glycogen contents in L. duplex strongly suggest that trehalose accumulated is derived, not from the glycogen in the fat body, but from monosaccharides in the crop.

     

Glycogen synthetase in the sea mussel Mytilus edulis L.—II. Seasonal changes in glycogen content and glycogen synthetase activity in the mantle tissue

• 1.1. The glycogen content of the mantle tissue reached a maximum in the summer (May–July) with levels of 41.0–53.5% of the dry tissue weight.
• 2.2. Seasonal changes in glycogen synthetase activity showed that the I-activity (independent of G6P) increased up to 10-fold in June as compared with December. The measured I-activity of glycogen synthetase was sufficient to account for the accumulation of mantle glycogen in the summer.
• 3.3. The I-activity of glycogen synthetase declined rapidly in July of each year. A possible role for the inhibition of glycogen synthetase by high levels of tissue glycogen is suggested.
• 4.4. The I-activity in the mantle tissue of mussels on the shore was higher than that for animals starved in the laboratory for 2–3 days. The differences were minimal in early May but increased markedly in late May–July. Starved mussels returned to the shore showed an increase in I-activity of glycogen synthetase.
• 5.5. Injection of 30 μmol glucose into the adductor muscle increased the concentration of glucose in the mantle fluid to 2.0–2.5 mM. A similar injection of 60 μ mol glucose resulted in a time-dependent increase in the I-activity of glycogen synthetase.
• 6.6. Injection of mussels with mammalian insulin or anti-insulin serum had no effect on the activity of glycogen synthetase. Our results are at variance with those of other workers who have used the mammalian hormone in molluscan studies (see Discussion).

     

Effects of starvation and a carbohydrate-rich diet on glycogen metabolism in a gastropod mollusc,Megalobulimus oblongus

• 1.1. Administration of a carbohydrate-rich diet increased haemolymph glucose levels and glycogen concentration in hepatopancreas, mantle and muscle.
• 2.2. Glycogen concentration in tissues decreases after 2 weeks of starvation and haemolymph glucose levels did not change significantly.
• 3.3. However, starvation did not induce a decrease in the intrinsic synthetic capacity in tissues.
• 4.4. Glycogen synthesis in tissues from animals fed with lettuce or a carbohydrate-rich diet, increases with increasing glucose concentration in the media.
• 5.5. However, in mantle slices from snails adapted on a carbohydrate-rich diet, the glycogen synthetic capacity was lower than in slices from snails fed with lettuce.

     

Sublethal effects of hypoxia in the abalone (Haliotis rufescens) as measured by in vivo31P NMR spectroscopy

• 1.1. Effects of hypoxia were investigated in red abalones (Haliotis rufescens) using a flow-through exposure system and in vivo³¹P NMR spectroscopy.
• 2.2. Following seawater acclimation, abalones were exposed to air for 1 hr, then seawater for 2.5 hr to check recovery; parallel controls were performed without air exposure.
• 3.3. In foot muscle, hypoxia produced a decrease in phosphoarginine concentration and intracellular pH, an increase in inorganic monophosphate concentration, and no change in that of ATP; upon resubmergence, all effects generally recovered.
• 4.4. The changes induced by hypoxia during normal tidal changes are consistent with the blockage of mitochondrial oxidative phosphorylation.
• 5.5. Use of in vivo NMR allows measurement of the biochemical effects of natural stress factors in live, intact aquatic organisms in the laboratory.

     

1H NMR study of metabolic alterations in the small intestine of rats infected with Hymenolepis diminuta

• 1.1. 1H NMR spectra of the duodenum, jejunum and ileum tissues of the small intestine of a rat showed metabolic gradients.
• 2.2. The concentrations of metabolites in these gut regions were altered by the presence of the tapeworm Hymenolepis diminuta.
• 3.3. In the infected duodenum there was significantly less glycogen, glucose and phosphocreatine/creatine, but significantly more lactate than in the corresponding controls.
• 4.4. Infected jejunum contained significantly less betaine but significantly more succinate, alanine and lactate.
• 5.5. Infected ileum had significantly less glycogen and taurine but significantly more alanine and lactate.

