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T Ookawara

Publications and source records attributed to T Ookawara.

At least 19 recordsLinked to original sources
PubMed2003

Extracellular superoxide dismutase following cerebral ischemia in mice.

We describe the changes in extracellular superoxide dismutase (EC-SOD) following cerebral ischemia in mice. Mice were subjected to transient forebrain ischemia and reperfusion. The measurements of EC-SOD using ELISA showed increased brain EC-SOD after 24 h of reperfusion. The immunohistochemical examination showed that EC-SOD immunoreactivity in cortical and striatal capillary wall was conspicuous after 3 h. EC-SOD immunoreactivity was also noted in cortical neurons after 24 h. Northern blot analysis showed an increased EC-SOD mRNA expression in the brain after 24 h. In situ hybridization study demonstrated no mRNA expression of EC-SOD following ischemia and reperfusion in the capillary wall. These findings suggest that serum EC-SOD might accumulate on brain endothelial cells, while cortical neurons produce EC-SOD themselves after cerebral ischemia with reperfusion.

Animals↗
PubMed2001

Negative regulation of LPS-stimulated expression of inducible nitric oxide synthase by AP-1 in macrophage cell line J774A.1.

The level of NOS II mRNA was markedly increased during 24 h lipopolysaccharide (LPS) stimulation, but showed no further increase thereafter. On the other hand, the level of NOS II mRNA in J774A.1 cells transfected with an expression vector containing the rat csk cDNA (J.Csk) was significantly increased during 3 h LPS stimulation, but rather decreased thereafter. Although no significant difference was observed in the activation of NF-kappaB by LPS among parental J774A.1, J774A.1 transfected with promoterless vector (J.pBK), and J.Csk cells, activity of c-Jun N-terminal kinase (JNK) and nuclear translocation of nuclear factor activator protein-1 (AP-1) were markedly upregulated in the J.Csk cells. Then luciferase reporter vectors containing NOS II promoter with mutations in two AP-1-like sites (U site, -1126 approximately -1120; L site, -524 approximately -518) were transiently transfected in J774A.1 cells. The promoter activity following LPS stimulation for 24 h was significantly increased by mutation at the L site, but not by mutation at the U site, suggesting that NOS II expression is negatively regulated, at least in part, through the AP-1-like L site in response to LPS.

Animals↗
PubMed2001

Superoxide dismutase gene expression is activated by a single bout of exercise in rat skeletal muscle.

The goal of this experiment was to examine contraction-mediated activation of superoxide dismutase (SOD) gene expression in rat superficial vastus lateralis (SVL, type IIb) and deep vastus lateralis (DVL, type IIa) muscles. Female Sprague-Dawley rats were randomly divided into exercise (E) and control (C) groups that were sacrificed at 0, 1, 2, 4, 10, 24, and 48 h (n=6) following an acute bout of treadmill exercise (25 m/min, 5% grade) to exhaustion (running time approximately equals 1 h). Nuclear factor-kappaB (NF-kappaB) in DVL and SVL showed maximal binding at 2 and 10 h respectively, and remained elevated. Activator protein-1 (AP-1) showed maximal binding at 1 h post-exercise, and returned to resting levels at 10 h in both muscles. Mn SOD mRNA abundance in the DVL was increased at 0 (P<0.01), 1, and 2 h (P<0.05) post-exercise, whereas Mn SOD protein was unchanged. In SVL, Mn SOD mRNA abundance was not altered by exercise, whereas Mn SOD protein content was increased at 10 (P<0.05) and 24 h (P<0.075) post-exercise. CuZn SOD mRNA was unchanged with exercise in DVL and SVL, but CuZn SOD protein was elevated 48 h after exercise in both DVL and SVL (P<0.01). Activities of Mn SOD, CuZn SOD and total SOD showed no change with exercise in either muscle examined. These findings indicate that an acute bout of exercise can increase binding of NF-kappaB and AP-1 in both SVL and DVL, which may stimulate Mn SOD mRNA transcription in the more oxidative type DVL muscle. The increased CuZn SOD protein contents seen post-exercise, without increases in mRNA abundance in both DVL and SVL, suggest a translational mechanism in this SOD isoform.

