Limitation of theophylline elimination by reduced oxygen availability in mouse hepatocytes and rat isolated livers

1985 ◽  
Vol 63 (8) ◽  
pp. 903-907 ◽  
Author(s):  
Kanji Nakatsu
Keyword(s):  
Oxygen Supply ◽  
Correlation Coefficients ◽  
Oxygen Availability ◽  
Isolated Perfused Rat Liver ◽  
Mouse Hepatocyte ◽  
Mouse Hepatocytes ◽  
Per Se ◽  
Theophylline Metabolism ◽  
Effect Of Oxygen ◽  
Rat Livers

The effect of oxygen availability on theophylline metabolism by mouse hepatocytes and rat isolated livers was examined. The elimination of theophylline by mouse hepatocytes and the metabolism of theophylline to dimethyluric acid by isolated, perfused rat livers was seriously impaired when the gas mixture supplied contained less than 28% oxygen. The correlation coefficients relating oxygen supply and the concentration of theophylline remaining in mouse hepatocyte suspensions were −0.74 to −0.84. In the isolated, perfused rat liver experiments, the correlation coefficient relating oxygen availability and dimethyluric acid production was 0.87. These observations are interpreted as supporting the hypothesis that oxygen availability per se is an important factor in determining the rate of theophylline metabolism.

Differential effect of oxygen supply and lactate concentration on keratan sulphate and glycoseminoglycuronan production in bovine cornea

1991 ◽  
Vol 19 (4) ◽  
pp. 354S-354S ◽  
Author(s):  
CESARE BALDUINI ◽  
GLANCARLO DE LUCA ◽  
ALBERTO PASSI ◽  
SIMONETTA RINDI ◽  
ROBERTA SALVINI ◽  
...  
Keyword(s):  
Differential Effect ◽  
Oxygen Supply ◽  
Lactate Concentration ◽  
Keratan Sulphate ◽  
Effect Of Oxygen

Heterosis in relation to genetic divergence in short duration maize (Zea mays L.)

2021 ◽  
pp. 137-142
Author(s):  
Bal Krishna ◽  
Birender Singh ◽  
Shyam Sundar Mandal ◽  
Rashmi Kumari ◽  
Tushar Ranjan
Keyword(s):  
Genetic Distance ◽  
Genetic Divergence ◽  
Zea Mays L ◽  
Correlation Coefficients ◽  
Negative Association ◽  
Coefficient Of Determination ◽  
Maize Hybrids ◽  
Single Cross ◽  
Per Se ◽  
Linear Regressions

Thirteen lines and three testers were used to produce 39 single cross maize hybrids by line Ítester mating design. The genetic divergence among thirteen lines and three tester of maize were estimated by using Mahalanobis D2 statistic for twelve characters. The genotypes were grouped into five clusters. Cluster I comprised 12 parental genotypes (L1, L2, L3, L4, L5; L6, L7, L8, L9, L11; L12, L13), while Cluster II (T3), III (T1), IV (L10) and V (T2) were mono-genotypic, suggesting more variability in genetic makeup of the genotypes included in these clusters. The correlation coefficients and linear regressions were used to know the effects of parental genetic distance in determining heterosis and per se performance of the hybrids. Parental genetic distance exhibited significant negative association and significant linear regression along with very low coefficient of determination with better parent heterosis (BPH) and non-significant with per se performance of the hybrids. The present investigation, therefore, the parental genetic distance has significant role in determining heterosis and hybrid performance in kharif maize.

Effect of oxygen supply on energy metabolism in rats

1994 ◽  
Vol 13 ◽  
pp. 39
Author(s):  
Y. Mimura ◽  
K. Furuya ◽  
J. Maeda ◽  
M. Yamakawa ◽  
T. Oohara
Keyword(s):  
Energy Metabolism ◽  
Oxygen Supply ◽  
Effect Of Oxygen

