Biomedical subjects

S Iijima

Publications and source records attributed to S Iijima.

299 records · Page 17Linked to original sources

PubMedDate not supplied

Beneficial effect of enteral glycine in intestinal ischemia/reperfusion injury.

It has been shown in vitro that glycine can protect renal tubules and hepatocytes from hypoxic injury. Glycine also attenuates ischemic injury in transplanted livers. The present study investigated the effect of enteral glycine in a murine model of ischemia/reperfusion injury of the small intestine. Mice (n = 12 in each group) were randomized to receive two gastric gavages of either a 20% glycine (Gly) or 23% balanced amino acid (AA) solution with a 6-hour interval between each gavage. One hour after the second gavage, mice underwent superior mesenteric artery clamping for 20 minutes. The clamp was then released for reperfusion. Another group of mice (n = 8) underwent a sham operation and served as additional control animals. Six hours after ischemia/reperfusion, the mice were killed in order to assess the intestinal injury (intestinal protein content, mucosal disaccharidase activity, and intestinal histologic findings) and the systemic consequences (bacterial translocation, serum interleukin-6, and lung myeloperoxidase activity). A second set of mice (n = 55) underwent identical gavages and ischemia/reperfusion and they were followed for survival. Compared to AA, enteral glycine administered prior to intestinal ischemia/reperfusion injury significantly preserved mucosal indices and intestinal histology and decreased lung myeloperoxidase activity. Survival was also significantly increased in animals receiving glycine compared to AA control mice. These data suggest that enteral glycine supplementation may be beneficial in attenuating intestinal ischemia/reperfusion injury and its related systemic effects in this murine model.

Animals↗

PubMedDate not supplied

In vivo assessment of striatal dopamine release in the aged male Fischer 344 rat.

A microdialysis probe was implanted into the striatum of young (4- to 5-month-old) and aged (26- to 27-month-old) Fischer 344 male rats to assess age-related alterations in striatal dopamine (DA) release. Basal levels of DA and the magnitude of DA response evoked by 50 mM and 100 mM high potassium (K+) in aged rats were similar to those in young rats. Furthermore, K(+)-evoked DA release did not correlate with motor performance within either age group. In contrast, amphetamine (250 microM) evoked-DA release of aged rats was significantly lower than that of young rats. Moreover, the enhancement of K(+)-evoked DA release by oxotremorine (500 microM) was significantly attenuated in aged rats. These results indicate that a putative DA release mechanism and its cholinergic modulation of the aged striatum are impaired.

Aging↗

PubMedDate not supplied

Transfer of chromic chloride to embryonic mice and changes in the embryonic mouse neuroepithelium.

Transfer of CrCl3 to embryonic mice and changes in the embryonic mouse neuroepithelium associated with Cr-induced neural tube defects were studied. A single intraperitoneal injection of 51CrCl3 was administered on the 8th day of gestation and animals were killed at various intervals for measurements of radioactivity in the maternal blood and embryos. Radioactivity per gram of fetal tissues increased during the observed period, while those of maternal blood decreased. Pregnant mice were injected intraperitoneally with a single dose of CrCl3 (non-radioactive) on the 8th day of gestation. Animals were killed at specified times after injection and embryos were removed and examined histologically. At 4, 8 and 12 h after injection many pyknotic cells were observed on the neural plate, especially at 8 h after injection. These data suggest that CrCl3 may affect embryos directly and cause neural tube defects and that pyknotic cells on the neural plate may be an early pathological finding in cases of developing exencephaly.

Animals↗

PubMedDate not supplied

Effect of ischemia on hydroxylase cofactor (tetrahydrobiopterin) and monoamine neurotransmitters in rat brain.

Hydroxylase cofactor, monoamine neurotransmitters and their metabolites were measured in ischemic rat brain produced by four-vessel occlusion for 30 and 60 min periods. Slight reduction of hydroxylase cofactor activity was observed in the ischemic cortex after 60 min. Dopamine increased in the brainstem, and its metabolites, 3,4-dihydroxyphenylacetic acid and homovanillic acid, increased throughout the brain. Decrease in norepinephrine was observed in the whole brain. Decrease in serotonin and increase in 5-hydroxyindoleacetic acid, a metabolite of serotonin, was observed in the ischemic cerebral cortex. The present study has revealed that there appears to be no significant relationship between hydroxylase cofactor activity and monoamine levels in the ischemic brain. Thus, the hydroxylase cofactor does not play a main role in regulating monoamine synthesis in the acute phase of brain ischemia.

3,4-Dihydroxyphenylacetic Acid↗

PubMedDate not supplied

Dynamic change of reticuloendothelial system function after surgical stress.

