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PubMed1978

Spectroscopic studies of specifically deuterium labeled membrane systems. Nuclear magnetic resonance investigation of the effects of cholesterol in model systems.

Deuterium nuclear magnetic resonance spectra of dimyristoylphosphatidylcholines specifically labeled in positions 2', 3', 4', 6', 8', 10', 12', and 14', of the 2 chain, of an N-deuteriomethylphosphatidylcholine, and of cholesterol-3alpha-d1, have been obtained by the Fourier transform method at 5.46 and 3.52 T on two "home-built" widebore superconducting magnet spectrometers, as a function of temperature and composition. Data on the specifically deuterium-labeled cholesterol molecule (in nonsonicated membrane systems) permits an estimate of the most probable angle of tilt of the sterol in the membrane, and evaluation of the order parameter (Salpha) describing rigid body motions in the bilayer. Segmental order parameters derived from the data presented allow calculation of individual chain segment projections onto the director axis and, consequently, estimation of effective chain length. It is shown that mathematical models which include chain tilt as well as those which neglect this type of rigid body motion give essentially identical results when applied to the dimyristoylphosphatidylcholine and dimyristoylphosphatidylcholine-cholesterol bilayer systems (in excess water, between 23 and 60 degrees C). Results of calculations of chain length and membrane thickness of a dimyristoylphosphatidylcholine-30 mol % cholesterol membrane system at 23 degrees C give excellent agreement when compared with recent high-resolution neutron diffraction data obtained on specifically deuterium labeled lecithin-cholesterol systems. No evidence for formation of lecithin-cholesterol complexes having lifetimes of approximately 30 ms has been found. Below the pure-lipid gel-liquid crystal phase transition temperature Tc but in the presence of cholesterol, we have obtained further evidence for 1-chain/2-chain nonequivalence. At 10 degrees C, the 2' segment of the 2 chain, but not the 2' segment of the 1 chain or the 3', 6', or 12' segments of the 2 chain, is broadened almost beyond detection. These results are in agreement with similar effects reported recently for the dipalmitoylphosphatidylcholine-cholesterol system and may indicate a bent configuration for the 2 chain, in the lecithin-cholesterol system. Further cooling below Tc results in loss of the 1-chain 2'-position signal intensity plus 2-chain 3', 6', and 12' signals simultaneously. The increase in length of the 2 chain of dimyristoylphosphatidylcholine upon addition of 30 mol % cholesterol of 23 degrees C is about 2.3 A. Addition of cholesterol to a choline-labeled lecithin results in complex behavior of the head group deuterium quadrupole splitting as a function of temperature, and cholesterol mole fraction. Above approximately 20 mol % cholesterol, the main effect is a decrease in quadrupole splitting as cholesterol content increases, the opposite effect to that observed with hydrocarbon chains.

Cholesterol↗
PubMed2001

Methods of mortality (incidence) rates interpretation assessment in small populations.

Findings and procedures include in this article have been realized at Regional Public Health Office in Hradec Králové (Czech Republic) within the period from August 1999 to February 2000. The model sample used in this article dealed only with events of neoplasms incidence in men's population in the region of Eastern Bohemia within the period from 1986 to 1997. The original experimental part concerned to the use of procedures for demographical data standardization for target group of "small populations" including of their selection and spatial distribution. As the result of it, there are topical maps of spatial distribution of incidence (event. mortality) of selected diagnoses according to sex with target area units delimitated by methods of regional geography with around 120 km2 and total average number about 10000 inhabitants. Thanks to using of cluster analysis these maps include inside aggregated information about standardized ratio value, expression of its reliability rate. The original system has been tested thanks to software application and methodical procedures developed by author of this article in the connection with progressive information technology of geographical information system GIS SPANS which all allow quite easily to carry out the detection of another diagnoses spatial distribution within selected resolution and provided data. Mentioned above conclusions may be suggested as a basic descriptive method for the health risk assessment. Another analytical procedures can follow this original method in next phases. The method has brought essentially new view of the disease spatial distribution which has not been used in the Czech Republic in such a range and detail yet. There are being uncovered great possibilities that could in the end contribute to discovering of causal connections - mainly diseases with unfavourable development in time series. At the same time the introductory premise about spatial distribution of events to "skip" with the change of resolution has been confirmed.

Adolescent↗
PubMed1995

Quantitative analysis of trabecular microstructure by 400 MHz nuclear magnetic resonance imaging.

