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1.
J Pharmacol Sci ; 145(3): 253-261, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33602505

ABSTRACT

Facilitation of cardiac function in response to signals from the sympathetic nervous system is initiated by the phosphorylation of L-type voltage-dependent Ca2+ channels (VDCCs) by protein kinase A (PKA), which in turn is activated by ß-adrenoceptors. Among the five subunits (α1, ß, α2/δ, and γ) of VDCCs, the α1 subunit and the family of ß subunits are substrates for PKA-catalyzed phosphorylation; however, the subunit responsible for ß-adrenergic augmentation of Ca2+ channel function has yet to be specifically identified. Here we show that the VDCC ß2 subunit is required for PKA phosphorylation upon sympathetic acceleration. In mice with ß2 subunit-null mutations, cardiac muscle contraction in response to isoproterenol was reduced and there was no significant increase in Ca2+ channel currents upon PKA-dependent phosphorylation. These findings indicate that within the sympathetic nervous system the ß2 subunit of VDCCs is required for physiological PKA-dependent channel phosphorylation.


Subject(s)
Calcium Channels, L-Type/metabolism , Cyclic AMP-Dependent Protein Kinases/metabolism , Cyclic AMP-Dependent Protein Kinases/physiology , Receptors, Adrenergic, beta/physiology , Sympathetic Nervous System/metabolism , Sympathetic Nervous System/physiology , Animals , Catalysis , Cells, Cultured , Isoproterenol/pharmacology , Mice , Mutation , Myocardial Contraction/drug effects , Phosphorylation , Receptors, Adrenergic, beta/genetics
2.
Heart Vessels ; 34(8): 1325-1331, 2019 Aug.
Article in English | MEDLINE | ID: mdl-30923895

ABSTRACT

Pulmonary function and arterial stiffness correlate significantly, attributing to the chronic inflammation of atherosclerosis. However, through the pulmonary or systemic circulation, pulmonary and vascular functions associate hemodynamically with cardiac morphology and function. In the present study, we investigated arterial-cardiac-pulmonary interaction by examining how the pulmonary and vascular functions correlate with the heart. This study investigated 55 consecutive subjects not suffering from pulmonary, vascular and cardiac disease who underwent health screening test at our medical center. First, the presence of atherosclerotic disease (hypertension, dyslipidemia and diabetes) and smoking status of the patients were determined. Next, pulmonary function test, vascular function test including cardio-ankle vascular index, and echocardiography were performed. Then, we examined the correlation among the pulmonary, vascular and the heart. Our results revealed many correlations among these three factors. Especially left atrial dimension (LAD) and E/A ratio (E/A) were important cardiac factors associated with both pulmonary and vascular functions independently. Conventionally, inflammatory responses are known to involve in the correlation between pulmonary and vascular functions. Our study demonstrated that cardiac function and morphology were also involved in this correlation, signifying that LAD and E/A plays important roles in the arterial-cardiac-pulmonary interaction.


Subject(s)
Heart/physiology , Pulmonary Artery/physiology , Pulse Wave Analysis , Vascular Stiffness , Aged , Echocardiography , Female , Heart/diagnostic imaging , Humans , Linear Models , Male , Middle Aged , Pulmonary Artery/diagnostic imaging , Respiratory Function Tests , Risk Factors
3.
Cardiovasc Drugs Ther ; 28(1): 53-9, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24158248

ABSTRACT

PURPOSE: Eicosapentaenoic acid (EPA) has been reported to augment endothelial function and improve clinical outcomes in patients with coronary artery disease (CAD). The purpose of this study was to determine whether EPA could improve residual endothelial dysfunction despite adequate lipid-lowering with statin in CAD patients. METHODS: Eighty patients with established CAD, who had been on statin treatment and had serum low-density lipoprotein cholesterol (LDL-C) levels <100 mg/dl, were randomly assigned to receive either 1,800 mg of EPA daily plus statin (EPA group, n = 40) or statin alone (Control group, n = 40). Lipid profiles and flow-mediated dilation (FMD) were assessed just before and after more than 3 months of treatment in both groups. Only patients who had impaired FMD (<6 %) before randomization were enrolled. RESULTS: After treatment for 5.2 ± 1.7 months, the EPA group showed a significant increase in the serum concentration of EPA and EPA to arachidonic acid (AA) (EPA/AA) ratio (62.5 ± 38.1 to 159.8 ± 53.8 µg/ml, 0.45 ± 0.34 to 1.20 ± 0.55, p < 0.01 for both). In the EPA group, serum triglycerides significantly decreased (150.7 ± 92.9 to 119.3 ± 60.7 mg/dl, p = 0.02), whereas no significant change was seen in the Control group. FMD, the primary study endpoint, showed a significant improvement in the EPA group (2.6 ± 1.6 % to 3.2 ± 1.6%, p = 0.02), whereas no significant change was observed in the Control group (2.7 ± 1.6% to 2.4 ± 1.7 %, p = 0.29). CONCLUSIONS: EPA improved endothelial function and impaired FMD in patients with established CAD who were on optimal statin therapy.