Animals↗
PubMed2001

Characteristics of plasma extracellular SOD in burned patients.

The aim of this study was to examine three types of superoxide dismutase (SOD) in plasma after burns, and especially to clarify the characteristics of plasma extracellular SOD (EC-SOD) in burned patients. A total of 71 blood samples were collected from 18 patients on arrival, day 1, day 3 and day 5 after burns. We measured three types of SOD (Mn, Cu/Zn, EC) in plasma using ELISA, and the relationships among the three types of SOD concentrations were examined. We next analyzed the characteristics of plasma EC-SOD using stepwise multivariate regression analysis. Any plasma SOD isoenzyme concentration measured after burns was beyond the normal range and EC-SOD accounted for the major part of plasma SODs. EC-SOD and Cu/Zn-SOD were positively correlated, whereas Mn-SOD was not related to the other SODs. Also, plasma EC-SOD was significantly related to existence of inhalation injury, %TBSA and age, respectively. The plasma EC-SOD might therefore play some roles in the pathophysiology of burned patients.

Adult↗
PubMed2001

Presence of Vicia graminea or Vicia unijuga lectin-binding (Vgu) glycoproteins with and without Thomsen-Friedenreich (T) antigen in normal human seminal plasma.

Vgu glycoprotein (Vicia graminea lectin- or Vicia unijuga lectin-binding glycoprotein) has been reported as oncofetal antigen, which is found in many kind of tumor tissues, amniotic fluid and fetal membranes. In autoradiography with an 125I-labeled Vicia unijuga lectin (VUA) probe and an 125I-labeled Arachis hypogaea lectin (PNA, anti-T lectin) probe, seminal plasma samples of eight healthy men gave 2-7 Vgu glycoproteins without T antigen, 1-2 Vgu glycoproteins with Thomsen-Friedenreich antigen (T antigen) and 1-8 T-antigen glycoproteins, respectively. These results show that in addition to T-antigen glycoproteins, normal human seminal plasma contains Vgu glycoproteins and Vgu glycoproteins with T antigen as seminal plasma components as well as other tumor markers such as CA19-9, CA-125 and CEA.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed2000

Superoxide dismutase gene expression in skeletal muscle: fiber-specific effect of age.

The influence of ageing on the expression of two superoxide dismutase (SOD) isozymes was examined in three different skeletal muscle fiber types of young (Y, 8 mo) and old (O, 25 mo) rats. Total SOD activity was increased with age in the gastrocnemius (Gas, type II(mix)) and superficial vastus lateralis (SVL, type IIb) but unchanged in the soleus (Sol, type I). The increased SOD activity in SVL was due to increased cytosolic SOD (CuZn SOD), whereas both mitochondrial (Mn SOD) and CuZn SOD activities were increased in Gas. In Sol, Mn SOD activity was significantly increased in aged rats. Mn SOD mRNA level was significantly decreased with age in all three muscles examined, while Mn SOD protein content was not altered. Ageing did not affect CuZn SOD mRNA abundance in any of the muscles, but significantly increased CuZn SOD protein content in aged Gas and Sol. Binding of two redox-sensitive transcription factors, nuclear factor-kappaB (NFkappaB) and activator protein-1 (AP-1) was significantly decreased with age in all three muscle types. These results indicate that increased SOD activity in aged skeletal muscle is not associated with higher levels of gene transcription. Increases in Mn SOD activity seen in aged Gas and Sol are the result of post-translational modification of the enzyme, whereas increases in CuZn SOD activity during ageing may be due to both translational and post-translational control.

Aging↗
PubMed2000

The contribution of fructose and nitric oxide to oxidative stress in hamster islet tumor (HIT) cells through the inactivation of glutathione peroxidase.

