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Biomedical subjects

H Emoto

Publications and source records attributed to H Emoto.

At least 19 recordsLinked to original sources
PubMed2000

Noradrenaline systems in the hypothalamus, amygdala and locus coeruleus are involved in the provocation of anxiety: basic studies.

A variety of stressful events, including emotional stress, cause a marked increase in noradrenaline release in several brain regions, and especially in the hypothalamus, amygdala and locus coeruleus, in the rat brain. These findings suggest that an increased noradrenaline release could be closely related to the provocation of negative emotions such as anxiety and/or fear. In order to confirm this hypothesis, we carried out several studies. Diazepam, a typical benzodiazepine anxiolytic, significantly attenuated not only the immobilization stress-induced increase in noradrenaline release in the three rat brain regions but also the emotional changes of these animals, and these effects were antagonized by flumazenil, a benzodiazepine antagonist. Naloxone and opioid agents, such as morphine, beta-endorphin and [Met(5)]-enkephalin, significantly enhanced and attenuated the stress-induced increase in noradrenaline release in these regions and the stress-induced emotional change, respectively. Two stressful events which predominantly involve emotional factors, i.e., psychological stress and conditioned fear, caused significant increases in noradrenaline release selectively in these three brain regions and these increases were also significantly attenuated by pretreatment with diazepam in a flumazenil reversible manner. Yohimbine, an alpha(2)-adrenoceptor antagonist which caused a marked increase in noradrenaline release in the several brain regions, had an anxiolytic action in the two behavioral tests involving anxiety, i.e., the conditioned defensive burying test and the modified forced swim test. beta-Carbolines, which possess anxiogenic properties, significantly increased noradrenaline release in the hypothalamus, amygdala and locus coeruleus. Taken together, these findings suggest that the increased release of noradrenaline in the hypothalamus, amygdala and locus coeruleus is, in part, involved in the provocation of anxiety and/or fear in animals exposed to stress, and that the attenuation of this increase by benzodiazepine anxiolytics acting via the benzodiazepine receptor/GABAA receptor/chloride ionophore supramolecular complex may be the basic mechanism of action of these anxiolytic drugs.

Amygdala↗
PubMed2000

Effects of acute and chronic administration of MCI-225, a new selective noradrenaline reuptake inhibitor with 5-HT3 receptor blocking action, on extracellular noradrenaline levels in the hypothalamus of stressed rats.

In the present study, we investigated the effects of acute and chronic systemic administration of MCI-225 (4-(2-fluorophenyl)-6-methyl-2-(1-piperazinyl)thieno[2,3-d]pyrimidine monohydrate hydrochloride), a newly-developed selective noradrenaline (NA) reuptake inhibitor with 5-HT3-receptor-blocking action, on extracellular NA levels in the hypothalamus of stressed and non-stressed rats by utilizing intracerebral microdialysis. Acute administration of MCI-225 (3 and 10 mg/kg, p.o.) significantly and dose-dependently increased extracellular NA levels in the hypothalamus in non-stressed rats. Footshock for 20 min also significantly increased NA levels in the hypothalamus of both groups of rats pretreated with vehicle and MCI-225. Although chronic administration of MCI-225 (3 or 10 mg/kg, p.o. for 14 days) did not alter the basal extracellular NA levels in the hypothalamus, the stress-induced increases in extracellular NA levels were significantly lower in rats chronically treated with MCI-225 (10 mg/kg) than those of rats pretreated with vehicle for the same period. The increase in extracellular NA levels induced by MCI-225 challenge (3 or 10 mg/kg, p.o.) were not different between rats chronically treated with MCI-225 or vehicle. These results suggest that MCI-225 enhances extracellular NA levels in the hypothalamus in both non-stressed and stressed rats by inhibiting NA uptake and that chronic systemic administration of MCI-225 did not alter basal extracellular NA levels, but reduced the increase in NA release caused by footshock stress. These data suggest the possibility that MCI-225 might possess anxiolytic and/or antidepressant properties.

