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.

     

Anaerobic metabolism in the lugworm Arenicola marina during low tide: The influence of developing reproductive cells

• 1.1. The extent of anaerobic energy production of Arenicola marina during low tide is dependent on the season and on the locality in the intertidal.
• 2.2. Anaerobic energy production was only found: (a) in animals from sediments, which fall dry for several hours; (b) in summer and autumn, but not in winter and spring.
• 3.3. A correlation between the extent of anaerobic energy production and the development of gametes was demonstrated.
• 4.4. The process of spawning represents a great stress to the animals. At this time the ability of Arenicola marina to survive anaerobic conditions was reduced drastically.

     

The influence of seasonal changes on energy metabolism in Mytilus edulise (L.).—III. Anaerobic energy metabolism

• 1.1. Seasonal changes in the accumulation of end products after 48 hr of exposure to air and in the composition of the free amino acid pool were studied in Mytilus edulis.
• 2.2. The accumulation levels of succinate and acetate showed only weak seasonal changes.
• 3.3. Conversion of succinate to propionate was high in summer and virtually zero in winter
• 4.4. Alanine and most other free amino acids were present in relatively high concentrations in summer and early autumn and reached minimal values in winter and early spring.
• 5.5. Exceptions were glutamate, aspartate and taurine, which showed hardly an season related changes and glycine, which changed inversely to the majority of the free amino acids.
• 6.6. The anaerobic formation of alanine was inversely proportional to the endogenous concentration.
• 7.7. The only other free amino acids affected by anaerobiosis were glutamate and aspartate, which respectively increased and decreased under these conditions.

     

In vivo levels of aminoacyl-tRNA species during acclimatization of the carp Cyprinus carpio

• 1.1. The behaviour of the tRNA population during the acclimatization process was studied, examining the intracellular levels of aminoacylated-tRNAs in livers from summer and winter adapted carps (Cyprinus carpio).
• 2.2. The in vivo content of Val-tRNA, Ala-tRNA and Met-tRNA decreased significantly during the summer season, in which Val was 80%, Ala 47% and Met 54% with respect to the values attained in winter.
• 3.3. The half-life for the nonenzymic deacylation showed significant variations for the two populations of aminoacyl-tRNA obtained from summer and winter acclimatized fish.

     

Seasonal variation of phosphatase activity in the hepatopancreas of the snail Helix pomatia L.

• 1.1. Body weight, the weight of the hepatopancreas, protein content in the hepatopancreas and phosphatase activity at pH 8.5 in the hepatopancreas are great in spring and summer, and decrease during autumn and winter.
• 2.2. Phosphatase activity at pH4.5 is the same throughout the year.
• 3.3. Participation of acid phosphatases in extracellular and intracellular digestion and participation of alkaline phosphatases in food resorption and calcium deposition are postulated.

     

The effects of acclimatization on body weight and oxygen consumption in Dipodomys panamintinus

• 1.1. Seasonal acclimatization effects on oxygen consumption, body temperature, and body weight were evaluated in three different experimental groups of Dipodomys panamintinus.
• 2.2. Body weights of wild field as well as captive animals housed in outdoor sand cages were maximum in winter and lowest in summer for both sexes.
• 3.3. Mean oxygen consumption was maximum in winter and lowest during spring in both sexes of the wild field and captive exposed groups.
• 4.4. Neither weight nor oxygen consumption of indoor control animals varied with the seasons.
• 5.5. No significant differences in body temperatures were observed during either the fall or winter seasons.

     

Dehydration does not influence the summer versus winter thermal adaptation changes in rabbits (oryctolagus cuniculus), living in natural photoperiod

• 1.1.|Resting metabolic rate of laboratory rabbits kept indoors is susceptible to seasonal fluctuations and is higher in winter than in summer.
• 2.2.|Thermoneutral zone of rabbits under these conditions may shift downwards in winter and upwards in summer.
• 3.3.|Both of these adjustments in thermoregulation seem to be related to the seasonally changing photoperiod.
• 4.4.|Dehydration does not influence these thermoregulatory adaptive changes.

     

Carbohydrate metabolism during osmoregulation in Chasmagnathus granulata dana, 1851 (crustacea,decapoda)

• 1.1. Since glucose is one of the main energetic substrates for general metabolic processes in crustaceans, analysis of carbohydrate levels can furnish information on the energy metabolism of intact animals during osmoregulation.
• 2.2. Different groups of Chasmagnathus granulata were transferred to different salinities (0 and 40%), and the glucose and glycogen concentrations in blood, gills, muscle and hepatopancreas were determined at the beginning of the experiment and 24, 72, 168 and 360 hr after the salinity changes.
• 3.3. Differences in tissues carbohydrate levels were observed between summer and winter, that reflected differences in reserve mobilization.
• 4.4. In the summer, hypo- and hyperosmotic shocks induced an increase in carbohydrate levels in almost all tissues studied, indicating gluconeogenesis.
• 5.5. In the winter, a carbohydrate mobilization occurred only in the gills and hepatopancreas after both osmotic shocks.
• 6.6. Thus, the substrate reserve used for energy production required for osmoregulation seems to be dependent on the season and tissues.

