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Nmol/mg Protein (nmol/mg + protein)
Selected AbstractsSignificance of determining the point of reperfusion failure in experimental torsion of testisINTERNATIONAL JOURNAL OF UROLOGY, Issue 1 2005ELIJAH O KEHINDE Abstract Background:, Experimental studies of the use of free radical scavengers in ischemic/reperfusion (I/R) injury following detorsion of the torted testis have yielded conflicting results due to differences in the period of ischemia used. The authors studied I/R injury in the rabbit model, to define the point beyond which there is reperfusion failure. Methods:, Ischemia/reperfusion injury of the testis was created in 3,6-month-old male New Zealand white rabbits by cross-clamping the left spermatic cord for periods of ischemia lasting 0, 15, 30, 60, 90, 120 and 180 min. There were eight animals per experimental group. The right testis served as internal control. Both testes were harvested after 24 h of reperfusion in four animals and after 3 months in the remaining four animals for each group. Testicular malondialdehyde (MDA), a measure of free radical damage, was determined by using the thiobarbituric acid reaction on testicular homogenates. Johnsen score was used to assess morphological damage caused by the ischemia. Results:, After 24 h of reperfusion, the mean testicular MDA in the control right testes at 0, 15, 30, 60, 90, 120 and 180 min was 2.1, 2.5, 2.9, 2.4, 2.1 and 1.9 nmol/mg protein, respectively. The mean left testicular MDA at corresponding ischemic periods was 1.6, 2.0, 3.9, 10.0, 4.4, 6.1 and 1.0 nmol/mg protein, respectively. The maximum left testicular MDA was at 60 min (10.0 nmol/mg protein), following which the level dropped significantly to 1.0 nmol/mg protein at 180 min. At 3 months, the mean Johnsen scores for left testes subjected to 0, 60, 120 and 180 min ischemia were 9.4, 8.8, 2.3, 3.5, respectively. Conclusion:, The results suggest that following ischemia of up to 60 min in the rabbit testis, adequate reperfusion is possible, but ischemia lasting beyond 60 min results in inadequate reperfusion leading to irreversible damage. Thus, in experiments for assessing the effect of antioxidants on I/R injury of the testis in rabbits, periods up to 60 min of ischemia should be regarded as optimum to observe an effect. [source] In vitro studies on the effects of Saccharomyces boulardii and Bacillus cereus var. toyoi on nutrient transport in pig jejunumJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 1-2 2000G. Breves The probiotics Saccharomyces boulardii and Bacillus cereus var. toyoi are nonpathogenic microbes which have been shown to affect certain functions of the mucosal barrier in pig jejunum such as electrogenic ion transport capacity and paracellular permeability. The present studies were performed to investigate potential effects of the probiotics on jejunal nutrient transport such as sodium-dependent glucose transport or proton-dependent dipeptide transport. For this purpose the in vitro Ussing-chamber technique was applied in order to examine net electrogenic ion flux rates (short circuit currents, Isc) across isolated intact jejunal epithelia in the absence and presence of either 10 mmol/l glucose (mucosal side) or two-fold application of 5 mmol/l glycyl- l -sarcosine or glycyl- l -glutamine to the mucosal bathing solution. Brush border membrane vesicles (BBMV) were prepared in order to characterize kinetic parameters (Vmax, Km) of Na-dependent glucose transport. Intestinal tissues were obtained from growing pigs in a weight range between 23 and 33 kg. All animals were fed twice daily and received 0.8,0.9 kg/day of a standard diet. After a 9- to 10-day adaptation period the diets for treated animals were either supplemented for 8 days with 1.7×107 colony-forming units (CFU)/g feed of S. boulardii or for 3 weeks with 106 CFU/g feed B. cereus var. toyoi. Under basal conditions Isc values were not affected by different treatment protocols (controls: 0.74 ± 0.04 µeq/cm2 per h, n=9; S. boulardii: 0.74 ± 0.12 µeq/cm2 per h, n=7; B. cereus 0.68 ± 0.09 µeq/cm2 per h, n=5). Irrespective of dietary treatment, the addition of glucose resulted in significant increases of Isc indicating substantial