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Abstract
Abstract
[14C]Mepitiostane in various vehicles was administered to the small intestine of anaesthetized rats with cannulated thoracic ducts, and the effect of lipids on lymphatic absorption was examined. The extent of lymphatic absorption was greatest when administered in triolein and sesame oil, which are triglycerides of long-chain fatty acids. Absorption in the presence of other vehicles was in the order of 10% Tween 80 aqueous solution > monolein > oleic acid ∼ oleic acid/monolein (2:1 mol/mol) > aqueous suspension. Differences between the extents of lymphatic absorption of mepitiostane in the various formulations were not due to variation in the lymph flow but to the increased secretion of chylomicron and very low density lipoproteins. During absorption of mepitiostane from the small intestine, oil affected not only the penetration into epithelium cells and the metabolism in them, but also the partition between blood and lymph.
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Affiliation(s)
- T Ichihashi
- Shionogi Research Laboratories, Shionogi & Co. Ltd, Osaka, Japan
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2
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Abstract
Abstract
The effects of bile and site of gastrointestinal absorption on the lymphatic absorption of the highly lipophilic drug, mepitiostane were examined using thoracic duct-cannulated rats. The lymphatic absorption from the small intestine was very small in the absence of bile compared with that when bile was present. The lymphatic absorption was greatest when drug was administered to the upper small intestine with bile, was smaller for the lower regions of the small intestine, and was negligible for the stomach and the large intestine. A correlation was observed between the extent of lymphatic absorption and the secretion of chylomicron and very low density lipoproteins after administration to various regions with or without bile. The portal absorption data of mepitiostane confirmed that site specificity occurs in the partition of drug between blood and lymph.
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Affiliation(s)
- T Ichihashi
- Shionogi Research Laboratories, Shionogi & Co. Ltd, Osaka, Japan
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3
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Sugimura Y, Murase T, Oyama K, Uchida A, Sato N, Hayasaka S, Kano Y, Takagishi Y, Hayashi Y, Oiso Y, Murata Y. Prevention of neural tube defects by loss of function of inducible nitric oxide synthase in fetuses of a mouse model of streptozotocin-induced diabetes. Diabetologia 2009; 52:962-71. [PMID: 19283362 DOI: 10.1007/s00125-009-1312-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2008] [Accepted: 02/08/2009] [Indexed: 12/12/2022]
Abstract
AIMS/HYPOTHESIS Maternal diabetes during pregnancy increases the risk of congenital malformations such as neural tube defects (NTDs). Although the mechanism of this effect is uncertain, it is known that levels of nitric oxide synthase (NOS) and nitric oxide are elevated in embryos of a mouse model of diabetes. We postulated that overproduction of nitric oxide causes diabetes-induced congenital malformations and that inhibition of inducible NOS (iNOS) might prevent diabetic embryopathy. METHODS Mice were rendered hyperglycaemic by intraperitoneal injection of streptozotocin. The incidence of congenital malformations including NTDs was evaluated on gestational day 18.5. We assessed the involvement of iNOS in diabetes-induced malformation by administering ONO-1714, a specific inhibitor of iNOS, to pregnant mice with streptozotocin-induced diabetic mice and by screening mice with iNOS deficiency due to genetic knockout (iNos(-/-)). RESULTS ONO-1714 markedly reduced the incidence of congenital anomalies, including NTDs, in fetuses of a mouse model of diabetes. It also prevented apoptosis in the head region of fetuses, indicating that iNOS is involved in diabetes-related congenital malformations. Indeed, no NTDs were observed in fetuses of diabetic iNos(-/-) mice and the incidence of other malformations was also markedly reduced. CONCLUSIONS/INTERPRETATION We conclude that increased iNOS activity during organogenesis plays a crucial role in the pathogenesis of diabetes-induced malformations and suggest that inhibitors of iNOS might help prevent malformations, especially NTDs, in diabetic pregnancy.