A new approach for the quantitative analysis of trabecular microstructure, based on high-field proton nuclear magnetic resonance (NMR) imaging, is presented. NMR is ideal because it provides high contrast between the marrow proton signal and the bone, which appears with background intensity. Images from 1 cm3 defatted specimens of trabecular bone, suspended in water doped with 1 mM Gd(DTPA) to shorten T1 to about 300 ms, can be obtained at a resolution on the order of 30-50 microns and slice thickness of 150 microns, in 10 minutes at 400 MHz proton frequency. Digital image processing algorithms were designed and evaluated for the measurement of bone area fraction, perimeter length, mean trabecular thickness, and separation. Bone area fraction derived from the NMR images was found to be in excellent agreement with bone volume fraction measured independently (slope = 0.96, r2 = 0.924, p < 0.0001). Errors in the mean trabecular thickness and separation were < 6%. The effects of finite imaging slice thickness and signal-to-noise ratio (SNR) were also evaluated. The data suggest a resolution of 50 x 50 x 200 microns 3 and an SNR on the order of 10 to provide safe margins for precise and accurate structural analysis by means of the algorithms presented in this paper. The method allows simultaneous measurement at multiple locations within the specimen volume without the need for physical sectioning.

Algorithms↗
PubMed2006

No evidence for thick deposits of ice at the lunar south pole.

Shackleton crater at the Moon's south pole has been suggested as a possible site of concentrated deposits of water ice, on the basis of modelling of bi-static radar polarization properties and interpretations of earlier Earth-based radar images. This suggestion, and parallel assumptions about other topographic cold traps, is a significant element in planning for future lunar landings. Hydrogen enhancements have been identified in the polar regions, but these data do not identify the host species or its local distribution. The earlier Earth-based radar data lack the resolution and coverage for detailed studies of the relationship between radar scattering properties, cold traps in permanently shadowed areas, and local terrain features such as the walls and ejecta of small craters. Here we present new 20-m resolution, 13-cm-wavelength radar images that show no evidence for concentrated deposits of water ice in Shackleton crater or elsewhere at the south pole. The polarization properties normally associated with reflections from icy surfaces in the Solar System were found at all the observed latitudes and are strongly correlated with the rock-strewn walls and ejecta of young craters, including the inner wall of Shackleton. There is no correlation between the polarization properties and the degree of solar illumination. If the hydrogen enhancement observed by the Lunar Prospector orbiter indicates the presence of water ice, then our data are consistent with the ice being present only as disseminated grains in the lunar regolith.

Journal Article↗
PubMed2002

Major carotid plaque surface irregularities correlate with neurologic symptoms.

PURPOSE: Many studies have linked carotid plaque surface irregularities with stroke risk, but this relationship has been obscured by the limited ability of available imaging modalities to resolve plaque surface morphology. To address this issue, we performed a prospective study correlating the presenting neurologic symptoms of patients with high-resolution magnetic resonance imaging (MRI; 200 microm) studies of ipsilateral plaque surface invaginations and ledges, lumen shape, and the location of the plaque bulk creating the stenosis. METHODS: One hundred patients, 17 women and 83 men, 45 to 81 years old (mean, 68 years) underwent surgery. Forty-five patients had a transient ischemic attack (TIA) or stroke as the indication for surgery, and 55 patients had no symptoms. Angiograms were obtained in 50 patients. Carotid plaques were removed "en bloc" and placed in gadolinium doped saline for imaging in a Siemens Symphony, 1.5T scanner with a custom-built transmit-receive radiofrequency coil. The resulting slice thickness was 200 microm, with 200 microm by 200 microm in plane resolution. The MRI data and angiograms were reviewed by using National Institutes of Health Image software and read by consensus. A surface irregularity was categorized as a ledge or ulcer and measured by using electronic calipers. Luminal shape was determined at the point of maximal stenosis with a "slice" set at 90 degrees to the lumen axis. The location of the maximal stenosis was recorded. In the internal carotid artery, plaque bulk was designated to be on the flow divider wall or non-flow divider wall. RESULTS: The mean maximal stenosis was 81.5% +/- 12.0%. Surface contour irregularities were found in 80 plaques. Thirty-five plaques were graded as having major surface contour irregularities, and 45 plaques were graded as having minor irregularities. There was a significant correlation between major surface irregularity and TIA or stroke (P <.01). Irregular plaques were identified with angiography, but the irregularity in size was underestimated (P <.01). Only 28% of plaques had circular lumens; 50% had elliptical lumens, and 22% had either crescentic or multi-lobular lumens. The maximal stenosis was located in the internal carotid artery in 82 plaques, the bifurcation in 17 plaques, and the common carotid artery in one plaque. CONCLUSION: Surface irregularities were revealed by means of submillimeter resolution of the carotid plaques with MRI to be common, but only the presence of major irregularities correlated with the patient having TIA or stroke. Lumen shape and plaque location did not appear to predict stroke risk, but may effect imaging accuracy in determining the degree of stenosis. These data further define the relationship of plaque irregularity and cerebrovascular symptoms caused by atheroemboli.

