Biomedical subjects

Takashi Takeuchi

Publications and source records attributed to Takashi Takeuchi.

At least 37 records · Page 2Linked to original sources

PubMed2004

Suppressive effects of milk-derived lactoferrin on psychological stress in adult rats.

Lactoferrin (LF) is known as an iron-binding glycoprotein. It has been shown that bovine LF (bLF) is transported into cerebrospinal fluid via blood although its physiological effects in the central nervous system (CNS) are still unclear. In this study, a suppressive effect of bLF on psychological distress was investigated in adult rats. Intraperitoneal injection of bLF (100 mg/kg) reduced stressful behaviors in a conditioned fear-induced freezing test and an elevated plus-maze test. Interestingly, the suppressive effect of bLF was enhanced by pretreatment with electric foot-shock (FS). This suppressive effect of bLF in the elevated plus-maze test was reversed by pretreatment with naloxone, an opioid receptor antagonist, at a dose of 1 mg/kg (ip). N(omega)-nitro-l-arginine methyl ester (l-NAME), a nitric oxide synthase (NOS) inhibitor, also blocked the suppressive effect of bLF and foot-shock. In addition, combined application of a low dose of bLF (30 mg/kg, ip) and l-arginine (30 and 100 mg/kg, ip) showed significant potentiated effects on psychological stress. These results suggest that bLF has suppressive effects on psychological distress, especially under the condition of moderate stress. Furthermore, it is suggested that bLF possibly activates an endogenous opioidergic system via nitric oxide synthase activation.

Analysis of Variance↗

PubMed2004

Cardiac abnormalities cause early lethality of jumonji mutant mice.

jumonji (jmj) mutant mice, obtained by a gene trap strategy, showed several morphological abnormalities including neural tube and cardiac defects, and died in utero around embryonic day 11.5 (E11.5). It is unknown what causes the embryonic lethality. Here, we demonstrate that exogenous expression of jmj gene in the heart of jmj mutant mice rescued the morphological phenotypes in the heart, and these embryos survived until E13.5. These results suggest that there are at least two lethal periods in jmj mutant mice, and that cardiac abnormalities may cause the earlier lethality. In addition, the rescue of the cardiac abnormalities by the jmj transgene provided solid evidence that the cardiac abnormalities resulted from mutation of the jmj gene.

Animals↗

PubMed2004

Modifiers of the jumonji mutation downregulate cyclin D1 expression and cardiac cell proliferation.

Cell proliferation is an important factor in various developmental processes in tissue morphogenesis, and is strictly regulated spatiotemporally. jumonji (jmj) deficient mice with a C3H/He background show hyperproliferation of cardiac myocytes and die probably of the phenotype around embryonic day 11.5. Analyses of the abnormalities revealed that repression of cyclin D1 expression by jmj is necessary for downregulation of cardiac myocyte proliferation. On the other hand, jmj mutant mice with a BALB/c background die around E14.5, suggesting that genetic background modifies hyperproliferation in the heart and timing of lethality. Here, we demonstrated that the hyperproliferation was not observed, and that cell proliferation and expression of cyclin D1 were downregulated properly in the cardiac ventricles of jmj mutant mice with a BALB/c background. These results suggest the modifier(s) of the jmj mutation can downregulate cardiac cell proliferation by repressing cyclin D1 expression in the same way as jmj.

Animals↗

PubMed2004

Evidence of lactoferrin transportation into blood circulation from intestine via lymphatic pathway in adult rats.