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Affiliation(s)
- Y Sugimura
- Department of Genetics, Research Institute of Environmental Medicine, Nagoya University, Chikusa-ku, Nagoya, Japan
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4
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Dobrzynski H, Li J, Tellez J, Greener ID, Nikolski VP, Wright SE, Parson SH, Jones SA, Lancaster MK, Yamamoto M, Honjo H, Takagishi Y, Kodama I, Efimov IR, Billeter R, Boyett MR. Computer three-dimensional reconstruction of the sinoatrial node. Circulation 2005; 111:846-54. [PMID: 15699261 DOI: 10.1161/01.cir.0000152100.04087.db] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND There is an effort to build an anatomically and biophysically detailed virtual heart, and, although there are models for the atria and ventricles, there is no model for the sinoatrial node (SAN). For the SAN to show pacemaking and drive atrial muscle, theoretically, there should be a gradient in electrical coupling from the center to the periphery of the SAN and an interdigitation of SAN and atrial cells at the periphery. Any model should include such features. METHODS AND RESULTS Staining of rabbit SAN preparations for histology, middle neurofilament, atrial natriuretic peptide, and connexin (Cx) 43 revealed multiple cell types within and around the SAN (SAN and atrial cells, fibroblasts, and adipocytes). In contrast to atrial cells, all SAN cells expressed middle neurofilament (but not atrial natriuretic peptide) mRNA and protein. However, 2 distinct SAN cell types were observed: cells in the center (leading pacemaker site) were small, were organized in a mesh, and did not express Cx43. In contrast, cells in the periphery (exit pathway from the SAN) were large, were arranged predominantly in parallel, often expressed Cx43, and were mixed with atrial cells. An approximately 2.5-million-element array model of the SAN and surrounding atrium, incorporating all cell types, was constructed. CONCLUSIONS For the first time, a 3D anatomically detailed mathematical model of the SAN has been constructed, and this shows the presence of a specialized interface between the SAN and atrial muscle.
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5
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Dobrzynski H, Marples DD, Musa H, Yamanushi TT, Henderson Z, Takagishi Y, Honjo H, Kodama I, Boyett MR. Distribution of the muscarinic K+ channel proteins Kir3.1 and Kir3.4 in the ventricle, atrium, and sinoatrial node of heart. J Histochem Cytochem 2001; 49:1221-34. [PMID: 11561006 DOI: 10.1177/002215540104901004] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The functionally important effects on the heart of ACh released from vagal nerves are principally mediated by the muscarinic K+ channel. The aim of this study was to determine the abundance and cellular location of the muscarinic K+ channel subunits Kir3.1 and Kir3.4 in different regions of heart. Western blotting showed a very low abundance of Kir3.1 in rat ventricle, although Kir3.1 was undetectable in guinea pig and ferret ventricle. Although immunofluorescence on tissue sections showed no labeling of Kir3.1 in rat, guinea pig, and ferret ventricle and Kir3.4 in rat ventricle, immunofluorescence on single ventricular cells from rat showed labeling in t-tubules of both Kir3.1 and Kir3.4. Kir3.1 was abundant in the atrium of the three species, as shown by Western blotting and immunofluorescence, and Kir3.4 was abundant in the atrium of rat, as shown by immunofluorescence. Immunofluorescence showed Kir3.1 expression in SA node from the three species and Kir3.4 expression in the SA node from rat. The muscarinic K+ channel is activated by ACh via the m2 muscarinic receptor and, in atrium and SA node from ferret, Kir3.1 labeling was co-localized with m2 muscarinic receptor labeling throughout the outer cell membrane.