Adrenergic Uptake Inhibitors↗
PubMed1999

Psychological stress selectively increases extracellular dopamine in the 'shell', but not in the 'core' of the rat nucleus accumbens: a novel dual-needle probe simultaneous microdialysis study.

In order to compare psychological stress-induced dopamine (DA) release in two subterritories (e.g. shell and core) of the nucleus accumbens of the same animal, a novel dual-needle microdialysis probe has been developed. The two needles were placed in the ipsilateral shell and core subterritories of the nucleus accumbens under pentobarbital anesthesia and 24 h later the microdialysis was started. Basal DA output was not significantly different between the shell and the core. Psychological stress for 20 min significantly increased extracellular DA levels in the shell of the nucleus accumbens, however, the levels of dopamine remained almost unaltered in the core. This finding suggests that DA transmission in the shell of the nucleus accumbens was selectively activated during psychological stress, and that the shell plays an important role in emotional responses. The results further show that microdialysis using the novel dual-needle probe could be very useful to differentiate neurochemical changes occurring in neighboring areas in the brain.

Animals↗
PubMed1999

FGF-10 is a growth factor for preadipocytes in white adipose tissue.

FGF-10 is a mesenchymal factor affecting epithelial cells during pattern formation. However, the expression and physiological role of FGF-10 in adults remains to be elucidated. We examined the expression of FGF-10 mRNA in a variety of adult rat tissues, and found to be most abundant in white adipose tissue. In white adipose tissue, FGF-10 mRNA was expressed in preadipocytes but not in mature adipocytes. The expression in white adipose tissue during postnatal development was also examined. The expression level was low at postnatal day 10 (P10). However, FGF-10 mRNA was abundantly detected later on (P28 and P48) when white adipose tissue growth was stimulated. We also examined the activity of recombinant FGF-10 for primary rat preadipocytes. FGF-10 showed significant mitogenic activity for primary preadipocytes, but did not affect the differentiation of preadipocytes. The expression profile of FGF-10 mRNA and the activity of FGF-10 reported here indicate that FGF-10, a unique secreted factor produced in white adipose tissue, acts as a growth factor for preadipocytes in white adipose tissues.

Adipocytes↗
PubMed1998

NMDA- and MK801-induced changes in dopamine release are attenuated in kainic acid-lesioned nucleus accumbens of conscious rats: an in vivo microdialysis study.

Local application of N-methyl-d-aspartate (NMDA) and a NMDA receptor antagonist, MK801 through the dialysis membrane into the nucleus accumbens (NAC) caused a significant decrease and increase in extracellular dopamine (DA) in the NAC of conscious rats, respectively. These neurochemical changes were significantly smaller in the kainic acid (KA)-lesioned NAC than in the intact NAC. These findings show that locally applied NMDA and MK801 into the NAC modulate DA release mainly through indirect mechanism involving putative GABA neuron of the NAC.

Animals↗
PubMed1998

[Clinical advantages and myocardial protection of normothermal CPB--comparison with hypothermal CPB].

We studied the clinical advantages and myocardial protection of normothermal CPB with comparing to hypothermal CPB. 22-cases of adult CABG were classified under two groups, according to the temperature of CPB. (Normothermal group: 37 degrees C, Hypothermal group: 32 degrees C) In both groups, the assistant CPB time after aortic declamp, the use of cardioversion that meaned the spontaneous recovery to sinus rhythm appeared or not, the dose of cathecholamines in- and post-operation, and the amounts of postoperative bleeding (after 6 h and 12 h) were compared as the clinical results and the data of CPK-MB, Myocin LC-II, and Troponin-T were measured as the effects of myocardial protection. The method of myocardial protection was the intermittent antegrade cold blood cardioplegia with terminal warm blood for all cases. As a result, the assistant CPB time after aortic declamp, the use of cardiovasion, and the amounts of postoperative bleeding (both of 6 h and 12 h) were less in normothermal group rather than in hypothermal group. (p < 0.05). However we had no differences about the dose of cathecholamines in post-operation and the data of three items between two groups. So, it suggests that the sufficient effects of myocardial protection could be obtained in normothermal CPB as in hypothermal CPB. Therefore we conclude that normothermal CPB could provide some clinical advantages, such as shortening CPB time, recovery of sinus rhythm, and prevention of postoperative bleeding, compared to hypothermal CPB and sufficient myocardial protection.