Using adult rats, the characteristic transporting system for lactoferrin (LF) from intestinal lumen into the blood circulation was investigated. The rats were randomly divided into two groups, a non-collected thoracic lymph (NC) group and a collected thoracic lymph (LC) group. Peripheral blood and thoracic lymph were collected from a jugular vein and a thoracic lymph duct, respectively, under anaesthesia. Bovine LF (bLF) was infused into the duodenal lumen by needle over a 1-min period at a dose of 1 g kg(-1). The transported bLF in the plasma and lymph was assayed quantitatively by double-antibody enzyme-linked immunosorbent assay (ELISA). Morphological investigation was also carried out in the intestine, lymph node, and liver. Following intraduodenal administration of bLF, the transported bLF in the NC group was detected in the plasma, and reached a peak value at 2 h. Furthermore, the bLF concentration in the thoracic duct lymph fluid in the LC group increased significantly, and peaked 2 h after the administration. In addition, bLF was not detected in the plasma of the LC group. Immunohistochemical analysis clearly showed anti-bLF positive particles in the epithelial cells of the apical villi. The striated border and baso-lateral membrane were also bLF positive. These results suggest that intraduodenally infused bLF is transported into the blood circulation via the lymphatic pathway, not via portal circulation in adult rats.

Animals↗

PubMed2004

Lactoferrin enhances peripheral opioid-mediated antinociception via nitric oxide in rats.

Lactoferrin (LF) is a multifunctional protein found in various biological fluids. However, the peripheral action of lactoferrin remains unknown. In this study, peripherally applied bovine lactoferrin showed antinociceptive effect that was reversed by a mu-opioid receptor antagonist, D-Phe-Cys-Tyr-D-Trp-Orn-Thr-NH(2) (CTOP), or by a nitric oxide synthase (NOS) inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME), but not by an inactive enantiomer of L-NAME, N(G)-nitro-D-arginine methyl ester (D-NAME), during phase 1 and phase 2 in the rat formalin test. Peripheral coadministration of a micro-opioid receptor agonist, morphine, with subeffective dose of bovine lactoferrin produced a potentiated antinociceptive effect compared to that of morphine alone during both phases in the formalin test. This potentiated antinociception by morphine with bovine lactoferrin was reversed by CTOP or by L-NAME. These results suggest that bovine lactoferrin exerts an antinociceptive activity via potentiation of the peripheral micro-opioidergic system, and that nitric oxide (NO) is involved in this potentiation.

Analgesics↗

PubMed2004

Bovine lactoferrin reduces plasma triacylglycerol and NEFA accompanied by decreased hepatic cholesterol and triacylglycerol contents in rodents.

In the present study we examined whether oral administration of bovine lactoferrin (bLF) reduces plasma or hepatic triacylglycerol and cholesterol in mice. When bLF mixed with a standard commercial diet (10 g/kg) was given to mice for 4 weeks, plasma triacylglycerol and NEFA decreased, while plasma HDL-cholesterol levels increased (P<0.01). These changes in plasma lipid profiles were accompanied by significant decreases in hepatic cholesterol and triacylglycerol contents. When mice were fed a high-fat diet containing 300.0 g lard, 10.0 g cholesterol and 2.5 g bovine bile powder/kg for 4 weeks, bovine LF did not have any significant effects on plasma or hepatic cholesterol and triacylglycerol concentrations. Furthermore, bLF had no significant effects on faecal excretion of total bile acids in mice. Interestingly, bLF showed a suppressive effect on the lymphatic triacylglycerol absorption in chronically treated rats. We conclude that bLF has a beneficial effect on plasma cholesterol levels and retards hepatic lipid accumulation in mice fed a standard diet.

Animals↗

PubMed2004

Oral administration of lactoferrin inhibits inflammation and nociception in rat adjuvant-induced arthritis.

Lactoferrin (LF) is a ubiquitous protein which exists in milk, plasma, synovial fluids, cerebrospinal fluid and other biological fluids. LF is also well known as a natural immunomodulator. Recently, we found that bovine milk-derived LF (BLF) produced micro-opioid receptor-mediated analgesia. In this study, we examined whether oral administration of BLF causes anti-nociceptive and anti-inflammatory effects, and also whether it modulates LPS-induced TNF-alpha and IL-10 production in rat model of rheumatoid arthritis (RA), rat adjuvant arthritis. BLF was administrated once daily, starting 3 hr before (preventive experiment) or 19 days after (therapeutic experiment) adjuvant injection. In both experiments, BLF suppressed the development of arthritis and the hyperalgesia in the adjuvant-injected paw. The single-administered BLF produced a dose-dependent analgesia, which was reversed by naloxone, in the adjuvant arthritis rats. Both repeated and single administration of BLF suppressed TNF-alpha production and increased IL-10 production in the LPS-stimulated adjuvant arthritis rats. These results suggest that orally administered BLF has both preventive and therapeutic effects on the development of adjuvant-induced inflammation and pain. Moreover, the immunomodulatory properties of BLF, such as down-regulation of TNF-alpha and up-regulation of IL-10, could be beneficial in the treatment of RA. Thus, we concluded that LF can be safely used as a natural drug for RA patients suffering from joint pain.