Aged↗
PubMed1985

Diagnosis, treatment and postoperative results of Cushing's disease.

One hundred patients with Cushing's disease were operated on in Nagoya University Hospital between January 1977 and January 1984. Pituitary adenomas were found and resected in 93 cases and complete clinical remissions were observed in 89 treated by operation alone and in two additional cases by operation followed with radiotherapy. The clinical features, pre-operative endocrine data, radiological findings including high resolution CT with coronal and sagittal reconstructions, data of selective venous sampling, operative findings, tumour pathology, postoperative clinical course, postoperative endocrine results and follow-up findings are presented and discussed.

Adenoma, Basophil↗
PubMed2005

Purification, characterisation and crystallisation of photosystem II from Thermosynechococcus elongatus cultivated in a new type of photobioreactor.

The thermophilic cyanobacterium Thermosynechococcus elongatus was cultivated under controlled growth conditions using a new type of photobioreactor, allowing us to optimise growth conditions and the biomass yield. A fast large-scale purification method for monomeric and dimeric photosystem II (PSII) solubilized from thylakoid membranes of this cyanobacterium was developed using fast protein liquid chromatography (FPLC). The obtained PSII core complexes (PSIIcc) were analysed for their pigment stoichiometry, photochemical and oxygen evolution activities, as well as lipid and detergent composition. Thirty-six chlorophyll a (Chla), 2 pheophytin a (Pheoa), 9+/- 1 beta-carotene (Car), 2.9+/-0.8 plastoquinone 9 (PQ9) and 3.8+/-0.5 Mn were found per active centre. For the monomeric and dimeric PSIIcc, 18 and 20 lipid as well as 145 and 220 detergent molecules were found in the detergent shell, respectively. The monomeric and dimeric complexes showed high oxygen evolution activity with 1/4 O(2) released per 37-38 Chla and flash in the best cases. Crystals were obtained from dimeric PSIIcc by a micro-batch method. They diffract synchrotron X-rays to a maximum resolution of 2.9-A, resulting in complete data sets of 3.2 A resolution.

Biomass↗
PubMed1989

The coenzyme analogue adenosine 5-diphosphoribose displaces FAD in the active site of p-hydroxybenzoate hydroxylase. An x-ray crystallographic investigation.

p-Hydroxybenzoate hydroxylase (PHBH) is an NADPH-dependent enzyme. To locate the NADPH binding site, the enzyme was crystallized under anaerobic conditions in the presence of the substrate p-hydroxybenzoate, the coenzyme analogue adenosine 5-diphosphoribose (ADPR), and sodium dithionite. This yielded colorless crystals that were suitable for X-ray analysis. Diffraction data were collected up to 2.7-A resolution. A difference Fourier between data from these colorless crystals and data from yellow crystals of the enzyme-substrate complex showed that in the colorless crystals the flavin ring was absent. The adenosine 5'-diphosphate moiety, which is the common part between FAD and ADPR, was still present. After restrained least-squares refinement of the enzyme-substrate complex with the riboflavin omitted from the model, additional electron density appeared near the pyrophosphate, which indicated the presence of an ADPR molecule in the FAD binding site of PHBH. The complete ADPR molecule was fitted to the electron density, and subsequent least-squares refinement resulted in a final R factor of 16.8%. Replacement of bound FAD by ADPR was confirmed by equilibrium dialysis, where it was shown that ADPR can effectively remove FAD from the enzyme under mild conditions in 0.1 M potassium phosphate buffer, pH 8.0. The empty pocket left by the flavin ring is filled by solvent, leaving the architecture of the active site and the binding of the substrate largely unaffected.