Blood Loss, Surgical↗
PubMed1997

Recovery from activity-stress ulcer by ad lib feeding in rats.

In order to investigate the recovery from activity-stress ulcers by ad lib-feeding and/or cessation of running, male Wistar rats were exposed to the activity-stress paradigm, and the rats that revealed hypothermia (their rectal temperature fell below 36 degrees C) were sacrificed either immediately or after several 24 h periods of healing. Rats that were sacrificed immediately after the appearance of hypothermia and those that were exposed to restricted feeding plus cessation of running revealed severe activity-stress ulcers, whereas few ulcers were observed in rats given ad lib-feeding and those that were given ad lib-feeding plus cessation of running. Although no significant differences in relative weights of spleen and thymus were obtained among the different recovery conditions, the relative weights of the adrenal glands were highest in the restricted feeding plus cessation of running group, whereas, the other animals exposed to the activity-stress paradigm showed no differences. These results indicate that activity-stress ulcers recover under conditions of ad lib-feeding within 24 h, but they are not influenced by cessation of running. These data also suggest that organ weights are not affected by any manipulations employed in the present study.

Animals↗
PubMed1997

Structure and expression of human fibroblast growth factor-10.

We isolated the cDNA encoding a novel member of the human fibroblast growth factor (FGF) family from the lung. The cDNA encodes a protein of 208 amino acids with high sequence homology (95.6%) to rat FGF-10, indicating that the protein is human FGF-10. Human FGF-10 as well as rat FGF-10 has a hydrophobic amino terminus ( approximately 40 amino acids), which may serve as a signal sequence. The apparent evolutionary relationships of human FGFs indicate that FGF-10 is closest to FGF-7. Chromosomal localization of the human FGF-10 gene was examined by in situ hybridization. The gene was found to map to the 5p12-p13 region. Human FGF-10 (amino acids 40 to 208 with a methionine residue at the amino terminus) was produced in Escherichia coli and purified from the cell lysate. Recombinant human FGF-10 (approximately 19 kDa) showed mitogenic activity for fetal rat keratinizing epidermal cells, but essentially no activity for NIH/3T3 cells, fibroblasts. The specificity of mitogenic activity of FGF-10 is similar to that of FGF-7 but distinct from that of bFGF. In structure and biological activity, FGF-10 is similar to FGF-7.

Amino Acid Sequence↗
PubMed1997

Fibroblast growth factor 10 (FGF10) and branching morphogenesis in the embryonic mouse lung.

During mouse lung morphogenesis, the distal mesenchyme regulates the growth and branching of adjacent endoderm. We report here that fibroblast growth factor 10 (Fgf10) is expressed dynamically in the mesenchyme adjacent to the distal buds from the earliest stages of lung development. The temporal and spatial pattern of gene expression suggests that Fgf10 plays a role in directional outgrowth and possibly induction of epithelial buds, and that positive and negative regulators of Fgf10 are produced by the endoderm. In transgenic lungs overexpressing Shh in the endoderm, Fgf10 transcription is reduced, suggesting that high levels of SHH downregulate Fgf10. Addition of FGF10 to embryonic day 11.5 lung tissue (endoderm plus mesenchyme) in Matrigel or collagen gel culture elicits a cyst-like expansion of the endoderm after 24 hours. In Matrigel, but not collagen, this is followed by extensive budding after 48-60 hours. This response involves an increase in the rate of endodermal cell proliferation. The activity of FGF1, FGF7 and FGF10 was also tested directly on isolated endoderm in Matrigel culture. Under these conditions, FGF1 elicits immediate endodermal budding, while FGF7 and FGF10 initially induce expansion of the endoderm. However, within 24 hours, samples treated with FGF10 give rise to multiple buds, while FGF7-treated endoderm never progresses to bud formation, at all concentrations of factor tested. Although exogenous FGF1, FGF7 and FGF10 have overlapping activities in vitro, their in vivo expression patterns are quite distinct in relation to early branching events. We conclude that, during early lung development, localized sources of FGF10 in the mesoderm regulate endoderm proliferation and bud outgrowth.