     

Oxygen consumption in the tortoise,Testudo hermanni G., subjected to sudden temperature changes in summer and autumn

• 1.1. A respirometer for long-term measurements of oxygen consumption in terrestrial vertebrates is described.
• 2.2. The tortoise, Testudo hermanni Gmelin, investigated in summer and autumn, presents a day-night rhythm of oxygen consumption at 28 and 18°C but not at 8°C.
• 3.3. The standard metabolic rate presents an important and constant thermal dependence in the range 8-18-28°C.

     

Seasonal changes of total lipids in the turtle Sternotherus odoratus

• 1.1. Seasonal variation in total lipids was examined in several body components of the turtle Sternotherus odoratus.
• 2.2. Carcass fat stores in both sexes were depleted during winter. Additionally, a decline in carcass lipids was associated with increases in gonadal mass.
• 3.3. Concentrations of liver lipids were maximal during August and minimal during winter.
• 4.4. Males showed little seasonal change in plasma lipid levels, whereas females had seasonal peaks temporally associated with ovarian development and carcass fat storage.
• 5.5. Ovarian concentrations of lipids were minimal after nesting and increased during fall.
• 6.6. Results suggest that S. odoratus uses stored fats both for reproduction and maintenance during winter.

     

Kinetic studies of vitellogenin metabolism in the elasmobranch Scyliorhinus canicula L.

• 1.1. The appearance of vitellogenin in the plasma of adult female Scyliorhinus canicula and its subsequent disappearance and conversion into yolk granules were monitored by an isotopic method. Rates of vitellogenin synthesis in different fish were compared.
• 2.2. There was considerable individual variation in the rate of synthesis and in the plasma half-life of vitellogenin; measured values of the latter ranged from 132 to 303 hr (mean 216 hr) at 7 ± 2°C.
• 3.3. Winter temperature stimulated vitellogenin synthesis in midsummer, but winter photoperiod did not do so.
• 4.4. Captivity without food for 22 days reduced the rate of vitellogenin synthesis in summer but had no effect in winter.

     

Seasonal changes of circulating blood parameters in the grass snake Natrix natrix natrix L.

• 1.1. Seasonal changes of circulating blood parameters of Natrix n. natrix were evident and involved both sexes to the same extent.
• 2.2. A significant decrease in red cell count, haematocrit and haemaglobin concentration in the mating period, and an increase in those parameters and mean cell volume in autumn were observed, and haemodilution during winter torpor.
• 3.3. The changes during the breeding season had probably a hormonal background; in winter, they resulted first of all from a decreased erythropoietic activity and, to a lesser extent, from an increased red blood cell breakdown rate. However, the possibility that some erythrocytes were withdrawn from the circulation cannot be excluded.
• 4.4. Winter lymphocytopenia, eosinocytopenia and neutrophilic granulocytosis in females during egg laying were expressions of changes of leucocyte formula.
• 5.5. Seasonal cyclicity was found only with respect to the white cell count in males and the eosinophile fraction in males and females.
• 6.6. Probable reasons for, and mechanisms of the changes in blood composition are discussed.

     

Changes in organic storage compounds during the active and inactive periods in a desert snail,Sphincterochila prophetarum

• 1.1. S. prophetarum uses during the aestivation periods of summer and winter only 33% and 22%, respectively, of the total organic storage content, even though the summer aestivation period is much longer.
• 2.2. During the long summer aestivation period the snails use a small amount, 0.2% per day, of the different organic storage materials.

     

Seasonal variation in the metabolic rates and Q10-values of the fingernail clam,Sphaerium striatinum lamarck

• 1.1. Metabolic rates were highest during periods of maximum reproduction.
• 2.2. The exponent of the metabolic rate-weight equation varied seasonally, rates of metabolism of small animals exhibited greater annual fluctuations than those of large animals.
• 3.3. Absolute and weight-specific Q₁₀s (determined at 5–10°C above field temperatures) for smaller clams were greatest in the winter; absolute values of Q₁₀ were highest for larger individuals in the summer.
• 4.4. Small clams had Q₁₀ < 1.0 in the summer; Q₁₀-values for larger clams were near 1.0 at this time.
• 5.5. 38.9% of the total energy assimilated by the population annually was allocated to metabolism, which is near the low end of the range of values reported for freshwater molluscs, suggesting that this species can partition a large amount of energy to growth and reproduction.