Reducing sugars, such as glucose and fructose, are known to play a role in the initiation of apoptosis in pancreatic beta-cells. The data collected in this study show that fructose increases H2O2 levels and lipid peroxidation of hamster islet tumor (HIT) cells, which originated from hamster pancreatic beta-cells. In an attempt to clarify the mechanism of this oxidative stress, we were able to show that glutathione peroxidase (GPx) is inactivated by fructose, and that mRNA expression of GPx is suppressed by fructose. Nitric oxide (NO) is also known to bring about apoptosis. The presence of NO increases intracellular peroxide levels in HIT cells as judged by flow cytometric analysis. These data suggest that fructose and nitric oxide suppress the activity or expression of GPx, and, as a result, permit an increase in intracellular peroxides or lipid peroxidation. This represents a major contribution to the main mechanism of apoptosis by fructose and NO.

Adenoma, Islet Cell↗
PubMed2000

Inhibition of adipocyte lipolysis by papaverine: papaverine can inhibit the redistribution of hormone-sensitive lipase.

Papaverine, despite being a potent phosphodiesterase inhibitor, actually blocks adipocyte lipolysis. The present study was designed to clarify the mechanism of the inhibitory effect of papaverine on lipolysis. Lipolysis, stimulated by either 10 microM isoproterenol or 5 mM dibutyryl cAMP, was significantly inhibited by papaverine (100 microM and above). Papaverine, however, did not affect the isoproterenol-induced increase in the protein kinase A (A-kinase) activity ratio. In cell-free extract from non-stimulated adipocytes, cAMP-stimulated A-kinase activities were almost completely blocked by H-89, a potent inhibitor of A-kinase, but not by papaverine. Thus, the inhibitory effect of papaverine on lipolysis could be responsible for a deficit in step(s) distal to A-kinase activity. Hormone-sensitive lipase activities in the infranatant fraction of centrifuged homogenates of cells, which were maximally stimulated with isoproterenol were significantly reduced. This result indicates that hormone-sensitive lipase redistributes from cytosol to its substrate in lipolytically stimulated cells. Papaverine completely blocked the isoproterenol-induced decrease in lipase activity in the infranatant fraction. These results suggest that papaverine blocks lipolysis through its inhibitory effect on the redistribution of hormone-sensitive lipase.

Adipocytes↗
PubMed2000

Effects of ageing on generation of ED2high major histocompatibility complex class II+ macrophages during cold stress.

The effects of cold stress (5 degrees C, 24 h) were investigated on the function and surface phenotype of peritoneal cells in the monocyte/macrophage lineage from young (8-10-week-old) and old (22-24-month-old) rats. The role of glucocorticoid (GC) in the immunomodulation by cold stress was also examined. The proportion of cells with a high density of ED2 (ED2high cells), expressing major histocompatibility complex (MHC) class II molecules, was significantly increased in peritoneal cells during cold stress in young, but not in old, rats. Antigen-presenting function was significantly higher in ED2high cells than in cells with a low density of ED2 (ED2low cells), thereby indicating that ED2high cells are at a functionally high level. While serum corticosterone concentration in old rats increased markedly after 3 h of cold stress, that in young rats did not vary substantially, and was followed by a significant decrease in both groups of rats after 24 h of cold stress. Administration of dexamethasone to young rats completely inhibited the increase of ED2high cells caused by cold stress. Meanwhile, the proportion of ED2high cells in young rats was significantly increased by adrenalectomy. Furthermore, nuclear translocation of a large amount of the GC receptor was observed in ED2low cells. These results suggest that cold stress enhances immune function in young rats, but not in old rats, and that the generation of ED2high cells are partly regulated by circulating GC level.

Adrenalectomy↗
PubMed2000

Extracellular superoxide dismutase in tissues from obese (ob/ob) mice.

We have examined the protein content and gene expression of three superoxide dismutase (SOD) isoenzymes in eight tissues from obese ob/ob mice, particularly placing the focus on extracellular-SOD (EC-SOD) in the white adipose tissue (WAT). Obesity significantly increased EC-SOD level in liver, kidney, testis, gastrocnemius muscle, WAT, brown adipose tissue (BAT), and plasma, but significantly decreased the isoenzyme level in lung. Tumor necrosis factor-alpha and interleukin-1beta contents in WAT were significantly higher in obese mice than in lean control mice. Immunohistochemically, both WAT and BAT from obese mice could be stained deeply with anti-mouse EC-SOD antibody compared with those from lean mice. Each primary culture per se almost time-dependently enhanced EC-SOD production, and overtly expressed its mRNA. The loss of heparin-binding affinity of EC-SOD type C with high affinity for heparin occurred in kidney of obese mice. These results suggest that the physiological importance of this SOD isoenzyme in WAT may be a compensatory adaptation to oxidative stress.