Administration, Oral↗

PubMed2004

Cellular kinetics of villous epithelial cells and m cells in rabbit small intestine.

The cellular kinetics of villous columnar epithelial cells and M cells in the rabbit small intestine were determined by the use of 5-bromo-2'-deoxyuridine (BrdU) as a tracer. To identify M cells, vimentin antibody was used. The BrdU-labeled nuclei of columnar epithelial cells reached the base of intestinal villi in all portions at 1 day after BrdU administration. Thereafter, BrdU-labeled cells migrated toward the villous tip, but they did not move at a uniform speed. The epithelial cells which existed in intestinal villi on circular folds moved faster than those on mucosa other than circular folds. At 7 days after BrdU administration, the leading edge of BrdU-labeled epithelial cells already disappeared from the villous tip in all portions of the small intestine. In the ileal Peyer's patch, the BrdU-labeled nuclei of microvillous epithelial cells and vimentin-positive M cells appeared near the intestinal crypt orifice at 1 day after BrdU administration, and then migrated toward the luminal surface of the follicle-associated epithelium (FAE). As they moved toward the upper portion of FAE, the number of BrdU-labeled M cells on the side of the dome decreased simultaneously. The leading edge of BrdU-labeled epithelial cells disappeared from the top of the FAE within 7 days. These results suggest that M cells may differentiate from the undifferentiated cells in intestinal crypts within 1 day and disappear from the top of the FAE after the change of their form from M cells into microvillous epithelial cells.

Animals↗

PubMed2004

Distribution of the pores of epithelial basement membrane in the rat small intestine.

The distribution and diameter of the pores of epithelial basement membrane in the intestinal villi and the lymph nodules of ileal Peyer's patches were investigated in the rat small intestine by scanning electron microscopy after the removal of the overlying epithelial cells with OsO(4) maceration. In the duodenum, jejunum and ileum, the pores were mainly distributed at the upper three fourths of the villi, but were scarce around the top of the villi. The diameter of some of the pores in the upper three fourths of the villi was larger than that of those in the lower portion. The protrusion of lymphocytes and the cytoplasmic processes of macrophages were also seen at the orifices of the pores. In ileal Peyer's patches, in contrast, pores were densely distributed in the lower one third of the follicle-associated epithelium (FAE) where M cells were mainly seen. Furthermore, these pores were larger than those found in the upper two thirds. Lymphocytes or cytoplasmic processes of macrophages were frequently seen in the lower one third of FAE. These results suggest that the pores at the basement membrane correspond to the passage of the immunocompetent cells which are in contact with M cells or villous columnar epithelial cells and that the abundance of pores is a sign of aggressive interaction between the particular epithelial cells and the immunocompetent cells at the upper three fourths of intestinal villi and the lower one third of FAE in the rat small intestine.

Animals↗

PubMed2003

Suppression by p38 MAP kinase inhibitors (pyridinyl imidazole compounds) of Ah receptor target gene activation by 2,3,7,8-tetrachlorodibenzo-p-dioxin and the possible mechanism.