Subject(s)
Coronary Artery Disease/drug therapy , Eicosapentaenoic Acid/therapeutic use , Endothelium, Vascular/drug effects , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Aged , Coronary Artery Disease/physiopathology , Drug Therapy, Combination , Eicosapentaenoic Acid/administration & dosage , Endothelium, Vascular/pathology , Humans , Hydroxymethylglutaryl-CoA Reductase Inhibitors/administration & dosage , Lipids/blood , Male , Middle Aged , Prospective Studies , Treatment Outcome
4.
Echocardiography ; 30(3): E67-9, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23305107

ABSTRACT

Aortopulmonary artery fistula is uncommon, but the clinical outcome is often lethal. A 76-year-old man with a history of acute thoracic aortic dissection 6 years previously was admitted with dyspnea. A chest x-ray showed pleural effusion and pulmonary congestion. Transthoracic echocardiography revealed preserved systolic function, but continuous and abnormal flow from the distal aortic arch into the pulmonary artery (PA). Transesophageal echocardiography (TEE) in the Doppler color-flow mode demonstrated a left-to-right shunt between a large distal aortic arch aneurysm and the left PA via an aortopulmonary fistula and a pressure gradient across the shunt of 56 mmHg. Contrast-enhanced computed tomography showed that the aneurysm compressed the PA. Aortography also revealed a large distal aortic arch aneurysm and almost simultaneous contrast enhancement of the aorta and the PA. Right-heart catheterization showed a significant increase in oxygen saturation between the right ventricle and the PA. A left-to-right shunt due to a distal aortic arch aneurysm rupturing into the left PA was diagnosed based on these findings. TEE was very helpful in confirming the presence and precise location of the fistula.


Subject(s)
Aortic Aneurysm, Thoracic/diagnostic imaging , Aortic Aneurysm, Thoracic/etiology , Aortic Rupture/diagnostic imaging , Aortic Rupture/etiology , Arterio-Arterial Fistula/complications , Arterio-Arterial Fistula/diagnostic imaging , Pulmonary Artery/diagnostic imaging , Aged , Diagnosis, Differential , Humans , Male , Pulmonary Artery/abnormalities , Ultrasonography
5.
Cureus ; 15(8): e43392, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37701010

ABSTRACT

OBJECTIVE: Factors such as age, vital signs, renal function, Killip class, cardiac arrest, elevated cardiac biomarker levels, and ST deviation predict survival in patients with acute myocardial infarction (AMI). However, the existing risk assessment tools lack comprehensive consideration of catheter-related factors, and short-term prognostic predictors are unknown. This study aimed to clarify in-hospital prognostic predictors in hospitalized patients with AMI. METHODS: Five hundred and thirty-six patients who underwent percutaneous coronary intervention (PCI) for AMI were divided into non-survivor (n = 36) and survivor (n = 500) groups. Coronary risk factors, laboratory findings, angiographic findings, and clinical courses were compared between the two groups. Multiple logistic regression was used to analyze in-hospital death in pre- and post-PCI phases. RESULTS: In the pre-PCI phase, multiple logistic regression analysis revealed several predictors of in-hospital death, including systolic blood pressure [odds ratio (OR) = 0.985, p = 0.023)], Killip class ≥2 (OR = 14.051, p <0.001), and chronic kidney disease (OR = 4.859, p = 0.040). In the post-PCI phase, multiple logistic regression analysis revealed additional predictors of in-hospital death, including Killip class ≥2 (OR = 5.982, p = 0.039), presence of lesions in the left main trunk (OR = 51.381, p = 0.044), utilization of intra-aortic balloon pumps and percutaneous cardiopulmonary support (OR = 6.141, p = 0.016), and presence of multi-vessel disease (OR = 6.323, p = 0.022). CONCLUSION: Predictors of in-hospital death in AMI extend beyond conventional risk factors to include culprit lesions, mechanical support, and multi-vessel disease that manifest post-PCI.

6.
Health Sci Rep ; 6(12): e1739, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38033711

ABSTRACT

Background and Aims: As the population of aging societies continues to grow, the prevalence of complex coronary artery diseases, including calcification, is expected to increase. Rotational atherectomy (RA) is an essential technique for treating calcified lesions. This study aimed to assess the usefulness of the drilling noise produced during rotablation as a parameter for evaluating the safety and effectiveness of the procedure. Methods: A human body model mimicking calcified stenotic coronary lesions was constructed using plastic resin, and burrs of sizes 1.25 and 1.5 mm were utilized. To identify the noise source during rotablation, we activated the ROTAPRO™ rotablator at a rotational speed of 180,000 rpm, recording the noise near the burr (inside the mock model) and advancer (outside). In addition to regular operation, we simulated two major complications: burr entrapment and guidewire transection. The drilling noise recorded in Waveform Audio File Format files was converted into spectrograms for analysis and an autoencoder analyzed the image data for anomalies. Results: The drilling noise from both inside and outside the mock model was predominantly within the 3000 Hz frequency domain. During standard operation, intermittent noise within this range was observed. However, during simulated complications, there were noticeable changes: a drop to 2000 Hz during burr entrapment and a distinct squealing noise during guidewire transection. The autoencoder effectively reduced the spectrogram data into a two-dimensional representation suitable for anomaly detection in potential clinical applications. Conclusion: By analyzing drilling noise, the evaluation of procedural safety and efficacy during RA can be enhanced.