Adipose Tissue↗
PubMed2000

Swimming training prevents generation of suppressor macrophages during acute cold stress.

PURPOSE: Acute cold stress induces suppressor macrophages expressing large numbers of receptors to Fc portion of immunoglobulin G (MAC-1+ Fc gammaRII/IIIbright cells), resulting in suppression of splenocyte mitogenesis. The generation of MAC-1+ Fc gammaRII/IIIbright cells is partly mediated by increased glucocorticoid levels during acute cold stress. The aim of the current study was to investigate the effect of swimming training on the generation of the MAC-1+ Fc gammaRII/IIIbright suppressor macrophages by acute cold stress. METHODS: The trained mice underwent a 6-wk endurance swimming training (5 times/wk) in water at 35-36 degrees C for 90 min. The swimming training significantly increased brown adipose tissue mass, suggesting improved cold tolerance. Actually, when the swimming-trained mice were exposed to 5 degrees C for 3 h (acute cold stress), the rectal temperature was not decreased. The proportion of MAC-1+ Fc gammaRII/IIIbright cells in peritoneal exudate cells from swimming-trained mice was significantly lower than that from control mice. In addition, the proportion of MAC-1+ Fc gammaRII/IIIbright cells in peritoneal exudate cell population from swimming-trained mice was unaffected by the acute cold stress. The swimming training significantly attenuated the increases in serum corticosterone levels in response to acute cold stress. These results suggested that swimming training not only improves cold tolerance but also inhibits the generation of suppressor macrophages under acute cold stress as well as under normal conditions.

Acclimatization↗
PubMed2000

Effects of swimming training on three superoxide dismutase isoenzymes in mouse tissues.

The purpose of the present study was to investigate the effects of swimming training on the changes in three superoxide dismutase (SOD) isoenzymes in mice. The trained mice underwent a 6-wk swimming program (1 h/day, 5 days/wk) in water at 35-36 degrees C. Immunoreactive extracellular SOD (EC-SOD), copper- and zinc-containing SOD (CuZn-SOD), and manganese-containing SOD (Mn-SOD) contents and their mRNA abundance were determined in serum, heart, lung, liver, kidney, and gastrocnemius muscle. EC-SOD content in liver and kidney was significantly increased with training. After training, CuZn-SOD content rose significantly only in kidney but decreased significantly in heart, lung, and liver. Mn-SOD content showed a significant increase in lung, kidney, and skeletal muscle but a significant decrease in liver. In most tissues, however, the changes in SOD isoenzyme contents were not concomitant with those in their mRNA levels. The results obtained thus suggest that, except for kidney, the responses in mouse tissues of three SOD isoenzymes (protein levels and mRNA abundance) to swimming training are different and that kidney may be one of the most sensitive organs to adapt to oxidative stress during physical training, although the mechanism remains vague.

Animals↗
PubMed2000

Age-associated increase of basal corticosterone levels decreases ED2high, NF-kappaBhigh activated macrophages.

The proportion of cells with a high density of ED2 (ED2high cells) in peritoneal cells from old rats was significantly lower than that from young rats. The expression of major histocompatibility complex class II (MHC class II) molecules, the antigen presentation, production of interleukin (IL)-1beta and IL-6, and nuclear factor-kappaB activity in ED2high cells were markedly higher than those in cells with a low density of ED2 (ED2low cells), although no significant difference was observed in the expression of MHC class II molecules and the antigen presentation between ED2high cells from young and old rats. Meanwhile, basal corticosterone concentration in serum and glucocorticoid (GC) receptor mRNA expression in peritoneal cells increased significantly in old rats. The proportion of ED2high cells was increased by adrenalectomy in young rats. Furthermore, nuclear translocation of GC receptor was observed in ED2low cells, whereas GC receptor was detected in cytoplasmic extracts from ED2high cells. These results suggest that the decrease in functional ED2high macrophages with age results in the age-associated decline of immune responses, which is regulated, in part, by the basal GC concentration.