onset of electrogenic net Na/glucose cotransport. Maximal Isc values occurred within 30 min and reached 2.79 ± 0.41 µeq/cm2 per h in control epithelia. This was significantly lower than found in S. boulardii (4.47 ± 0.43 µeq/cm2 per h, p < 0.05) and B. cereus var. toyoi tissues (4.45 ± 0.31 µeq/cm2 per h, p < 0.05). Gt values were 22.4 ± 1.3 mS/cm2 in control animals and were significantly lower as shown in S. boulardii (p < 0.01) and B. cereus var. toyoi (p < 0.01)-treated animals (28.4 ± 1.3 and 29.9 ± 0.8 mS/cm2, respectively). Vmax values of Na-dependent glucose uptake into BBMV differed significantly between controls (0.64 ± 0.08 nmol/mg protein per 10 s; n=5), S. boulardii (0.89 ± 0.06 nmol/mg protein per 10 s; n=5, p < 0.05) and B. cereus var. toyoi preparations (1.08 ± 0.05 nmol/mg protein per 10 s; n=3, p < 0.01). Km values were not significantly affected (control: 0.31 ± 0.04 mmol/l, S. boulardii: 0.29 ± 0.05 mmol/l, B. cereus var. toyoi: 0.21 ± 0.01 mmol/l). Irrespective of dietary treatment, application of the dipeptide model substances glycyl- l -sarcosine or glycyl- l -glutamine resulted in significant increases of Isc indicating marked stimulation of electrogenic net H+/dipeptide cotransport. Highest Isc responses occurred in B. cereus var. toyoi preparations and lowest were found in control tissues. However, these differences were not significant. Gt values were not affected by different dietary treatments. The results clearly demonstrate that oral administration of either S. boulardii or B. cereus var. toyoi stimulates Na-dependent glucose absorption in pig jejunum. [source] Effect of endotoxin pretreatment on hepatic stellate cell response to ethanol and acetaldehydeJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 11 2001Silvia C Quiroz Abstract Background and Aim: The role of endotoxin in alcohol-induced liver damage is well recognized. How pre-exposure to endotoxin might affect alcohol injury is not known. We herein studied the effect of endotoxin pretreatment on hepatic stellate cell (HSC) response to ethanol and acetaldehyde. Methods: Rat HSC (CFSC-2G) were exposed to media supplemented with 1 ,g/mL lipopolysaccharide (LPS). This was followed by a 24 h exposure to media containing LPS plus 50 mmol/L ethanol or 175 ,mol/L acetaldehyde. Lipid peroxidation, collagen, and tumor necrosis factor (TNF)-,, interleukin (IL)-1,, IL-6 and transforming growth factor (TGF)-,1 secretion were determined at the end of both periods of exposure. Results: Lipopolysaccharide pretreatment did not modify lipid peroxidation induced by ethanol or acetaldehyde alone. Glutathione (GSH) content decreased to 4.2 ± 0.5 and 16.3 ± 0.8 nmol protein after exposure to ethanol or acetaldehyde alone, and decreased further with LPS pretreatment (2.4 ± 0.2 and 2.7 ± 0.3 nmol/mg protein, respectively). Oxidized GSH (GSSG) content increased in ethanol and acetaldehyde LPS-pretreated cells only. Collagen secretion increased to 988 ± 82 and 1169 ± 91 ,g/106 cells after exposure to acetaldehyde or LPS alone. Lipopolysaccharide pretreatment enhanced collagen secretion significantly in both ethanol- and acetaldehyde-treated cells (969 ± 56 and 1360 ± 72 ,g/106 cells, respectively). Interleukin-6 production increased to 288 ± 48, 1195 ± 86 and 247 ± 35 pg/mL per 106 cells after ethanol, acetaldehyde and LPS exposure, and increased further with LPS pretreatment in ethanol-exposed cells (680 ± 23 pg/mL 106 cells). Conclusion: Lipopolysaccharide pretreatment of HSC adds to the damage produced by ethanol and acetaldehyde by diminishing GSH content and increasing GSSG content, collagen and IL-6 secretion. [source] Gas chromatography,mass spectrometry analysis of endogenous cannabinoids in healthy and tumoral human brain and human cells in cultureJOURNAL OF NEUROCHEMISTRY, Issue 2 2001Mauro Maccarrone Endocannabinoids are lipid mediators thought to modulate central and peripheral neural functions. We report here gas chromatography,electron impact mass spectrometry analysis of human brain, showing that lipid extracts contain anandamide and 2-arachidonoylglycerol (2-AG), the most active endocannabinoids known to date. Human brain also contained the endocannabinoid-like compounds N -oleoylethanolamine, N -palmitoylethanolamine and N -stearoylethanolamine. Anandamide and 2-AG (0.16 ± 0.05 and 0.10 ± 0.05 nmol/mg protein, respectively) represented 7.7% and 4.8% of total endocannabinoid-like compounds, respectively. N -Palmitoyethanolamine was the most abundant (50%), followed by N -oleoyl (23.6%) and N -stearoyl (13.9%) ethanolamines. A similar composition in endocannabinoid-like compounds was found in human neuroblastoma CHP100 and lymphoma U937 cells, and also in rat brain. Remarkably, human meningioma specimens showed an approximately six-fold smaller content of all N -acylethanolamines, but not of 2-AG, and a similar decrease was observed in a human glioblastoma. These ex vivo results fully support the purported roles of endocannabinoids in the nervous system. [source] Study on the pharmacokinetics drug,drug interaction potential of glycyrrhiza uralensis, a traditional Chinese medicine, with lidocaine in ratsPHYTOTHERAPY RESEARCH, Issue 5 2009Jingcheng Tang Abstract Drug,drug interaction potentials of an herbal medicine named Glycyrrhiza uralensis was investigated in rats via in vitro and in vivo pharmacokinetic studies. P450 levels and the metabolic rate of lidocaine in the liver microsomes prepared from different treatment groups were measured. In a separate in vivo pharmacokinetic study, the pharmacokinetic parameters of lidocaine in plasma and urine were estimated. P450 levels in the rats pretreated by Glycyrrhiza uralensis were significant higher than that in the non-treatment control. The increase in P450 levels was dose-dependent. Glycyrrhiza uralensis (1 and 3 g/kg) increased P450 levels by 62% and 91%, respectively, compared with the non-treatment control (0.695 nmol/mg protein). The metabolic rate of lidocaine in the liver microsomes was significantly higher in the herb pretreated rats. The pharmacokinetic profile of lidocaine was significantly modified in the rats with the herbal pretreatment. Elimination half-lives were shortened by 39%, and total clearances were increased by 59% with the pretreatment of Glycyrrhiza uralensis. In conclusion, Glycyrrhiza uralensis showed induction effect on P450 isozymes. Efficacy and safety profiles of a drug may be affected when the herbal products or herbal prescriptions containing the plant medicine were concomitantly used. Copyright © 2009 John Wiley & Sons, Ltd. [source] Eradication of Helicobacter pylori Restores Glutathione S-Transferase Activity and Glutathione Levels in Antral MucosaCANCER SCIENCE, Issue 12 2001Arnoud H. A. M. van Oijen Glutathione S-transferases (GST) and glutathione peroxidases (GPO) are important in detoxification. GST activity in the mucosa of the gastrointestinal tract is inversely correlated with the development of gastrointestinal cancer. Helicobacter pylori (H. pylori) infection has been associated with gastric cancer. We studied GST activity and the substrate glutathione (GSH) in patients with H. pylori-associated gastritis. GST activity and isoenzyme levels, GPO activity and GSH levels were studied in antral biopsies of 38 H./pyfori-positive patients, before and after eradication treatment. In 31 patients in whom H. pylori was successfully eradicated, antral GST enzyme activity before therapy was 532 (465,598) nmol/mg protein-min (mean and 95% confidence interval) and that after therapy was 759 (682,836) nmol/mg protein-min (P<0.0001). Correspondingly, levels of GST , and GST-P1 were higher after eradication (P<0.001). GSH concentration significantly increased: 21.2 (16.2,26.2) nmol/mg protein before and 27.1 (23.6,30.6) nmol/mg protein after therapy (P<0.05). In 7 patients in whom H. pylori was not eradicated, GST activity was 671 (520,823) nmol/mg protein min and 599 (348,850) nmol/mg protein before and after treatment respectively (P=0.32). GSH levels were 17.4 (9.0,25.7) nmol/mg protein and 18.2 (9.1,27.3) nmol/mg protein, respectively (P=0.84). No differences in antral GPO enzyme activity, both of selenium (Se)-dependent and total GPO, before and after successful treatment were found. Eradication of H. pylori infection increases GST activity and GSH levels in antral mucosa. Low GST activity and GSH concentration due to H. pylori infection might play a role in gastric carcinogenesis. [source] | |||||||||||||