Animals↗
PubMed1996

[Successful direct embolectomy for acute massive pulmonary thromboembolism].

A 35-year-old woman was bedridden because of a fall and developed pulmonary embolism after venous thromboembolism of lower extremity. Although anticoagulation therapy was immediately carried out, hemodynamics deteriorated gradually into the state of class IV in Green-field's classification. As a result, an urgent surgical procedure was performed. Under moderate hypothermic cardio-pulmonary bypass, the aorta was cross-clamped and the pulmonary artery was opened. An 18 gram clot was taken out directly and other small pieces of clot were removed with a fiberscope, a Fogarty catheter and an aspirating tube. After surgery the patient recovered from symptoms efficiently. Some cases of acute pulmonary thromboembolism have been reported, however, the generalized classification and surgical indication for this disease have not been established yet. But, as all of reports mentions, surgical procedure is recommended positively to these cases that resist anticoagulation therapy.

Acute Disease↗
PubMed1994

Effect of opioid peptides on dopamine release from nucleus accumbens after repeated treatment with methamphetamine.

The effect of opioid peptides on extracellular dopamine levels in the nucleus accumbens was compared between rats treated with methamphetamine and saline repeatedly (for 9 days) by using microdialysis. After the period of repeated treatment, the rats in both groups were kept for an additional 9 days without further treatment. Repeated administration of methamphetamine reduced the decreasing effect of dynorphin (10 microM), applied locally in the perfusate, and enhanced the increasing effect of [D-Ala2,MePhe4,Gly-ol5]enkephalin (DAGO, 10 microM) on the extracellular dopamine levels in the nucleus accumbens. It is possible that repeated treatment with methamphetamine leads to attenuation of the inhibition and enhancement of the stimulation of dopamine release from the nucleus accumbens via presynaptic dynorphin- and enkephalin-sensitive receptors, respectively.

Analgesics↗
PubMed1994

Opposite changes in the mesolimbic dopamine metabolism in the nerve terminal and cell body sites induced by locally infused baclofen in the rat.

Infusion of baclofen (10(-4) M, 1 h) into the ventral tegmental area (VTA), the cell body site of mesolimbic dopamine (DA) neuron system in conscious rats, caused a decrease in both axonal and somatodendritic DA release in this neuron system, when monitored by in vivo microdialysis using two probes simultaneously placed in both the NAC and the VTA. Levels of the metabolite of DA, 3,4-dihydroxyphenylacetic acid (DOPAC) in the VTA decreased significantly in a similar manner following infused baclofen into the VTA, however, a pronounced increase in DOPAC outflow was observed in dialysates from the NAC. This dissociated changes in DA metabolism observed in the NAC may possibly be derived from regulatory mechanisms via an autoreceptor located in the DA nerve terminals.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1993

Muscimol-induced increase in dopamine release and metabolism is not observed in kainic acid-lesioned striatum of conscious rats: an in vivo microdialysis study.

Local application of muscimol through the striatal dialysis membrane caused a significant increase in both dopamine release and dopamine metabolism in the striatum of conscious rats, however, both elevations induced by muscimol were significantly lower in the kainic acid-lesioned striatum when assessed with in vivo brain microdialysis. These findings show that intra-striatal muscimol indirectly stimulates nigrostriatal dopaminergic function by possibly causing an inhibition of striatal gamma-aminobutyric acid neurons.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1993

A CRF antagonist attenuates stress-induced increases in NA turnover in extended brain regions in rats.