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Affiliation(s)
- H Dobrzynski
- School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
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6
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Siddiq A, Miyazaki T, Takagishi Y, Kanou Y, Hayasaka S, Inouye M, Seo H, Murata Y. Expression of ZAKI-4 messenger ribonucleic acid in the brain during rat development and the effect of hypothyroidism. Endocrinology 2001; 142:1752-9. [PMID: 11316738 DOI: 10.1210/endo.142.5.8156] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We identified ZAKI-4 (also designated as DSCR1L1) as a thyroid hormone responsive gene in cultured human skin fibroblasts. Recently it has been reported that ZAKI-4 belongs to an evolutionary conserved family of proteins that function as calcineurin inhibitor. In human, ZAKI-4 and calcineurin are highly expressed in brain, where thyroid hormones play essential roles in the development during fetal and neonatal periods. In the present study, we examined the temporal and spatial expression patterns of ZAKI-4 messenger RNA (mRNA) in control and hypothyroid rat brains. Northern blot analysis revealed that ZAKI-4 mRNA was detected in both cerebral cortex and cerebellum as early as embryonic day (E)18. In the cerebral cortex, the expression level gradually increased with age, reaching a plateau at postnatal day (P)7 and remained constant thereafter until P30. A similar pattern of increase with age was also observed in hypothyroid rats; however, the magnitude of the increase was significantly reduced. In control rats, the fold increase in ZAKI-4 mRNA level from E18 to P17 was 10.8; whereas in hypothyroid rats, it was 7.4. In cerebellum the expression level did not change with age or by thyroid status. In situ hybridization revealed that ZAKI-4 mRNA is widely expressed in neurons throughout the brain. It is noteworthy that the expression in the neurons of layer VI of the cerebral cortex was more evident in control rats than that in hypothyroid rats from P17 to P30. Though not influenced by hypothyroidism, there were several regions of the brain in which ZAKI-4 mRNA was strongly expressed. These regions were the mitral cell layer of the olfactory bulb, the substantia nigra, and the hippocampus, where calcineurin is also abundantly expressed. Therefore, it may be hypothesized that ZAKI-4 plays an important role in the development and function of the brain by modulating calcineurin function; and decrease in ZAKI-4 mRNA expression in the specific brain areas may explain, in some parts, the mechanism of abnormal brain development by hypothyroidism.
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Affiliation(s)
- A Siddiq
- Department of Teratology and Genetics, Division of Molecular and Cellular Adaptation, Research Institute of Environmental Medicine, Nagoya University, Nagoya 464-8601, Japan
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7
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Park YG, Hayasaka S, Takagishi Y, Inouye M, Okumoto M, Oda S. Histological characteristics of the pelage skin of rough fur mice (C3H/HeJ- ruf/ruf). Exp Anim 2001; 50:179-82. [PMID: 11381623 DOI: 10.1538/expanim.50.179] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Pelage skin of C3H/HeJ mice homozygous at an autosomal recessive mutant locus, rough fur (ruf) which is located on chromosome 9, was histologically analyzed. Sebaceous glands synthesizing lipids were larger in the mutant mice than in controls in an examination by Sudan IV staining. Electron microscopic analysis of the sebaceous gland showed that lipid droplets were denser in mutant mice than in control mice, and that they were irregular in shape in ruf mice while those of controls were round. Our results suggested that rough fur (ruf) mice might be an animal model for hyperlipogenesis of the pelage skin.
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Affiliation(s)
- Y G Park
- Department of Laboratory Animal Science, Division of Veterinary Sciences, Graduate School of Agriculture and Biological Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531, Japan
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8
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Emdad L, Uzzaman M, Takagishi Y, Honjo H, Uchida T, Severs NJ, Kodama I, Murata Y. Gap junction remodeling in hypertrophied left ventricles of aortic-banded rats: prevention by angiotensin II type 1 receptor blockade. J Mol Cell Cardiol 2001; 33:219-31. [PMID: 11162128 DOI: 10.1006/jmcc.2000.1293] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Remodeling of gap-junctional organization in hypertrophied left ventricle (LV) in response to pressure overload in rats induced by abdominal aorta banding was investigated by immunoconfocal and electron microscopy. Eight to 12 weeks after banding, rats developed significant LV hypertrophy. In contrast to control LV myocytes, which showed connexin43 (Cx43) labeling largely confined to the intercalated disks, LV myocytes from aortic-banded rats showed dispersion of punctate Cx43 labeling over the entire cell surface. In LV tissues sectioned longitudinally, the proportion of Cx43 label at the intercalated disk decreased significantly (control, 0.87 v aortic-banded, 0.62). En-face views of intercalated disks of hypertrophied myocardium revealed a reduction of Cx43 gap junctions in the disk center, giving rise to a significant decrease in the proportion of the disk occupied by gap-junctional membrane (control, 0.32 v aortic-banded, 0.24). Electron microscopy of hypertrophied LV tissue revealed that Cx43-containing gap junctions were frequently displaced from their usual locations to form side-to-side contacts distant from the disk, and also appeared as annular profiles. In aortic-banded rats treated with the angiotensin II (AII) type 1 receptor (AT1) antagonist, losartan (10 mg/kg/day, 11 weeks) not only LV hypertrophy, but also the gap junction disorganization was markedly reduced. These results suggest that LV hypertrophy induced by pressure overload is associated with Cx43 gap junction disorganization and that AII may play an important role either directly or indirectly in gap-junctional remodeling.