4-Hydroxybenzoate-3-Monooxygenase↗
PubMed2002

A cladistic analysis of the tribe Labiostrongylinea Beveridge, 1983 (Nematoda: Cloacinidae) parasitic in macropodoid marsupials (Marsupialia: Macropodoidea), with a redescription of Parazoniolaimus collaris Johnston & Mawson, 1939.

Morphological characters of both adult and juvenile representatives of the genera comprising the Labiostrongylinea (Strongylida: Cloacinidae: Cloacininae) were examined to prepare an amended description of Paralabiostrongylus bicollaris, a redescription of Parazoniolaimus collaris and a cladistic analysis of the tribe. A cluster of Wallabinema spp., with a fleshy collar on which amphids and deirids are borne, was used as the outgroup for the analysis. The 50% consensus tree, bootstrapped through 1000 replicates, derived from the cladistic analysis had a basal polytomy of Dorcopsinema and Paralabiostrongylus; and a crown polytomy of Labiosimplex, Labiomultiplex, Parazoniolaimus, Labiostrongylus and Potorostrongylus. This analysis provided reasonable evidence for considering all 7 clades as being of generic status and amended diagnoses were prepared. The morphology of the cephalic end of fourth stage juveniles, cephalic papillae and amphids lying posterior to the lips, gave support to the contentions that a fleshy collar is a plesiomorphic character and that Dorcopsinema is the most primitive genus within the group. There was, however, insufficient support from morphological data to provide a robust resolution of generic relationships. Host and biogeographical data were indicative of Paralabiostrongylus and Labiosimplex having been derived from ancestral Dorcopsinema, then Labiostrongylus, Labiomultiplex and Parazoniolaimus derived from ancestral Labiosimplex, and Potorostrongylus from ancestral Labiomultiplex. Additional data, derived from molecular sequencing, is needed to help resolve the relationships within the tribe.

Animals↗
PubMed1981

Orientation of histidine residues in RNase A: neutron diffraction study.

Difference Fourier maps have been calculated at 2.8-A resolution by using neutron diffraction data obtained from a single crystal of RNase A. The phases were derived from a model resulting from the joint refinement of x-ray and neutron data at 2.0-A and 2.8-A resolution, respectively. The orientation of histidine-48 assumed during the refinement of the x-ray model at 2.5 A was confirmed, whereas the other three histidines had to be rotated around C beta--C gamma bonds in order to agree with the neutron difference Fourier maps. In the final model, histidine-12 is clearly hydrogen bonded to the carbonyl oxygen of threonine-45 and to the oxygen of the inorganic phosphate, and histidine-119 is bonded to another oxygen of the phosphate and to the oxygen OD1 of aspartic acid-121.

Crystallization↗
PubMed2004

Crystallization and preliminary X-ray analysis of sulfite dehydrogenase from Starkeya novella.

Crystals of purified heterodimeric sulfite dehydrogenase from Starkeya novella have been grown using vapour diffusion. X-ray diffraction data have been collected from crystals of the native protein at lambda = 1.0 A and close to the iron absorption edge at lambda = 1.737 A. The crystals belong to space group P2(1)2(1)2, with unit-cell parameters a = 97.5, b = 92.5, c = 55.9 A. Native data have been recorded to 1.8 A resolution and Fe-edge data to 2.5 A.

Alphaproteobacteria↗
PubMed1996

Structure Solution of Azurin II from Alcaligenes xylosoxidans using the Laue Method: Possibility of Studying In Situ Redox Changes using X-rays.

We have recently demonstrated that X-rays can be used for changing the redox states of the metal centre in metalloproteins [Murphy et al. (1995). J. Synchrotron Rad. 2, 64-69]. The possibility of using the Laue method for studying the structural changes associated with such X-ray-induced reactions is explored by applying the method to the structure determination of a new azurin (hereafter referred to as azurin II) from the denitrifying bacterium Alcaligenes xylosoxidans. Laue X-ray diffraction data of azurin II were collected at station 9.7 of the SRS Daresbury. Three diffraction patterns were recorded on film packs at three different crystal orientations. The data were processed using the Daresbury Laue Software Suite to give 2224 independent single reflections (R(merge) = 0.136) in the wavelength range 0.36-1.40 A. The data completeness was 44% at 2.55 A resolution. Phase determination for the data was undertaken using the molecular-replacement method; the top peak was chosen in both the rotation function and the subsequent translation function. This solution agreed well with the molecular-replacement solution achieved independently using monochromatic data. The electron-density map showed reasonably good agreement with the model and the copper site was readily recognizable as it had the highest density. To see if the electron-density map could be improved, ;the doublets in the diffraction data were then deconvoluted. This added 26% data in the region infinity-2d(min) resulting in an improvement in the data completeness to 50% and thus in improved continuity of the electron-density map. The quality of these maps is discussed from the point of view of the suitability of this approach for studying redox-induced structural changes.