Cytochrome P-450 1A1 (CYP1A1) is known to be induced by aromatic hydrocarbons, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), through activation of the aryl hydrocarbon receptor (AhR). We found that p38 MAP kinase inhibitors (SB203580 and SB202190; 40 microm each; pyridinyl imidazole compounds) suppressed CYP1A1-mRNA induction by TCDD (2 nm) in mouse hepatoma Hepa-1 cells and in human hepatoma HepG2 cells, and also suppressed CYP1B1-mRNA induction by TCDD (2 nm) in human breast adenocarcinoma MCF7 cells. An analogue compound, SB202474, which does not inhibit p38 MAP kinase, also suppressed CYP1A1-mRNA induction by TCDD. Moreover, overexpression of a dominant-negative gene for p38 MAP kinase in Hepa-1 cells did not suppress Cyp1a1 reporter gene induction by TCDD. Therefore, the suppression of Cyp1a1 transcription by pyridinyl imidazole compounds is not because of their inhibition of p38 MAP kinase activity. Because SB203580 did not inhibit in vitro AhR transformation by TCDD, this compound was not acting as a simple AhR antagonist. SB203580 decreased TCDD-induced histone acetylation levels in the region of the Cyp1a1 gene promoter, especially around the TATA box sequence. This result suggests the possibility that pyridinyl imidazole compounds suppress the recruitment of some co-activator that has the histone acetyltransferase activity necessary for CYP1A1-mRNA transcription.

Animals↗

PubMed2003

Bovine lactoferrin has a nitric oxide-dependent hypotensive effect in rats.

Lactoferrin (LF) is a multifunctional protein that is found in milk, neutrophils, and other biological fluids. Under inflammatory conditions, LF production is increased in the periphery by neutrophils. However, the cardiovascular function of LF is still unknown. In the present study, we investigated the effect of bovine LF (BLF) on the mean blood pressure (MBP) and heart rate (HR) in urethane-anesthetized rats and the vascular function of BLF in the rat thoracic aorta. Intravenous injection of BLF produced dose-dependent decreases in MBP but did not affect HR, while the opioid agonist morphine decreased both MBP and HR. The hypotensive effect of BLF was not altered by naloxone methiodide, which cannot pass through the blood-brain barrier, but was significantly reduced by naloxone hydrochloride, which does pass through the blood-brain barrier. BLF-induced hypotension was completely blocked by the NO synthase inhibitor NG-nitro-l-arginine methyl ester (l-NAME) but not by the inactive enantiomer of l-NAME, NG-nitro-d-arginine methyl ester (d-NAME). BLF-induced hypotension was not altered by the muscarinic ACh receptor antagonist atropine or the cyclooxygenase inhibitor diclofenac. BLF produced relaxation in endothelium-intact but not endothelium-denuded aortic rings precontracted with phenylephrine. The relaxation evoked by BLF was completely blocked by l-NAME but not by d-NAME or the ATP-sensitive potassium channel blocker glibenclamide. These results suggest that BLF causes hypotension via an endothelium-dependent vasodilation that is strongly mediated by NO production and that BLF-induced hypotension also may be mediated by the central opioidergic system.

Adenosine Triphosphate↗

PubMed2003

Water retention in the acute phase of Kawasaki disease: relationship between oedema and the development of coronary arterial lesions.

UNLABELLED: Despite intravenous immunoglobulin therapy, a certain percentage of patients with Kawasaki disease (KD) still develop coronary arterial lesions (CAL). In an effort to find new combined therapies to reduce the incidence of CAL, we focused on the oedema which can be an important sign of the increased vascular permeability in KD. A total of 127 patients with KD were included in the retrospective study. Serial weekly changes in serum sodium and albumin levels from the 1st to the 4th week of illness were examined. In addition, the maximum rate of increase in body weight from admission to the 14th day of illness was evaluated. Serum sodium levels (mEq/l) in only the 2nd week of illness were significantly lower in patients with CAL than in those without CAL (mean +/- SD, 135.5+/-4.5 versus 138.0+/-2.4, P<0.05). Serum albumin levels in all 4 weeks were significantly lower in patients with CAL than in those without CAL ( P<0.001). The maximum rate (%) of increase in body weight from admission to the 14th day of illness was significantly higher in patients with CAL than in those without CAL (ranges and median values, 0-12.3 (7.0) versus 0-10.3 (3.2), P<0.001). CONCLUSION: these results suggest that water retention in the acute phase of Kawasaki disease may be a risk factor for CAL, and water intake of both infusion and oral intake should be kept to a minimum in order to avoid progressive oedema.