Perflubron Emulsion in Prolonged Hemorrhagic Shock

2003 ◽  
Vol 98 (6) ◽  
pp. 1391-1399 ◽  
Author(s):  
Markus Paxian ◽  
Hauke Rensing ◽  
Katrin Geckeis ◽  
Inge Bauer ◽  
Darius Kubulus ◽  
...  
Keyword(s):  
Gene Expression ◽  
Glutamine Synthetase ◽  
Adenosine Triphosphate ◽  
Oxygen Supply ◽  
Oxygen Carrier ◽  
Oxygen Availability ◽  
Oxygen Carriers ◽  
Hepatocellular Injury ◽  
Artificial Oxygen Carrier ◽  
Stored Blood

Background Liver dysfunction as a result of impaired oxygen availability frequently occurs following hemorrhage and contributes to delayed mortality. Artificial oxygen carriers may improve oxygen supply to vital organs while avoiding the need for allogeneic transfusion. Methods Rats were subjected to hemorrhagic hypotension (mean arterial pressure = 35-40 mmHg for 120 min) and were subsequently resuscitated with (1) stored whole rat blood, (2) pentastarch, or (3) pentastarch combined with perflubron emulsion (PFE; 2.7 or 5.4 g/kg body weight), a second-generation artificial oxygen carrier. Recovery of liver adenosine triphosphate, hepatocellular injury, and expression of glutamine synthetase 1, a gene that is induced by exposure of hepatocytes to low partial pressure of oxygen, were studied at 4 h of resuscitation. Results Stored whole blood or pentastarch failed to restore liver adenosine triphosphate concentrations after prolonged shock as compared to sham controls and resulted in increased gene expression of glutamine synthetase 1. Addition of 2.7 g PFE/kg restored liver adenosine triphosphate to control, whereas 5.4 g PFE/kg resulted in adenosine triphosphate concentrations significantly above control. Improved hepatocellular oxygen supply was also confirmed by restoration of the physiologic expression pattern of glutamine synthetase 1. Serum enzyme concentrations were highest after resuscitation with stored blood, whereas addition of PFE failed to further decrease enzyme concentrations as compared to pentastarch alone. Conclusions Resuscitation with PFE is superior to stored blood or asanguineous resuscitation with respect to restoration of hepatocellular energy metabolism. The improved hepatocellular oxygen availability is reflected in normalization of oxygen-dependent gene expression. However, improved oxygen availability failed to affect early hepatocellular injury.

scholarly journals In Situ Measurement of Glutamate Concentrations in the Periportal, Intermediate, and Pericentral Zones of Rat Liver

1997 ◽  
Vol 45 (9) ◽  
pp. 1217-1229 ◽  
Author(s):  
Willie J.C. Geerts ◽  
Ard Jonker ◽  
Louis Boon ◽  
Alfred J. Meijer ◽  
Rob Charles ◽  
...  
Keyword(s):  
Rat Liver ◽  
Correlation Coefficients ◽  
Distribution Patterns ◽  
Male Rat ◽  
Linear Relationships ◽  
Adult Male Rat ◽  
Colorimetric Visualization ◽  
Rat Livers ◽  
Cryostat Sections

We developed a quantitative histochemical assay for measurement of local glutamate concentrations in cryostat sections of rat liver. Deamination of glutamate by glutamate dehydrogenase (GDH) was coupled to the production of formazan and formazan precipitation was used for colorimetric visualization. The method was tested and validated with gelatin model sections with known glutamate concentrations. Calibration graphs showed linear relationships with high correlation coefficients (>96%) between glutamate concentrations or section thickness and absorbance values. The method was reproducible, with a constant percentage of 60 ± 5% of glutamate being converted in gelatin model sections containing glutamate concentrations of 2 mM and higher. Glutamate concentrations were estimated in periportal, intermediate, and pericentral zones of liver lobules that contain low, intermediate, and high GDH activity, respectively. In fed adult male rat livers, periportal zones contained the highest concentrations of glutamate (∼14 mM) and intermediate and pericentral zones ∼13 and 9 mM, respectively. On starvation, glutamate concentrations increased only in the small rim of pericentral cells that express glutamine synthetae, to ∼15 mM. In livers of fetal and newborn rats, glutamate was homogeneously distributed, with a concentration of ∼5 mM. In suckling rat liver, distribution of glutamate was still homogeneous but the concentration was increased to ∼8 mM. These glutamate distribution patterns were in agreement with those detected immunohistochemically.

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