7.
J Neurosci ; 31(47): 16916-27, 2011 Nov 23.
Article in English | MEDLINE | ID: mdl-22114262

ABSTRACT

In early postnatal development, perisomatic innervation of cerebellar Purkinje cells (PCs) switches from glutamatergic climbing fibers (CFs) to GABAergic basket cell fibers (BFs). Here we examined the switching process in C57BL/6 mice. At postnatal day 7 (P7), most perisomatic synapses were formed by CFs on to somatic spines. The density of CF-spine synapses peaked at P9, when pericellular nest around PCs by CFs was most developed, and CF-spine synapses constituted 88% of the total perisomatic synapses. Thereafter, CF-spine synapses dropped to 63% at P12, 6% at P15, and <1% at P20, whereas BF synapses increased reciprocally. During the switching period, a substantial number of BF synapses existed as BF-spine synapses (37% of the total perisomatic synapses at P15), and free spines surrounded by BFs or Bergmann glia also emerged. By P20, BF-spine synapses and free spines virtually disappeared, and BF-soma synapses became predominant (88%), thus attaining the adult pattern of perisomatic innervation. Parallel with the presynaptic switching, postsynaptic receptor phenotype also switched from glutamatergic to GABAergic. In the active switching period, particularly at P12, fragmental clusters of AMPA-type glutamate receptor were juxtaposed with those of GABA(A) receptor. When examined with serial ultrathin sections, immunogold labeling for glutamate and GABA(A) receptors was often clustered beneath single BF terminals. These results suggest that a considerable fraction of somatic spines is succeeded from CFs to BFs and Bergmann glia in the early postnatal period, and that the switching of postsynaptic receptor phenotypes mainly proceeds under the coverage of BF terminals.


Subject(s)
Nerve Fibers/physiology , Nerve Fibers/ultrastructure , Neurogenesis/physiology , Purkinje Cells/physiology , Purkinje Cells/ultrastructure , Animals , Animals, Newborn , Cerebellum/chemistry , Cerebellum/growth & development , Cerebellum/ultrastructure , Mice , Mice, Inbred C57BL , Nerve Fibers/chemistry , Purkinje Cells/chemistry , Synapses/chemistry , Synapses/physiology
8.
Int Arch Occup Environ Health ; 83(4): 455-66, 2010 Apr.
Article in English | MEDLINE | ID: mdl-19902235

ABSTRACT

OBJECTIVES: Literature survey has suggested that cadmium (Cd) in the general environment is more abundant in the northern part of the coast on the sea of Japan. The present survey was initiated to examine if the exposure to Cd in the area has been higher than other parts of Japan, and if so, the higher exposure has been associated with tubular dysfunction among the local residents. METHODS: In three prefectures of Akita, Yamagata and Ishikawa in the region, adult women (about 700 subjects per prefecture) were invited to participate in the survey. Each of the participants provided informed consents, offered spot urine samples and filled questionnaires (on age etc.). The urine samples were analyzed for Cd, alpha(1)-microglobulin (alpha(1)-MG), beta(2)-microglobulin (beta(2)-MG) and N-acetyl-beta-D: -glucosaminidase, together with creatinine and specific gravity. The results were combined with published data on two other prefectures of Niigata and Toyama (both in the area), as well as Japan as a whole (all Japan-A excluding Niigata prefecture, which was studied separately in the present study), and subjected to analysis for possible difference from all Japan-A in terms of the levels of internal Cd burden, and prevalence of beta(2)-MG-uria. RESULTS: Geometric means (GMs) for urinary Cd in the five prefectures were in a range from a low of 1.20 to a high of 2.65 microg/l, being higher than the GM (0.99 microg/l) for all Japan-A. GMs for alpha(1)-MG (2.15-2.80 mg/l) and beta(2)-MG (99-107 microg/l) were only slightly higher or even lower than all Japan-A values depending on the prefectures. Elevation in the prevalence of beta(2)-MG-uria was significant in Akita prefecture, but the elevation in beta(2)-MG was not associated with elevation in Cd in urine. Literature survey on general population Cd epidemiology showed that Cd, alpha(1)-MG and beta(2)-MG levels in urine of the residents in the five prefectures were within the levels reported for non-polluted areas, and such was also the case for prevalence of beta(2)-MG-uria. CONCLUSIONS: In an over-all evaluation, no clear-cut evidence was available for increased prevalence of Cd exposure-associated renal tubular dysfunction among general populations in the five prefectures in the northern part on the coast of Sea of Japan than in other prefectures in Japan, despite moderate elevation in urinary Cd levels.