Acute Disease↗

PubMed2003

Conversion of sub-megasized DNA to desired structures using a novel Bacillus subtilis genome vector.

A novel genome vector using the 4215 kb Bacillus subtilis genome provides for precise target cloning and processing of the cloned DNA to the desired structure. Each process highly dependent on homologous recombination in the host B.subtilis is distinguished from the other cloning systems. A 120 kb mouse jumonji (jmj) genomic gene was processed in the genome vector to give a series of truncated sub-megasized DNA. One of these truncated segments containing the first intron was copied in a plasmid by a recombinational transfer method developed for B.subtilis. DNA manipulation previously considered difficult is argued with respect to DNA size and accuracy.

Animals↗

PubMed2003

Opioid mediated suppressive effect of milk-derived lactoferrin on distress induced by maternal separation in rat pups.

The present study assessed the effects of bovine milk-derived lactoferrin (bLf) on distress activities induced by maternal separation in 5- to 18-day-old rat pups. The rat pups were injected with BSA (100 mg/kg, i.p.; control) or bLf (100 mg/kg, i.p.) 30 min before the behavioral test. Distress activity was estimated by means of recording body movements or ultrasonic vocalizations (USVs). After 5 min of maternal separation, bLf significantly (P<0.01) suppressed body movements, particularly in the 10-day-old pups. This suppressive effect of bLf was reversed by pretreatment with naloxone, CTOP, and norBNI at doses of 0.1-1 mg/kg. Additionally, USVs were also suppressed by bLf, which was reversed by pretreatment with naloxone. Inhibition of nitric oxide synthase (NOS) with nitro-L-arginine methyl ester (L-NAME) dose dependently (3-10 mg/kg) suppressed separation-induced USV production in 10-day-old pups. Interestingly, the suppressive effect of bLf was completely reversed by pretreatment with a low dose (1 mg/kg) of L-NAME, which did not affect the USVs with single application. These findings demonstrate that milk-derived bLf suppresses distress induced by maternal separation via an opioid-mediated mechanism. Furthermore, bLf possibly activates NOS, and an elevated nitric oxide may cause some modification of the opioid system.

Animals↗

PubMed2003

Role of nerve growth factor in the regulation of parotid cell differentiation induced by rat serum.

The present study was undertaken to examine the factors that regulate rat serum (RS)- and nerve growth factor (NGF)-induced differentiation in a rat parotid acinar cell line. RS elicited extracellular signal-regulated kinase (ERK1/ERK2) activation within 5min, while cyclic AMP (cAMP) levels transiently rose after 6hr. RS also elicited a rise in amylase mRNA levels within 30min, which preceded the rise in amylase protein levels. A possible role for NGF was suggested by the findings that parotid cells express both TrkA and p75 receptors. The immunoreactivity of these NGF receptors was reduced during exposure to RS. Following prolonged incubation in RS when ERK activity subsided to near basal levels, NGF restored ERK1/ERK2 activity to the elevated level initially observed in RS. NGF was ineffective when cells were incubated in fetal bovine serum. NGF, when incubated in combination with the cAMP-generating neuropeptides, calcitonin gene-related peptide and vasoactive intestinal peptide, markedly enhanced the cellular amylase content produced by RS. We conclude that parotid cell differentiation arises from an activation of cell surface receptors by humoral factors in combination with NGF and cAMP-generating neuropeptides.

Amylases↗

PubMed2003

Lactoferrin enhances opioid-mediated analgesia via nitric oxide in the rat spinal cord.