We investigated the effects of intracerebroventricular (i.c.v.) administration of corticotropin-releasing factor (CRF) antagonist, alpha-helical CRF9-41 (ahCRF), on increases in noradrenaline (NA) turnover caused by immobilization stress in rat brain regions. Pretreatment with ahCRF (50 or 100 micrograms) significantly attenuated increases in levels of 3-methoxy-4-hydroxyphenylethyleneglycol sulfate (MHPG-SO4), the major metabolite of NA in rat brain, in the locus coeruleus (LC) region, and attenuated the MHPG-SO4/NA ratio after immobilization stress for 50 min in the cerebral cortex, hippocampus, amygdala, midbrain and hypothalamus. However, stress-induced increases in plasma corticosterone levels were not decreased significantly by pretreatment with ahCRF. These results suggest that CRF, released during stress, causes increases in NA release in extended brain regions of stressed rats.

Animals↗
PubMed1993

Facilitatory modulation of mesolimbic dopamine neuronal activity by a mu-opioid agonist and nicotine as examined with in vivo microdialysis.

Administration of either Tyr-D-Ala-Gly-MePhe-Gly(ol) (DAGO), a mu-opioid agonist, or nicotine into the VTA (A10) caused an increase in both dopamine (DA) and its metabolite levels in both the A10 region and DA nerve terminals in the nucleus accumbens of rats when assessed with dual probe brain dialysis. These findings show that DAGO and nicotine increase both axonal- and somatodendritic-DA release, as well as metabolic activity in mesolimbic DA neurons, possibly by inducing an increase in neuronal impulse flow.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1993

Corticotropin-releasing factor enhances noradrenaline release in the rat hypothalamus assessed by intracerebral microdialysis.

Corticotropin-releasing factor (CRF) at a dose of 3 micrograms administered intracerebroventricularly (i.c.v.) elicited increases in noradrenaline (NA) release, which was assessed by intracerebral microdialysis in the anterior hypothalamus of conscious rats. These increases persisted until 140 min after infusion of CRF. These results indicate that CRF enhances NA release in the hypothalamus, an effect which may underlie the 'stress-like' properties of CRF.

Animals↗
PubMed1993

Compliance effects on small diameter polyurethane graft patency.

Microporous compliance matched and noncompliant grafts were compared in a dog carotid artery interposition model. We fabricated 4 mm diameter sponge type polyurethane (Biomer) tubes 5 cm in length with a 0.5 mm wall thickness. The luminal surface was covered with a 50 microns coating of cross-linked gelatin. Compliance was measured in vitro and in vivo by volume and vessel diameter changes. Over a mean arterial pressure range of 55-155 mm Hg, the diameter changes of grafts and stump arteries were measured in situ using an ultrasonic Hokanson device. Compliance matched grafts were found to have the same in vitro compliance values as the natural canine carotid at a mean arterial pressure of 100 mm Hg. Compliance matched and noncompliant grafts had values of 10.3 +/- 1.3 and 0.9 +/- 0.1 x 10(-2) mm Hg, respectively. End to end arterial anastomoses were constructed between the graft and the host arteries. The use of synthetic grafts with matched compliance to the adjacent natural vessels has been advocated as the ideal solution to circumvent the problems of graft failure. These studies indicate that compliance values for compliance matched grafts decreased immediately after implantation (from 10.3 to 6.5 x 10(-2) %/mm Hg) and within 6 weeks decreased to 3.6 x 10(-2) %/mm Hg. The compliance values for noncompliant grafts remained constant throughout the test period. At autopsy all grafts showed a tightly adhered tissue capsule. The thickness of the anastomotic hyperplasia at the distal sites of compliance matched grafts was significantly different (P < .05) than that of the adjacent artery. The patency for compliant and noncompliant grafts was 64% and 50%, respectively. Evidence for polyurethane graft degradation was obtained by Fourier transform infrared spectroscopy and gel permeation chromatography analysis of patent explants. Compliance mismatch alone does not contribute to graft failure, however, material degradation, suture technique and/or capsule formation can play a contributory role although these were not tested directly.

Animals↗