Subject(s)
Cadmium/urine , Environmental Monitoring , Renal Insufficiency/urine , Acetylglucosaminidase/urine , Adult , Alpha-Globulins/urine , Biomarkers/urine , Cadmium/adverse effects , Creatinine/urine , Epidemiological Monitoring , Female , Humans , Japan/epidemiology , Middle Aged , Prevalence , Renal Insufficiency/chemically induced , Renal Insufficiency/epidemiology , Rivers/chemistry , beta 2-Microglobulin/urine
9.
Neurosci Res ; 57(2): 322-5, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17134779

ABSTRACT

Developmental shift in GABA actions from depolarization to hyperpolarization occurs as a result of decreasing the intracellular Cl(-) concentration regulated by K(+)-Cl(-) co-transporter 2 (KCC2). To clarify the time-course of the developmental shift on the Purkinje cells, we examined KCC2-localization in the embryonic mouse cerebellum. The KCC2 was first detected within the Purkinje cells in the Purkinje cell layer of the hemisphere at embryonic day 15 (E15) and the vermis at E17, but the ventricular and intermediate zones were negative. These results suggest that GABA might become inhibitory on the Purkinje cells after their settling in the Purkinje cell layer.


Subject(s)
Cerebellum/cytology , Gene Expression Regulation, Developmental/physiology , Purkinje Cells/metabolism , Symporters/metabolism , Age Factors , Animals , Embryo, Mammalian , Mice , Mice, Inbred C57BL , Microscopy, Immunoelectron/methods , Purkinje Cells/ultrastructure , Symporters/ultrastructure , K Cl- Cotransporters
10.
J Neurosci ; 24(1): 96-102, 2004 Jan 07.
Article in English | MEDLINE | ID: mdl-14715942

ABSTRACT

The axoglial paranodal junction is essential for the proper localization of ion channels around the node of Ranvier. The integrity of this junction is important for nerve conduction. Although recent studies have made significant progress in understanding the molecular composition of the paranodal junction, it is not known how these membrane components are distributed to the appropriate sites and interact with each other. Here we show that CD9, a member of the tetraspanin family, is present at the paranode. CD9 is concentrated in the paranode as myelination proceeds, but CD9 clusters become diffuse, associated with disruption of the paranode, in cerebroside sulfotransferase-deficient mice. Immunohistochemical and Western blot analysis showed that CD9 is distributed predominantly in the PNS. Ablation of CD9 in mutant mice disrupts junctional attachment at the paranode and alters the paranodal components contactin-associated protein (also known as Paranodin) and neurofascin 155, although the frequency of such abnormalities varies among individuals and individual axons even in the same mouse. Electron micrographs demonstrated that compact myelin sheaths were also affected in the PNS. Therefore, CD9 is a myelin protein important for the formation of paranodal junctions. CD9 also plays a role in the formation of compact myelin in the PNS.


Subject(s)
Antigens, CD/analysis , Antigens, CD/physiology , Membrane Glycoproteins/analysis , Membrane Glycoproteins/physiology , Ranvier's Nodes/chemistry , Ranvier's Nodes/ultrastructure , Animals , Antigens, CD/genetics , Membrane Glycoproteins/genetics , Mice , Mice, Knockout , Myelin Sheath/physiology , Myelin Sheath/ultrastructure , Peripheral Nervous System/chemistry , Peripheral Nervous System/cytology , Tetraspanin 29
11.
J Neurosci ; 22(19): 8487-503, 2002 Oct 01.
Article in English | MEDLINE | ID: mdl-12351723

ABSTRACT

Organized synapse formation on to Purkinje cell (PC) dendrites by parallel fibers (PFs) and climbing fibers (CFs) is crucial for cerebellar function. In PCs lacking glutamate receptor delta2 (GluRdelta2), PF synapses are reduced in number, numerous free spines emerge, and multiple CF innervation persists to adulthood. In the present study, we conducted anterograde and immunohistochemical labelings to investigate how CFs innervate PC dendrites under weakened synaptogenesis by PFs. In the GluRdelta2 knock-out mouse, CFs were distributed in the molecular layer more closely to the pial surface compared with the wild-type mouse. Serial electron microscopy demonstrated that CFs in the knock-out mouse innervated all spines protruding from proximal dendrites of PCs, as did those in the wild-type mouse. In the knock-out mouse, however, CF innervation extended distally to spiny branchlets, where nearly half of the spines were free of innervation in contrast to complete synapse formation by PFs in the wild-type mouse. Furthermore, from the end point of innervation, CFs aberrantly jumped to form ectopic synapses on adjacent spiny branchlets, whose proximal portions were often innervated by different CFs. Without GluRdelta2, CFs are thus able to expand their territory along and beyond dendritic trees of the target PC, resulting in persistent surplus CFs by innervating the distal dendritic segment. We conclude that GluRdelta2 is essential to restrict CF innervation to the proximal dendritic segment, by which territorized innervation by PFs and CFs is properly structured and the formation of excess CF wiring to adjacent PCs is suppressed.