Lactoferrin (LF) is a multifunctional protein that is found in milk, neutrophils, and other biological fluids, and its receptors have also been identified in the central nervous system. Recently, we found that bovine milk-derived LF (BLF) produced analgesia via a mu-opioid receptor-mediated response in the spinal cord. However, the precise mechanism of this analgesic effect remains unclear. In this study, spinally applied BLF produced analgesia that was reversed by coadministration with a nitric oxide (NO) synthase inhibitor, NG-nitro-l-arginine methyl ester, during phases 1 and 2 in the formalin test. Spinal coadministration of a mu-opioid receptor agonist, morphine, with a subeffective dose of BLF produced a much more highly potentiated analgesia than that produced by morphine alone during phases 1 and 2 in the formalin test. This potentiated analgesia by morphine with BLF was reversed by a mu-opioid receptor antagonist, d-Phe-Cys-Tyr-d-Trp-Orn-Thr-NH2, or by NG-nitro-l-arginine methyl ester. In the tail-flick test, continuous spinal infusion of morphine via an osmotic minipump over 6 days resulted in development of tolerance by day 4, but no tolerance of BLF was observed throughout the experiment. These results suggest that BLF acts as an enhancer of the spinal opioidergic system via an NO-mediated mechanism.

Analgesics↗

PubMed2003

Novel function of bovine milk-derived lactoferrin on antinociception mediated by mu-opioid receptor in the rat spinal cord.

Lactoferrin (LF) is a multifunctional protein that is found in milk, neutrophils, and other biological fluids. Although LF and the LF receptor have been identified in the central nervous system (CNS), the physiological role of LF remains unknown. We found that bovine milk-derived LF (BLF) reduces nociception in various pain models, as shown by the formalin test, hot plate test, and acetic acid writhing test in rats. Intraperitoneal (i.p.) administration of BLF significantly inhibited nociception in these pain models. These antinociceptive effects were also confirmed in BLF-fed rats. The antinociceptive effects of BLF were blocked by naloxone treatment, even though prostaglandin E(2) (PGE(2)) production in the ascites fluid that accumulated during the writhing test was not affected by BLF. Intrathecal (i.t.) application of BLF caused marked antinociceptive effects that were reversed by co-administration of a specific mu-opioid receptor antagonist, D-Phe-Cys-Tyr-D-Trp-Orn-Thr-NH(2) (CTOP), or by naloxone during the formalin test. We conclude that LF possesses mu-opioid receptor-mediated antinociceptive activity in the spinal cord.

Analgesics↗

PubMed2003

Possible regulatory mechanism of DHA-induced anti-stress reaction in rats.

To determine whether docosahexaenoic acid (DHA) affects stress responses in rats, we investigated its influence on several behavioral tests. Female rats were fed a diet deficient in (n-3) fatty acid from mating through pregnancy and lactation. Male pups fed the same diet as their dams were used for experiments. The effects of dietary (n-3) fatty acid deficiency and supplementation with DHA on psychological stress and conditioned-fear stress were investigated. The effect of DHA on psychological stress was examined by an elevated plus-maze test. The (n-3) deficient rats spent significantly (P<0.05) less time in the open arms; after 1 week of supplementation with DHA, they showed a significant (P<0.01) improvement. We then examined the paired effects of DHA and CRH on stress manifestations by an intracerebroventricular (i.c.v.) cannulation and behavior testing. An i.c.v. infusion of CRH (500 pmol) under resting conditions was shown to have stress-inducing effects on behavior such as decreases of rearing, smelling and feeding, and increases of face washing; the supplementation of DHA significantly improved these distress behaviors. Finally, conditioned fear was induced by 40 min forced exposure to a cage in which the rat had experienced footshocks (30 x 1 mA x 1 s) 1 day before. Freezing behavior was dramatically suppressed by the supplementation of DHA, even 48 h after the conditioning treatment. Furthermore, the effect of DHA on the conditioned fear stress response is maintained over a long-term period. The i.c.v. pre-treatment of rats with bicuculline, a GABA(A) receptor antagonist, enhanced the conditioned-fear-induced freezing time in a dose-dependent fashion in the (n-3) fatty acid deficient animals. Significantly, the DHA supplemented group was not affected by the pre-treatment with bicuculline. From these findings, it is concluded that the involvement of DHA in stress responses may act via a GABA(A) receptor-mediated mechanism.

Animals↗