Adrenalectomy↗
PubMed2000

Serum extracellular superoxide dismutase in pediatric patients with various diseases as judged by an ELISA.

Extracellular superoxide dismutase (EC-SOD) concentration was measured in sera from 141 patients with 20 forms of infantile diseases including IDDM, SLE and epilepsy, 31 healthy children (controls), and 21 healthy young men by an enzyme-linked immunosorbent assay using a polyclonal antibody against human lung EC-SOD. Serum from patients with IDDM and fever of unknown origin had a significantly (p<0.05) lower concentration of EC-SOD than control serum. Part of sera from patients with the seven forms of diseases (SLE, viral infections, epilepsy, nephrosis, hyperthyroidism, hepatic disease, and Reye syndrome), on the other hand, had a greatly high concentration of EC-SOD, albeit not statistically significant. This SOD isoenzyme profile appears to be specific to each pediatric disease.

Adolescent↗
PubMed1999

Superoxide dismutase gene expression in skeletal muscle: fiber-specific adaptation to endurance training.

The effects of endurance training on the enzyme activity, protein content, and mRNA abundance of Mn and CuZn superoxide dismutase (SOD) were studied in various phenotypes of rat skeletal muscle. Female Sprague-Dawley rats were randomly divided into trained (T, n = 8) and untrained (U, n = 8) groups. Training, consisting of treadmill running at 27 m/min and 12% grade for 2 h/day, 5 days/wk for 10 wk, significantly increased citrate synthase activity (P < 0. 01) in the type I (soleus), type IIa (deep vastus lateralis, DVL), and mixed type II (plantaris) muscles but not in type IIb (superficial vastus lateralis, SVL) muscle. Mitochondrial (Mn) SOD activity was elevated by 80% (P < 0.05) with training in DVL. SVL and plantaris muscle in T rats showed 54 and 42% higher pooled immunoreactive Mn SOD protein content, respectively, than those in U rats. However, no change in Mn SOD mRNA level was found in any of the muscles. CuZn SOD activity, protein content, and mRNA level in general were not affected by training, except for a 160% increase in pooled CuZn SOD protein in SVL. Training also significantly increased glutathione peroxidase and catalase activities (P < 0.05), but only in DVL muscle. These data indicate that training adaptations of Mn SOD and other antioxidant enzymes occur primarily in type IIa fibers, probably as a result of enhanced free radical generation and modest antioxidant capacity. Differential training responses of mRNA, enzyme protein, and activity suggest that separate cellular signals may control pre- and posttranslational regulation of SOD.

Adaptation, Biological↗
PubMed1999

Unloading does not increase brown-adipose-tissue activity in rat pups.

Our previous study has shown that chronic hindlimb suspension leads to an increase in both the thermogenic capacity and the activity in brown adipose tissue (BAT) of adult rats (Yamashita, H., Ohira, Y., Wakatsuki, T., Yamamoto, M., Kizaki, T., Oh-ishi, S., Sato, Y. and Ohno, H. (1995). J. Appl. Physiol. 78: 384-387). In order to examine if unloading also increases the BAT activity in rat pups, the hindlimbs in the suspended pups were unloaded by tail suspension beginning on postnatal day 4 and suspended until day 21. The thermogenic activity (which was assessed by guanosine 5'-diphosphate binding to BAT mitochondria) was markedly lower in 21-day-old suspended pups than in 21-day-old control pups, although there was no difference in uncoupling protein 1 (UCP1) content or UCP1 mRNA expression in the BAT mitochondrial fraction between both pups. Likewise, there was no disparity in either adrenal or thymus mass between the control and suspended pups throughout the experiment. These results suggest that, in contrast to adult rats, chronic hindlimb suspension leads to a decrease in the thermogenic activity in BAT of rat pups possibly for reason that pups are less susceptible to the stress of unloading.

Adipose Tissue, Brown↗