The influence of surgical stress on the function of the reticuloendothelial system (RES) is not well elucidated. Because we established an in vivo functional test for the RES by using chondroitin sulfate iron colloid in rabbits, the normal range of RES function in healthy volunteers (n = 12) and the dynamic change of RES function in surgical patients after distal gastrectomy (n = 14) were examined by this method. In healthy volunteers, the maximum phagocytic velocity and membrane-particle constant were 0.0310 +/- 0.0052 mg/kg per minute and 0.575 +/- 0.205 mg/kg, respectively. In surgical patients, maximum phagocytic velocity (postoperative day 1, 0.0408 +/- 0.0088; postoperative day 3, 0.0486 +/- 0.0115; and postoperative day 7, 0.0430 +/- 0.0115 mg/kg per minute) and membrane-particle constant (postoperative day 3, 0.717 +/- 0.169 mg/kg) significantly increased postoperatively in comparison with preoperative values. These results indicate that the total capacity of the RES is augmented but that its functional phagocytic efficiency is diminished after abdominal surgery. This phenomenon is considered to be one of the immunological alterations caused by surgical stress. The chondroitin sulfate iron colloid test can be applied to monitor the dynamic change of the RES function under various conditions.

Adult↗

PubMedDate not supplied

Intravenous administration of nucleosides and a nucleotide mixture diminishes intestinal mucosal atrophy induced by total parenteral nutrition.

Total parenteral nutrition (TPN) is associated with atrophic changes in the structure and function of the intestinal mucosa. Because rapidly renewing intestinal mucosal cells may require an external source of purines and pyrimidines for their optimal growth, it can be assumed that supplementation of nucleosides and a nucleotide mixture (OG-VI) during TPN may prevent the progression of mucosal atrophy by compensating for a relatively insufficient delivery from liver. To test that hypothesis, male Wistar rats receiving TPN for 7 days were divided into four groups according to different TPN solutions. Group C (n = 10) received a standard solution, group O (n = 10) received OG-VI in addition to the standard solution, and group G (n = 10) received a glutamine-rich TPN solution containing almost the same amount of calories and nitrogen as the standard solution. Group O+G (n = 10) received OG-VI in addition to the glutamine-rich solution. Various parameters were examined on the eighth day in the jejunal and ileal segments. The following significant changes in comparison with group C were observed: total wet weight of the jejunal segment in group O was significantly greater, as was mucosal wet weight of the jejunal and ileal segments in groups O and O+G; protein contents of the ileal segment in group O as well as the DNA content of the jejunal segment in group O increased significantly; and maltase activity of the jejunal segment in group O+G increased, as did the villus height of the jejunal segment in groups O and O+G and the villus height of the ileal segment in group G.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMedDate not supplied

Interrelation of intracellular proteases with total parenteral nutrition-induced gut mucosal atrophy and increase of mucosal macromolecular transmission in rats.

Total parenteral nutrition (TPN) is known to induce mucosal atrophy and to increase macromolecular transmission of the small intestine. The potential participation of various proteases in that process was investigated. Male Wistar rats were randomly divided into two groups: the TPN group (n = 11) received a standard TPN (250 kcal/kg per day, 1.78 g nitrogen/kg per day) and the FED group (n = 10) received a standard rat food for 1 week. This was followed by an examination of gut macromolecular transmission of fluorescein isothiocyanate dextran 70,000 (FITC-dextran) after intragastric injection and of the activities of gut mucosal cathepsins B, H, and L and of proteasome. Mucosal wet weight and protein content decreased significantly by TPN for 1 week. In both groups, the activities of all proteases in the ileum were significantly greater than in the jejunum. In the TPN group, cathepsin L and H activities in the ileum, and cathepsin B activity in both the jejunum and the ileum, were greater than those in the FED group. The portal concentration of FITC-dextran was higher than arterial and venous concentrations in the both groups. In the TPN group, the portal FITC-dextran concentration increased significantly compared with the FED group. In conclusion, active proteolysis is not associated with TPN-induced mucosal atrophy. Cathepsins activities in the ileum increase as a result of TPN. Interrelationship is implicated between increase of lysosomal protease activity and the deterioration of the intestinal barrier function, which permits macromolecular transmission.

Animals↗

PubMedDate not supplied

Effects of nucleosides and a nucleotide mixture on gut mucosal barrier function on parenteral nutrition in rats.

BACKGROUND: We have previously reported that the addition of nucleosides and a nucleotide mixture (OG-VI) to total parenteral nutrition (TPN) prevents TPN-induced intestinal mucosal atrophy and results in increased intestinal cathepsin activities under TPN. The aims of the present study are to examine the effects of OG-VI on mucosal barrier functions and to clarify whether the intestinal cathepsins can be used as a new marker of mucosal barrier function. METHODS: Male Wistar rats were divided into three groups: FED (food ad libitum), TPN (a standard TPN solution), and OG (OG-VI in addition to the TPN solution). Mucosal barrier functions were analyzed by the lactulose/mannitol (L/M) test, mucosal ZO-1 messenger RNA level, and electron micrographs in the gut. Intestinal cathepsin B, H, and L activities were also measured. RESULTS: The L/M ratio for TPN was much higher than that for FED. Only lactulose excretion was significantly reduced by OG-VI. The intercellular spaces of the mucosal cells for TPN were significantly wider than those for FED, but were reduced in size by the addition of OG-VI. All cathepsin activities of the ileum were higher for TPN than for FED, whereas OG showed no increase. CONCLUSION: OG-VI contributes to the improvement of gut mucosal barrier function. Intestinal cathepsin activities can be used as a new marker of mucosal barrier function.