Subject(s)
Biotin/analogs & derivatives , Cerebellum/pathology , Membrane Transport Proteins , Nerve Fibers/pathology , Nervous System Malformations/pathology , Neurons, Afferent/pathology , Purkinje Cells/pathology , Receptors, Glutamate/deficiency , Vesicular Transport Proteins , Animals , Carrier Proteins/biosynthesis , Cerebellum/metabolism , Dendrites/ultrastructure , Dextrans , Immunohistochemistry , Iontophoresis , Mice , Mice, Knockout , Nerve Fibers/ultrastructure , Neurons, Afferent/metabolism , Neurons, Afferent/ultrastructure , Olivary Nucleus/metabolism , Purkinje Cells/metabolism , Purkinje Cells/ultrastructure , Receptors, Glutamate/genetics , Receptors, Glutamate/metabolism , Synapses/pathology , Synapses/ultrastructure , Vesicular Glutamate Transport Protein 2
12.
Brain Res Dev Brain Res ; 158(1-2): 41-9, 2005 Aug 08.
Article in English | MEDLINE | ID: mdl-16024093

ABSTRACT

In the brain, gamma-amino butyric acid (GABA), released extrasynaptically and synaptically from GABAergic neurons, plays important roles in morphogenesis, expression of higher functions and so on. In the GABAergic transmission system, plasma membrane GABA transporters (GATs) mediate GABA-uptake from the synaptic cleft in the mature brain and are thought to mediate diacrine of cytosolic GABA in the immature brain. In the present study, we focused on two GATs (GAT-1 and GAT-3) in the mouse cerebellar cortex, which are widely localized in neural and glial cells. Firstly, we examined the localization of GATs in the dendrites and cell bodies of developing GABAergic neurons, where GABA is extrasynaptically distributed, to clarify the GABA-diacrine before synaptogenesis. Secondly, we examined the developmental changes in the localization of GATs to reveal the development of the GABA-uptake system. Neither transporter was detected within the dendrites and cell bodies of GABAergic neurons, including Purkinje, stellate, basket and Golgi cells, in the immature cerebellar cortex. GAT-1 was observed within the Golgi cell axon terminals after postnatal day 5 (P5) and presynaptic axons of stellate and basket cells after P7. GAT-3 was localized within the astrocyte processes, sealing the GABAergic synapses in the Purkinje cell and granular layers after P10. These results indicated that GABA-diacrine did not work in the mouse cerebellar cortex. The onset of GAT-1-expression was prior to that of GAT-3. GAT-1 started to be localized within the GABAergic axon terminals during synapse formation. GAT-3 started to be localized within astrocyte processes when they sealed the synapses.


Subject(s)
Cerebellar Cortex/metabolism , Gene Expression Regulation, Developmental/physiology , Membrane Transport Proteins/metabolism , Synapses/metabolism , gamma-Aminobutyric Acid/metabolism , Age Factors , Amino Acid Transport Systems/metabolism , Animals , Calbindins , Cerebellar Cortex/growth & development , Cerebellar Cortex/ultrastructure , Female , GABA Plasma Membrane Transport Proteins , Guinea Pigs , Immunohistochemistry/methods , Male , Membrane Transport Proteins/genetics , Mice , Mice, Inbred C57BL , Microscopy, Immunoelectron/methods , Models, Neurological , S100 Calcium Binding Protein G/metabolism , Synapses/ultrastructure , Vesicular Inhibitory Amino Acid Transport Proteins
13.
Neurosci Res ; 50(4): 447-58, 2004 Dec.
Article in English | MEDLINE | ID: mdl-15567482

ABSTRACT

In the adult brain, gamma-amino butyric acid (GABA) is synaptically released and mediates inhibitory transmission. Recent studies have revealed that GABA is a trophic factor for brain development. To reveal the distribution of GABA and its secretion mechanisms during brain development, we investigated the immunohistochemical localization of two molecules, GABA and vesicular GABA transporter (VGAT), which is a GABAergic vesicle protein, in the developing mouse cerebellum by means of newly developed antibodies. Furthermore, we tested the relationship between developmental changes in distribution of above two molecules in the presynapses and ontogeny of GABAergic synapses. GABAergic synapses were detected by immunohistochemistry for the GABA(A) receptor alpha1 subunit, which is an essential subunit for inhibitory synaptic transmission in the mature cerebellar cortex. Until postnatal day 7 (P7), GABA was localized throughout the GABAergic neurons, and VGAT accumulated at axon varicosities and growth cones, where the alpha1 subunit did not accumulate. After P10, both GABA and VGAT became confined to the terminal sites where the alpha1 subunit was localized. These results suggested that GABA was extrasynaptically released from axon varicosities and growth cones by vesicular secretion 'exocytosis' and from all parts of GABAergic neurons during the cerebellar development by non-vesicular secretion 'diacrine'.