     

Effect of exposure to atmospheric air on blood glucose and lactate concentrations in two crustacean species: A role of the Crustacean hyperglycemic hormone (CHH)

• 1.1. In intact (control) crabs (Carcinus maenas) and crayfish (Orconectes limosus) a significant (P < 0.01) increase in both glucose and lactate concentrations in the blood was observed after exposure to air. Such changes were not observed in either eyestalk-less or eyestalk-less and saline injected animals (P > 0.05).
• 2.2. Injections of Crustacean hyperglycemie hormone (CHH) into eyestalk-less animals before exposure to air were able to reverse the effects of eyestalk ablation, i.e., significant increases (P < 0.01) in blood glucose and lactate could again be observed.
• 3.3. Significant hyperglycemia (P < 0.01), but no changes in lactate concentration (P > 0.05), was observed after injection of CHH in eyestalk-less submerged animals.
• 4.4. These results suggest that the increase in glycolysis after air exposure is facilitated by CHH, possibly by increased substrate availability due to glycogen degradation.

     

Effect of ozone exposure on the compositions of gill and erythrocyte membrane lipids and proteins of Japanese charr (Salvelinus leucomaenis)

• 1.1. Compositions of lipids and proteins of erythrocytes (RBC) and gills from Japanese charr (Salvelinus leucomaenis) which were exposed to 0.4 and 0.7 ppm ozone for 30 min were compared with those of the control.
• 2.2. On exposure to ozone, both RBC and gill membrane phospholipid content, especially phosphatidylethanolamine (PE), dropped.
• 3.3. The decrease of PE was brought about by the decrease of docosahexaenoic acid content which comprised the major component of PE.
• 4.4. RBC membrane protein with 215 and 225 kDa, which is equivalent to cytoskeletal protein, selectively disappeared on exposure to ozone.

     

Lipid and carbohydrate metabolism of the intertidal crab Chasmagnathus granulata dana, 1851 (Crustacea: Decapoda) during emersion

• 1.1. Lipid, glucose and glycogen concentrations were measured in different tissues of the crab Chasmagnathus granulata during emersion.
• 2.2. After 6 hr of emersion no reduction in the total amount of carbohydrates was found to occur, suggesting that a general metabolic arrest was taking place.
• 3.3. A transitory increase in haemolymphatic glucose and lipid levels was observed. Possible causes are therefore discussed in relation to changes in the flux of substrates for energy production.
• 4.4. The mobilization of carbohydrates and lipids to the gills, observed only during summer, may be concerned with energy supplying for ionic regulation.

     

Trehalose synthase and trehalase behaviour in yeast cells in anhydrobiosis and hydrobiosis

• 1.I. Trehalose synthase and trehalase behaviour has been analysed in cultured yeast cells isolated from baker's yeast to increase the understanding of the mechanisms involved in trehalose content modifications observed in anyhydrobiois and hydrobiosis.
• 2.2. After desiccating yeast cells to a constant weight, trehalose levels sharply increased, whereas the glycogen content decreased, trehalose synthase was stimulated and trehalase was significantly inhibited.
• 3.3. In desiccated cells after a rehydration for 15 min, trehalose levels dropped, the glycogen content further decreased, the activity of trehalose synthase declined while that of trehalase was dramatically stimulated.
• 4.4. After rehydration for 12hr, while the trehalose and glycogen content decreased even more, the behaviour of the two enzymes was completely reversed, trehalose synthase being activated and trehalase inhibited.
• 5.5. The reasons for such impressive enzyme activity alterations in desiccated and rehydrated cells for the moment remain unknown.

     

The Proteome of Pig Spermatozoa Is Remodeled During Ejaculation

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Highlights

• •Proteome of mature boar spermatozoa from cauda epididymal and ejaculated sources were analyzed by iTRAQ-based LC-MS/MS.
• •1,723 sperm proteins identified (974 of Sus scrofa taxonomy).
• •1,602 sperm proteins quantified (960 of Sus scrofa taxonomy).
• •32 Sus scrofa sperm proteins were differentially expressed among sperm sources.
• •The proteome of boar spermatozoa is remodelled during ejaculation.