148 research outputs found
Glucose and Proline Metabolism in Nautilus
The rates of incorporation of [U-14C]proline and [U-14C]glucose
into CO2 and glycogen were assessed in Nautilus pompilius under both in vitro
and in vivo conditions. Both substrates exhibited tissue-specific rates of metabolism.
However, overall higher rates of incorporation into CO2 and glycogen were
observed with glucose, both with tissue slices and in the intact, catheterized
organism
The Fate of Arginine and Proline Carbon in Squid Tissues
The metabolism of proline and arginine was investigated in
kidney, gill, and heart of the pelagic squid, Symplectoteuthis. The rates of CO2
release from 14C-proline exceeded the rates from 14C-arginine. The metabolic
rate of arginine and proline was assessed by monitoring the incorporation of
arginine-derived carbon into various intermediates. Arginine was metabolized,
through ornithine, to proline as well as to glutamate and various subsequent
derivatives (alanine, octopine, aspartate, and carboxylic acids). The same components
became labeled using 14C-proline as the starting substrate, but only the
gill was capable of converting proline to arginine via the urea cycle. In addition,
14C-proline oxidation rates were high enough to exceed those of 14C-glucose in
at least three tissues, kidney, heart, and inner mantle muscle
The BioKET Biodiversity Data Warehouse: Data and Knowledge Integration and Extraction
International audienceBiodiversity datasets are generally stored in different for-mats. This makes it difficult for biologists to combine and integrate them to retrieve useful information for the purpose of, for example, efficiently classify specimens. In this paper, we present BioKET, a data warehouse which is a consolidation of heterogeneous data sources stored in different formats. For the time being, the scopus of BioKET is botanical. We had, among others things, to list all the existing botanical ontologies and re-late terms in BioKET with terms in these ontologies. We demonstrate the usefulness of such a resource by applying FIST, a combined biclus-tering and conceptual association rule extraction method on a dataset extracted from BioKET to analyze the risk status of plants endemic to Laos. Besides, BioKET may be interfaced with other resources, like GeoCAT, to provide a powerful analysis tool for biodiversity data
Effects of dietary protein and fat level and rapeseed oil on growth and tissue fatty acid composition and metabolism in Atlantic salmon (Salmo salar L.) reared at low water temperatures
A 12 week feeding trial was conducted to elucidate the interactive effects of dietary fat and protein contents and oil source on growth, fatty acid composition, protein retention efficiency (PRE) and β-oxidation activity of muscle and liver in Atlantic salmon (Salmo salar L.) at low water temperatures (4.2 oC). Triplicate groups of Atlantic salmon (initial weight 1168 g) were fed six isoenergetic diets formulated to provide either 390 g kg-1 protein and 320 g kg-1 fat (high protein (HP) diets) or 340 g kg-1 protein and 360 g kg-1 fat (low protein (LP) diets); within each dietary protein/fat level crude RO comprised 0, 30 or 60% (R0, R30, R60, respectively) of the added oil. After 12 weeks the overall growth and FCR were very good for all treatments (TGC; 4.76 (±0.23), FCR; 0.85 (±0.02)). Significant effects were shown due to oil source on SGR and TGC only. The liver and muscle FA compositions were highly affected by the graded inclusion of RO. The PRE was significantly affected by the dietary protein level, while no significant effects were shown in total β-oxidation capacity of liver and muscle. The results of this study suggest that more sustainable, lower protein diets with moderate RO inclusion can be used in Atlantic salmon culture at low water temperatures with no negative effects on growth and feed conversion, no major detrimental effects on lipid and fatty acid metabolism and a positive effect on protein sparing
Aerobic and anaerobic energy expenditure during rest and activity in montane Bufo b. boreas and Rana pipiens
The relations of standard and active aerobic and anaerobic metabolism and heart rate to body temperature ( T b ) were measured in montane groups of Bufo b. boreas and Rana pipiens maintained under field conditions. These amphibians experience daily variation of T b over 30°C and 23°C, respectively (Carey, 1978). Standard and active aerobic and anaerobic metabolism, heart rate, aerobic and anaerobic scope are markedly temperature-dependent with no broad plateaus of thermal independence. Heart rate increments provide little augmentation of oxygen transport during activity; increased extraction of oxygen from the blood probably contributes importantly to oxygen supply during activity. Development of extensive aerobic capacities in Bufo may be related to aggressive behavior of males during breeding. Standard metabolic rates of both species are more thermally dependent than comparable values for lowland relatives. Thermal sensitivity of physiological functions may have distinct advantages over thermally compensated rates in the short growing season and daily thermal fluctuations of the montane environment.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47726/1/442_2004_Article_BF00348070.pd
Arginine, Glutamate, and Proline as Substrates for Oxidation and for Glycogenesis in Cephalopod Tissues
In addition to the usual metabolic roles for arginine and proline in
cephalopod metabolism (the first serving in anaerobic metabolism and the
second in augmenting the Krebs cycle pool of intermediates), we found that
arginine and proline were vigorously oxidized and that their catabolism appeared
to proceed through two common intermediates, glutamate and ornithine.
In addition, we found that glutamate and proline were both capable of supplying
precursors for the gluconeogenic pathway. On a unit mass basis, highest rates of
14C-glutamate and 14C-proline incorporation into glycogen occurred in the
kidney, but when overall organ and tissue mass were considered, muscle, kidney,
and gill displayed comparable rates of glycogen formation from these amino
acids. The possibility was considered that these interactions between arginine,
proline, and glycogen metabolism may be utilized during replenishment of all
three substrate stores during recovery from exhaustive exercise
Two research paths for probing the roles of oxygen in metabolic regulation
Tissues such as skeletal and cardiac muscles must sustain very large-scale changes in ATP turnover rate during equally large changes in work. In many skeletal muscles these changes can exceed 100-fold. Examination of a number of cell and whole-organism level systems identifies ATP concentration as a key parameter of the interior milieu that is nearly universally 'homeostatic'; it is common to observe no change in ATP concentration even while change in its turnover rate can increase or decrease by two orders of magnitude or more. A large number of other intermediates of cellular metabolism are also regulated within narrow concentration ranges, but none seemingly as precisely as is [ATP]. In fact, the only other metabolite in aerobic energy metabolism that is seemingly as 'homeostatic' is oxygen - at least in working muscles where myoglobin serves to buffer oxygen concentrations at stable and constant values at work rates up to the aerobic maximum. In contrast to intracellular oxygen concentration, a 1:1 relationship between oxygen delivery and metabolic rate is observed over biologically realistic and large-magnitude changes in work. The central regulatory question is how the oxygen delivery signal is transmitted to the intracellular metabolic machinery. Traditional explanations assume diffusion as the dominant mechanism, while proponents of an ultrastructurally dominated view of the cell assume an intracellular perfusion system to account for the data which have been most perplexing to metabolic biochemistry so far: the striking lack of correlation between changes in pathway reaction rates and changes in concentrations of pathway substrates, including oxygen and pathway intermediates
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