Subject(s)
Cerebellum/growth & development , Cerebellum/metabolism , Extracellular Space/metabolism , Growth Cones/metabolism , Presynaptic Terminals/metabolism , gamma-Aminobutyric Acid/metabolism , Amino Acid Transport Systems/metabolism , Animals , Animals, Newborn , Cerebellum/ultrastructure , Exocytosis/physiology , Growth Cones/ultrastructure , Immunohistochemistry , Interneurons/metabolism , Interneurons/ultrastructure , Mice , Mice, Inbred C57BL , Microscopy, Electron, Scanning , Neural Inhibition/physiology , Presynaptic Terminals/ultrastructure , Protein Subunits/metabolism , Purkinje Cells/metabolism , Purkinje Cells/ultrastructure , Receptors, GABA-A/metabolism , Synaptic Membranes/metabolism , Synaptic Membranes/ultrastructure , Synaptic Transmission/physiology , Vesicular Inhibitory Amino Acid Transport Proteins
14.
Anat Sci Int ; 79(3): 124-36, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15453613

ABSTRACT

In the adult central nervous system (CNS), GABA is a predominant inhibitory neurotransmitter that regulates glutamatergic activity. Recent studies have revealed that GABA serves as an excitatory transmitter in the immature CNS and acts as a trophic factor for brain development. Furthermore, synaptic transmission by GABA is also involved in the expression of higher brain functions, such as memory, learning and anxiety. These results indicate that GABA plays various roles in the expression of brain functions and GABAergic roles change developmentally in accordance with alterations in GABAergic transmission and signaling. We have investigated morphologically the developmental changes in the GABAergic transmission system and the key factors important for the formation of GABAergic synapses and networks using the mouse cerebellum, which provides an ideal system for the investigation of brain development. Here, we focus on GABA and GABA(A) receptors in the developing cerebellum and address the processes of how GABA exerts its effect on developing neurons and the mechanisms underlying the formation of functional GABAergic synapses.


Subject(s)
Cerebellum/growth & development , Neural Inhibition/physiology , Neural Pathways/growth & development , Presynaptic Terminals/metabolism , Synaptic Transmission/physiology , gamma-Aminobutyric Acid/metabolism , Animals , Cell Differentiation/physiology , Cerebellum/cytology , Cerebellum/metabolism , Humans , Neural Pathways/cytology , Neural Pathways/metabolism , Presynaptic Terminals/ultrastructure , Receptors, GABA-A/metabolism
15.
Brain Res Dev Brain Res ; 150(2): 177-90, 2004 Jun 21.
Article in English | MEDLINE | ID: mdl-15158081

ABSTRACT

In the adult central nervous system (CNS), gamma-amino butyric acid (GABA) is a predominant inhibitory neurotransmitter, which regulates glutamatergic activity. Recent studies have revealed that GABA serves as an excitatory transmitter in the immature CNS, and is involved in brain morphogenesis. To elucidate how GABA exerts its effect on immature neurons and how GABAergic synapses are formed, we examined both development of pre- and post-synaptic elements of the GABAergic synapses formed between granule and Golgi cells in the mouse cerebellar granular layer. Immunohistochemistry for glutamic acid decarboxylase (GAD) demonstrated that GABA was localized throughout the Golgi cells before postnatal day 7 (P7), and became confined to the axon terminals during the second postnatal week. Electron microscopic analysis demonstrated that GABAergic synapses were clearly detected at P10. In situ hybridization and immunohistochemistry for the GABA(A) receptor alpha1 and alpha6 subunits, which are mainly involved in inhibitory synaptic transmission, demonstrated that both subunits appeared at P7. Distribution of both subunits expanded in the granular layer with special reference to the development of GABAergic synapses. Furthermore, the majority of the subunits accumulated adjacent to the GABAergic terminals. These results suggested that in the granular layer, GABA might be non-synaptically secreted from Golgi cell axons and dendrites during the first postnatal week. From the second postnatal week, GABA is synaptically released and begins to mediate inhibitory transmission. Furthermore, it was suggested that GABAergic innervation could initiate expression and trafficking of the GABA(A) receptors containing the alpha1 and alpha6 subunits.