Journal Article↗
PubMed2004

Preliminary crystallographic analysis of sugar cane phosphoribosylpyrophosphate synthase.

Phosphoribosylpyrophosphate synthases (PRS; EC 2.7.6.1) are enzymes that are of central importance in several metabolic pathways in all cells. The sugar cane PRS enzyme contains 328 amino acids with a molecular weight of 36.6 kDa and represents the first plant PRS to be crystallized, as well as the first phosphate-independent PRS to be studied in molecular detail. Sugar cane PRS was overexpressed in Escherichia coli, purified and crystallized using the hanging-drop vapour-diffusion method. Using X-ray diffraction experiments it was determined that the crystals belong to the orthorhombic system, with space group P2(1)2(1)2 and unit-cell parameters a = 213.2, b = 152.6, c = 149.3 A. The crystals diffract to a maximum resolution of 3.3 A and a complete data set to 3.5 A resolution was collected and analysed.

Escherichia coli↗
PubMed2005

Crystallization and preliminary crystallographic analysis of endo-1,3-beta-glucanase from alkaliphilic Nocardiopsis sp. strain F96.

Endo-1,3-beta-glucanase, an enzyme that hydrolyzes the 1,3-beta-glycosyl linkages of beta-glucan, belongs to the family 16 glycosyl hydrolases, which are widely distributed among bacteria, fungi and higher plants. Crystals of a family 16 endo-1,3-beta-glucanase from the alkaliphilic Nocardiopsis sp. strain F96 were obtained by the hanging-drop vapour-diffusion method. The crystals belonged to space group P2(1), with unit-cell parameters a = 34.59, b = 71.84, c = 39.67 A, beta = 90.21 degrees, and contained one molecule per asymmetric unit. The Matthews coefficient (VM) and solvent content were 1.8 A3 Da(-1) and 31.8%, respectively. Diffraction data were collected to a resolution of 1.3 A and gave a data set with an overall Rmerge of 6.4% and a completeness of 99.3%.

Actinomycetales↗
PubMed1998

SPECT brain imaging in epilepsy: a meta-analysis.

UNLABELLED: A meta-analysis of SPECT brain imaging in epilepsy was performed to derive the sensitivity and specificity of interictal, postictal or ictal rCBF patterns to identify a seizure focus in medically refractory patients. METHODS: Papers were obtained by pooling all published articles identified by two independent literature searches: (a) Dialnet (EMBASE) or Radline by CD-ROM and (b) Current Contents searched manually. Literature inclusion criteria were: (a) patients had a localization-related epileptic syndrome; (b) more than six patients were reported; and (c) patients had at least an interictal EEG-documented epileptiform abnormality. Of 46 papers meeting these criteria, 30 contained extractable data. SPECT results were compared to localization by standard diagnostic evaluation and surgical outcome. Meta-analytic sensitivities for SPECT localization in patients with temporal lobe seizures relative to diagnostic evaluation were 0.44 (interictal), 0.75 (postictal) and 0.97 (ictal). Similar results were obtained relative to surgical outcome. False-positive rates were low relative to diagnostic evaluation (7.4% for interictal and 1.5% for postictal studies) and surgical outcome (4.4% for interictal and 0.0% for postictal studies). RESULTS: The results were not dependent on tracer used (or dose), the presence of CT-identified structural abnormalities, blinding of image interpretation or camera quality (although data were more variable with low-resolution cameras). There were insufficient data for conclusions regarding extratemporal-seizure or pediatric epilepsy populations. CONCLUSION: Insights gained from reviewing this literature yielded recommendations for minimal information that should be provided in future reports. Additional recommendations regarding the nature and focus of future studies also are provided. The most important of these is that institutions using SPECT imaging in epilepsy should perform ictal, preferably, or postictal scanning in combination with interictal scanning.

Brain↗
PubMed1972

The three-dimensional structure of yeast phenylalanine transfer RNA: shape of the molecule at 5.5-A resolution.