Animals↗

PubMedDate not supplied

Nucleotides and intestine.

BACKGROUND: Dietary nucleotides play an important role in the growth and development of the intestine. Parenteral supplementation of nucleic acids may be necessary to maintain the mucosal proliferation and barrier functions during parenteral nutrition (PN). METHODS: Male Wistar rats were divided into 3 groups: FED (food ad libitum with saline infusion); PN (a standard PN solution); and OG (OG-6, a mixture of nucleotide and nucleosides, in addition to the PN solution). The mucosal wet weight, protein, and DNA contents, villous height and crypt depth, electronmicroscopic examination of the intercellular junctions, proliferating activity of the mucosal cells, mucosal permeability, bacterial translocation, and mucosal cathepsin activities were examined. RESULTS: The wet weight, protein, and DNA contents of the jejunal mucosa were significantly increased in the OG group, compared with those in the PN group. The morphometric examination revealed a significant increase in the villous height but not in the crypt depth in the OG group. The widths of both the tight and intermediate junctions were narrower in the OG group than those in the PN group. The activity of diamine oxidase was increased in the OG group, compared with that in the PN group. The ratio of proliferating cell nuclear antigen positive cells and the index of bromodeoxy uridine labeling index in the OG group were as high as in the FED group, and significantly higher than those in the PN group. The portal concentration of fluorescein isothiocyanate-dextran 70,000 after intragastric loading was significantly higher in the PN group than that in OG group. Likewise, the rate of urinary lactulose excretion after intragastric loading was higher in the PN group. The positive rate of bacteria cultured in mesenteric lymph nodes was higher in the PN group than in the OG group although the difference was not significant. The activities of mucosal cathepsins (B, H, and L), markers for phagocytic degradation of extrinsic substances and organisms, were higher in the PN group than those in the OG and FED groups. CONCLUSIONS: Parenteral supplementation of nucleic acids supports the mucosal cell proliferation and functions.

Administration, Oral↗

PubMedDate not supplied

Plasma and erythrocyte magnesium concentrations in thyroid disease: relation to thyroid function and the duration of illness.

To clarify magnesium metabolism in thyroid dysfunction, plasma and erythrocyte magnesium concentrations (P-Mg, E-Mg) were determined in patients with untreated thyroid diseases and their relations to thyroid hormone levels and the duration of illness were examined. P-Mg was significantly lower in hyperthyroid patients than in euthyroid or hypothyroid individuals. E-Mg was significantly higher in hypothyroid patients than in hyperthyroid or euthyroid individuals. In the entire series of 84 subjects, both P-Mg and E-Mg showed significant negative correlations with thyroid hormone levels, but the correlations were greater in P-Mg than E-Mg. In hyperthyroid patients, both P-Mg and E-Mg were negatively correlated with the duration of illness, but this correlation was greater in E-Mg than P-Mg. Also, both P-Mg and E-Mg were significantly higher in patients with destructive thyroiditis with a short duration (0.5 months) such as subacute or painless thyroiditis than in patients with Graves' disease (4.9 months). These results suggest that magnesium metabolism in thyroid dysfunction is affected not only by thyroid hormone levels but also by the duration of illness.

Acute Disease↗

PubMedDate not supplied

Role of nucleosides and nucleotide mixture in intestinal mucosal growth under total parenteral nutrition.

The preventive effect of a mixture of nucleosides and a nucleotide (OG-VI) on total parenteral nutrition (TPN)-associated gut mucosal atrophy was investigated. Male Wistar rats were randomly divided into two groups. The TPN group (n = 11) received a standard TPN diet (250 kcal and 1.78 g nitrogen.kg-1.day-1) for 6 days; the TPN + OG-VI group (n = 10) received OG-VI (2.5 ml.kg-1.day-1) in addition to the standard TPN solution for 6 days. To obtain information on a normal fed condition of the intestine, another 10 rats were maintained on oral rat chow for 6 days. Compared with the TPN group, mucosal wet weights in the jejunum (22.8 +/- 1.8 vs. 20.5 +/- 2.0 mg/cm) and the ileum (19.4 +/- 2.2 vs. 16.8 +/- 2.3 mg/cm) were significantly greater in the TPN + OG-VI group. Likewise, diamine oxidase activities in the jejunum (13.7 +/- 4.27 vs. 8.02 +/- 3.40 nmol.min-1.cm-1) and the ileum (33.9 +/- 6.89 vs. 25.9 +/- 7.93 nmol.min-1.cm-1) were significantly higher in the TPN + OG-VI group. Moreover, the bromodeoxyuridine labeling index in the TPN + OG-VI group (36.9 +/- 4.30%) was significantly higher than in the TPN group (31.0 +/- 3.03%). The addition of OG-VI to the standard TPN diet improved mucosal growth and maturity by increasing the proliferating activity of crypt cells. External provision of purines and pyrimidines may be necessary to sustain mucosal function during TPN.

Amine Oxidase (Copper-Containing)↗