Subject(s)
Cerebellum/cytology , Neurons/ultrastructure , Synapses/physiology , gamma-Aminobutyric Acid/metabolism , Animals , Animals, Newborn , Cerebellum/growth & development , Cerebellum/physiology , Glutamate Decarboxylase/metabolism , Immunohistochemistry/methods , In Situ Hybridization/methods , Mice , Mice, Inbred C57BL , Microscopy, Immunoelectron/methods , Neural Networks, Computer , RNA, Messenger/metabolism , Receptors, GABA-A/metabolism , Synapses/ultrastructure
16.
Brain Res Dev Brain Res ; 148(2): 169-77, 2004 Feb 20.
Article in English | MEDLINE | ID: mdl-14766194

ABSTRACT

In the adult mammalian brain, synaptic transmission mediated by gamma-amino butyric acid (GABA) plays a role in inhibition of excitatory synaptic transmission. During brain development, GABA is involved in brain morphogenesis. To clarify how GABA exerts its effect on immature neurons, we examined the expression of the GABAA receptor alpha2 and alpha3 subunits, which are abundantly expressed before alpha1 and alpha6 subunits appear, in the developing mouse cerebellum using in situ hybridization. Proliferating neuronal precursors in the ventricular zone and external granular layer expressed neither alpha2 nor alpha3 subunits. Hybridization signals for the alpha2 and alpha3 subunit mRNAs first appeared in the differentiating zone at embryonic day 13 (E13). The alpha2 subunit was detected in the migrating and differentiating granule cells and cerebellar nucleus neurons until postnatal day 14 (P14). Hybridization signals for the alpha3 subunit mRNA, on the other hand, were localized in the developing Purkinje cells and cerebellar nucleus neurons, and disappeared from Purkinje cells by the end of first postnatal week. Taken together, this indicated that the alpha2 and alpha3 subunits were abundantly expressed in distinct types of cerebellar neurons after completing cell proliferation while forming the neural network. These results suggest that GABA might extrasynaptically activate the GABAA receptors containing alpha2 and/or alpha3 subunits on the differentiating neurons before finishing the formation of synapses and networks, and could be involved in neuronal differentiation and maturation in the cerebellum.


Subject(s)
Cerebellum/cytology , Gene Expression Regulation, Developmental , Neurons/metabolism , Protein Subunits/metabolism , Receptors, GABA-A/metabolism , Animals , Cell Count , Cell Differentiation/physiology , Cerebellum/embryology , Embryo, Mammalian , In Situ Hybridization/methods , Mice , Mice, Inbred C57BL , Neurons/cytology , Protein Subunits/genetics , Receptors, GABA-A/genetics
17.
Brain Res Dev Brain Res ; 145(2): 197-211, 2003 Nov 12.
Article in English | MEDLINE | ID: mdl-14604760

ABSTRACT

Synaptic transmission mediated by gamma-amino butyric acid (GABA) plays an important role in inhibition of glutamatergic excitatory transmission and expression of higher brain functions, such as memory, learning and anxiety. To elucidate mechanisms underlying formation of the postsynaptic elements for GABAergic transmission, we employed the reeler mutant mice in this study. In the reeler cerebellum, abnormal cytoarchitecture and an aberrant environment affect the formation of neural networks and maturation of neurons. We examined the expression and localization of GABA(A) receptor alpha subunits in the reeler cerebellum and determined whether various abnormalities in the reeler mice affected formation of the postsynaptic elements. In situ hybridization analysis revealed that the specific expression of alpha subunit mRNAs in each neuronal type was preserved. Abnormal expression of alpha subunits was not detected, although GABAergic networks were altered and neuronal maturation was severely disturbed. Immunohistochemistry for the alpha1 and alpha6 subunits, which were expressed abundantly in the reeler cerebellum, revealed that both subunit proteins accumulated at positions adjacent to GABAergic terminals. These results, taken together, suggested that expression of the GABA(A) receptor subunits in postsynaptic neurons might be genetically determined, but trafficking and accumulation of the subunit proteins at the GABAergic synapse may be induced by GABAergic innervation.


Subject(s)
Cerebellum/metabolism , Mice, Neurologic Mutants/metabolism , Receptors, GABA-A/metabolism , Synaptic Membranes/metabolism , gamma-Aminobutyric Acid/metabolism , Animals , Animals, Newborn , Cell Differentiation/genetics , Cerebellum/abnormalities , Cerebellum/cytology , Immunohistochemistry , Mice , Mice, Neurologic Mutants/abnormalities , Mice, Neurologic Mutants/genetics , Neural Pathways/abnormalities , Neural Pathways/cytology , Neural Pathways/metabolism , Presynaptic Terminals/metabolism , Protein Subunits/genetics , Protein Subunits/metabolism , Receptors, GABA-A/genetics , Synaptic Membranes/genetics , Synaptic Transmission/genetics
18.
Hepatogastroenterology ; 50(51): 666-9, 2003.
Article in English | MEDLINE | ID: mdl-12828056

ABSTRACT

BACKGROUND/AIMS: Recent advances in the treatment of esophageal cancer have afforded better prognosis for patients. Despite the increased need to monitor the progress of patients with reconstructed digestive tracts over the long-term, no reliable prospective studies have yet been conducted. This prospective study determined secondary disease of the reconstructed gastric tube after esophagectomy for esophageal cancer. METHODOLOGY: One hundred and fourteen patients who underwent esophagectomy and reconstructed gastric tube via the posterior mediastinal route between April 1992 and March 1999 at Akita University Hospital, were followed up. Follow-up endoscopy was carried out once a year to determine the incidence and characteristics of secondary disease of the reconstructed gastric tube. RESULTS: Fifty-four (47%) patients were found to have secondary gastric abnormalities. Of these, 4 patients (3.5%) had carcinoma of the gastric tube, 12 patients (10.5%) had benign gastric tumor, 7 patients (6.1%) had gastric ulcers, and 40 patients (35.1%) had erosive or hemorrhagic gastritis. Three patients found to have early gastric cancer upon periodic follow-up endoscopy underwent successful complete resections. CONCLUSIONS: Annual follow-up endoscopy is vital to the detection of early, curative secondary gastric cancer and ulceration in patients following esophagectomy for esophageal cancer.