Three isomorphous heavy-atom derivatives have been obtained of orthorhombic crystals of phenylalanine transfer RNA from yeast. These derivatives contain osmium, samarium, and platinum. The positions of the heavy atoms have been determined; these have been used to calculate a three-dimensional electron-density map of transfer RNA at a resolution of 5.5 A. The map shows a high contrast between the molecular boundaries and the solvent areas, so that most of the external shape of the molecule can be determined. The molecule appears to be 92 A long and to have a width varying from 16 A to 34 A. There are some narrow regions in the molecule that connect more globular regions. The electron density map shows chains of dense objects approximately 6 A apart that are probably due to adjacent phosphate groups on the polynucleotide chain. At the present stage of the analysis it is not possible to trace the entire backbone unambiguously; however, the data at this resolution suggest no apparent similarity between the folding of the molecule and any of the tertiary structure models proposed for transfer RNA.

Models, Structural↗
PubMed1996

Electron-crystallographic refinement of the structure of bacteriorhodopsin.

Using electron diffraction data corrected for diffuse scattering together with additional phase information from 30 new images of tilted specimens, an improved experimental density map has been calculated for bacteriorhodopsin. The atomic model has then been rebuilt into this new map with particular attention to the surface loops. All the residues from 7 to 227 as well as ten lipid molecules are now included, although a few amino acid residues in three of the six surface loops, about half of the lipid hydrophobic chains and all of the lipid head groups are disordered. The model has then been refined against the experimental diffraction amplitudes to an R-factor of 28% at 3.5 angstrom resolution with strict geometry (0.005 angstrom) bond length deviation) using the improvement of the "free" phase residual between calculated and experimental phases from images as an objective criterion of accuracy. For the refinement some new programs were developed to restrain the number of parameters, to be compatible with the limited resolution of our data. In the final refined model of the protein (2BRD), compared with earlier co-ordinates (1BRD), helix D has been moved towards the cytoplasm by almost 4 angstrom, and the overall accuracy of the co-ordinates of residues in the other six helices has been improved. As a result the positions of nearly all the important residues in bacteriorhodopsin are now well determined. In particular, the buried, protonated Asp115 is 7 angstrom from, and so not in contact with, the retinal and Met118 forms a cap on the pocket occupied by the beta-ionone ring. No clear density exists for the side-chain of Arg82, which forms a central part of the extracellular half-channel. The only arginine side-chain built into good density is that of Arg134 at the extracellular end of helix E, the others being disordered near one of the two surfaces. The interpretation of the end of helix F on the extracellular surface is now clearer; an extra loose helical turn has been built bringing the side-chain of Glu194 close to Arg134 to form a probable salt bridge. The model provides an improved framework for understanding the mechanism of the light-driven proton pumping. A number of cavities that could contain water molecules were found by searching the refined model, most of them above or below the Schiff base in the half-channels leading to the two surfaces. The ordered and disordered regions of the structure are described by the temperature factor distribution.

Amino Acid Sequence↗
PubMedDate not supplied

Biochemical characterization of rat intestine development using high-resolution magic-angle-spinning 1H NMR spectroscopy and multivariate data analysis.

We report details of metabolic profiles for small intestinal samples obtained using high-resolution magic-angle-spinning (HRMAS) (1)H NMR spectroscopy. Intact samples of jejunum and ileum from male Long Evans rats were analyzed on a 600 MHz spectrometer using standard one and two-dimensional (1)H NMR spectroscopic pulse sequences. The metabolic profiles of ileum and jejunum predominantly comprised a number of amino acids, lipids, glycerophosphocholine (GPC), choline, creatine, and ethanol, a number of carboxylic acids including acetate and lactate, and nucleoside bases including cytosine, isocytosine, and uracil. Principal component analysis (PCA) was applied to these NMR data to characterize the biochemical differences between jejunum and ileum tissues. Compared with ileum, jejunum contained higher levels of lipids, GPC, choline, lactate and creatinine, but lower levels of amino acids and acetate. In addition, the age dependence of the biochemical composition of intestinal tissues from young rats (15, 36 days and 3-4 months old) was studied. In general, levels of lipids, lactate, taurine and creatinine were positively correlated with age while amino acids and GPC decreased in the older age group. This study will provide a metabolic reference for further studies assessing the metabolic consequences of nutrition, stress and gut microbiota on intestinal composition.

Age Factors↗