     

Seasonal changes in condition and lipids composition of the bivalve Macoma balthica L. from the gulf of Gdańsk (Southern Baltic)

• 1.1. The total lipids content and composition of lipid classes, their per cent in dry wt of soft tissues and level in standard animal, as well as composition of fatty acids and sterols were studied in Macoma balthica collected from three sites in the Gulf of Gdańsk, in the years, 1983–1984.
• 2.2. The increase in the content of total lipids, triacylglycerols, oleopalmitic, 16:1 and eicosapentaenoic acids, 20:5, C27 sterols (mainly cholest-5en-3β-ol), in spring and early summer and their decrease in autumn and winter were observed.
• 3.3. Content of phospholipids, sterols and hydrocarbons in the tissue dry wt of Macoma balthica remained nearly constant.

     

Adaptive strategies of selective fatty acid deposition in the bone marrow of desert bighorn sheep

• 1.1. The winter distribution of fatty acids in the fore and hind limb of the desert bighorn, Ovis canadensis cremnobates, increased in unsaturation distally over the length of the leg; the greatest change occurred at the level of the radius and tibia.
• 2.2. Summer fatty acid marrow composition decreased significantly in unsaturation distally when compared to winter values. The greatest changes occurred at the metacarpus (metatarsus)-phalanges.
• 3.3. The summer distribution of distally accumulated saturated fatty acids could be an adaptation to maintain the limbs as heat dissipators by insulating against conductive heat gain from a hot environment and protecting cell membranes of heterothermic tissues against thermal denaturation.

     

Specific dynamic action (SDA) in the supralittoral isopod,Ligia pallasii: Effect of ration and body size on SDA

• 1.1. Ration and body size effects on specific dynamic action (SDA) were investigated in the supralittoral isopod Ligia pallasii using seaweed and chemical diets.
• 2.2. SDA increased asymptotically with ingested meal size for all diets.
• 3.3. Body weight had a significant positive effect on SDA for only one of the six diets tested, but weak tendencies were present in the data for the other diets.
• 4.4. SDA appeared to increase geometrically with increasing concentration of amino acids at high ration levels.

     

Protein,fatty acids,calcium and phosphate absorption along the gastrointestinal tract of the young turkey

• 1.1. The net absorption of protein, fatty acids, calcium and phosphate along the small intestine of the turkey (Meleagris gallopovo) was evaluated with the aid of ⁹¹Y as a reference substance.
• 2.2. About 85% of the ingested protein was absorbed, with most of the absorption occurring in the duodenum and upper jejunum.
• 3.3. The overall lipid absorption coefficient was around 90%, and was inversely related to the fatty acid chain length and saturation.
• 4.4. Most of the lipid absorption occurred in the duodenum and jejunum.
• 5.5. Calcium absorption also occurred in the duodenum and jejunum: its fractional rate decreased with calcium intake.
• 6.6. Phosphate absorption occurred mostly in the duodenum and jejunum and its efficacy was only slightly affected by dietary phosphate intake.
• 7.7. The high nutrient absorption in the turkey duodenum, relative to that of the chick (Gallus domesticus), was discussed.

     

The fate of the bowman-birk trypsin inhibitor from soybeans in the digestive tract of chicks

• 1.1. Intestinal absorption of the Bowman-Birk trypsin inhibitor from soybeans was studied comparatively in chicks by direct follow-up of absorbed radioactive inhibitor and by radioimmunological estimation of the unlabelled inhibitor.
• 2.2. Initial studies, performed in vitro by the inverted sac technique, suggested that both the native inhibitor and its degradation products were absorbed.
• 3.3. However, the results obtained for in situ and in vivo experiments indicated that the absorption of the native inhibitor is negligible.
• 4.4. Most of the inhibitor is degraded during its passage through the intestine, and the majority of the degradation products is excreted in the feces.
• 5.5. The effects of ingested inhibitor on pancreas enlargement and on secretion of pancreatic enzymes stems from an indirect effect on the intestine.

     

Relative bioavailability and DNA adduct formation of benzo[a]pyrene and metabolites in the diet of the winter flounder

• 1.1. Radiolabeled metabolites of the carcinogenic polycyclic aromatic hydrocarbon benzo[a]pyrene (BaP) were shown to be absorbed through the diet of the winter flounder, Pseudo pleuronectes americanus.
• 2.2. Oral bioavailability of a mixture of naturally produced metabolites was significantly less than that of the parent BaP.
• 3.3. Oral bioavailability of a pure metabolite, BaP-7,8-dihydrodiol (7,8-D) was found to be similar to that of BaP.
• 4.4. Both metabolites and BaP formed DNA adducts in liver.