Subject(s)
Endoscopy, Digestive System , Esophagectomy , Esophagoplasty/methods , Gastritis/pathology , Gastrostomy/methods , Neoplasms, Second Primary/pathology , Postoperative Complications/pathology , Stomach Neoplasms/pathology , Stomach Ulcer/pathology , Stomach/surgery , Aged , Anastomosis, Surgical , Female , Follow-Up Studies , Humans , Male , Middle Aged , Pharynx/surgery , Prospective Studies
19.
Okajimas Folia Anat Jpn ; 79(5): 143-57, 2002 Dec.
Article in English | MEDLINE | ID: mdl-12653463

ABSTRACT

In the mouse optic nerve, the optic nerve fiber layer in the retina, the optic papilla and the lamina cribrosa sclerae (LCS) just after penetrating the eyeball failed to generate myelin, whereas the optic nerve proper in the orbit was occupied by myelinated nerve fibers. The present study investigated development of the architecture of LCS, where the axons develop from unmyelinated to myelinated type, to elucidate how the initial part of axons was unmyelinated. At the LCS of the adult optic nerve, well developed astrocytes densely formed a cytoplasmic mesh-like frame through which unmyelinated fibers passed. The astrocytes here contained numerous and densely packed intermediate glial filaments and cell organelles. This framework formed by astrocytes appeared to be completed between 7 and 14 postnatal days before oligodendrocyte progenitors, migrated from the chiasm side, reached the proximal end of LCS, and began myelin formation. Thus the failure in myelin formation at the intraocular part and LCS possibly depended upon unsuccessful migration of oligodendrocytes beyond LCS constructed by specialized astrocytes, although other inhibitory factors for myelin formation, such as adhesion molecules distributed around LCS, may be unsolved.


Subject(s)
Astrocytes/ultrastructure , Myelin Sheath/physiology , Optic Nerve/cytology , Optic Nerve/embryology , Animals , Mice , Mice, Inbred C57BL , Microscopy, Electron , Oligodendroglia/ultrastructure
20.
Clin Res Cardiol ; 101(7): 545-51, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22322568

ABSTRACT

BACKGROUND: How coronary distensibility contributes to stable or unstable clinical manifestations remains obscure. We postulated that the heterogeneous plaque distensibility is associated with unstable clinical presentations in patients with acute coronary syndrome (ACS). METHODS AND RESULTS: Seventeen and 19 ACS-related and -unrelated lesions, respectively, were visualized using intravascular ultrasound imaging with simultaneous intracoronary pressure recording. Systolic and diastolic lumen cross-sectional areas were measured at the lesion site and at five evenly spaced sites between the proximal and distal reference sites. The coronary distensibility index and stiffness index ß were calculated for each site and averaged for each coronary segment. Maximal distensibility index, standard deviation and the difference between maximal and minimal distensibility indices within each segment were significantly higher in the ACS-related than -unrelated plaques (5.6 ± 2.3 vs. 3.7 ± 1.8, p < 0.001, 2.1 ± 0.9 vs. 1.1 ± 0.6, p < 0.001 and 5.3 ± 2.3 vs. 2.8 ± 1.5, p < 0.001, respectively). Moreover, the difference in the distensibility index between the lesion site of ACS-related plaques and the immediate proximal site was significantly larger (2.88 ± 2.35 vs. 1.17 ± 1.44, p = 0.022) than that in ACS-unrelated plaques. CONCLUSIONS: Coronary artery distensibility is longitudinally more heterogeneous in ACS-related than-unrelated plaques, especially between the lesion and the immediate proximal site.


Subject(s)
Acute Coronary Syndrome/etiology , Coronary Artery Disease/complications , Coronary Vessels/pathology , Coronary Vessels/physiopathology , Vascular Stiffness , Acute Coronary Syndrome/diagnosis , Acute Coronary Syndrome/pathology , Acute Coronary Syndrome/physiopathology , Aged , Analysis of Variance , Angina Pectoris/etiology , Angina Pectoris/pathology , Angina Pectoris/physiopathology , Blood Pressure , Coronary Angiography , Coronary Artery Disease/diagnosis , Coronary Artery Disease/pathology , Coronary Artery Disease/physiopathology , Coronary Vessels/diagnostic imaging , Female , Humans , Japan , Male , Middle Aged , Plaque, Atherosclerotic , Predictive Value of Tests , Ultrasonography, Interventional
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