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Affiliation(s)
- L Emdad
- Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
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9
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Takagishi Y, Yasui K, Severs NJ, Murata Y. Species-specific difference in distribution of voltage-gated L-type Ca(2+) channels of cardiac myocytes. Am J Physiol Cell Physiol 2000; 279:C1963-9. [PMID: 11078712 DOI: 10.1152/ajpcell.2000.279.6.c1963] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ca(2+) influx via sarcolemmal voltage-dependent Ca(2+) channels (L-type Ca(2+) channels) is the fundamental step in excitation-contraction (E-C) coupling in cardiac myocytes. Physiological and pharmacological studies reveal species-specific differences in E-C coupling resulting from a difference in the contribution of Ca(2+) influx and intracellular Ca(2+) release to activation of contraction. We investigated the distribution of L-type Ca(2+) channels in isolated cardiac myocytes from rabbit and rat ventricle by correlative immunoconfocal and immunogold electron microscopy. Immunofluorescence labeling revealed discrete spots in the surface plasma membrane and transverse (T) tubules in rabbit myocytes. In rat myocytes, labeling appeared more intense in T tubules than in the surface sarcolemma. Immunogold electron microscopy extended these findings, showing that the number of gold particles in the surface plasma membrane was significantly higher in rabbit than rat myocytes. In rabbit myocyte plasma membrane, the gold particles were distributed as clusters in both regions that were associated with junctional sarcoplasmic reticulum and those that were not. The findings are consistent with the idea that influx of Ca(2+) via surface sarcolemmal Ca(2+) channels contributes to intracellular Ca(2+) to a greater degree in rabbit than in rat myocytes.
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Affiliation(s)
- Y Takagishi
- Department of Teratology and Genetics, Research Institute of Environmental Medicine, Nagoya University, Nagoya 464-8601, Japan.
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10
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Gathercole DV, Colling DJ, Skepper JN, Takagishi Y, Levi AJ, Severs NJ. Immunogold-labeled L-type calcium channels are clustered in the surface plasma membrane overlying junctional sarcoplasmic reticulum in guinea-pig myocytes-implications for excitation-contraction coupling in cardiac muscle. J Mol Cell Cardiol 2000; 32:1981-94. [PMID: 11040103 DOI: 10.1006/jmcc.2000.1230] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ca(2+) release through ryanodine receptors, located in the membrane of the junctional sarcoplasmic reticulum (SR), initiates contraction of cardiac muscle. Ca(2+)influx through plasma membrane L-type Ca(2+)channels is thought to be an important trigger for opening ryanodine receptors ("Ca(2+)-induced Ca(2+)-release"). Optimal transmission of the transmembrane Ca(2+)influx signal to SR release is predicted to involve spatial juxtaposition of L-type Ca(2+)channels to the ryanodine receptors of the junctional SR. Although such spatial coupling has often been implicitly assumed, and data from immunofluorescence microscopy are consistent with its existence, the definitive demonstration of such a structural organization in mammalian tissue is lacking at the electron-microscopic level. To determine the spatial distribution of plasma membrane L-type Ca(2+)channels and their location in relation to underlying junctional SR, we applied two high-resolution immunogold-labeling techniques, label-fracture and cryothin-sectioning, combined with quantitative analysis, to guinea-pig ventricular myocytes. Label-fracture enabled visualization of colloidal gold-labeled L-type Ca(2+)channels in planar freeze-fracture electron-microscopic views of the plasma membrane. Mathematical analysis of the gold label distribution (by nearest-neighbor distance distribution and the radial distribution function) demonstrated genuine clustering of the labeled channels. Gold-labeled cryosections showed that labeled L-type Ca(2+)channels quantitatively predominated in domains of the plasma membrane overlying junctional SR. These findings provide an ultrastructural basis for functional coupling between L-type Ca(2+)channels and junctional SR and for excitation-contraction coupling in guinea-pig cardiac muscle.
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Affiliation(s)
- D V Gathercole
- National Heart and Lung Institute, Imperial College of Science, Technology and Medicine, London, UK
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11
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Miyata M, Finch EA, Khiroug L, Hashimoto K, Hayasaka S, Oda SI, Inouye M, Takagishi Y, Augustine GJ, Kano M. Local calcium release in dendritic spines required for long-term synaptic depression. Neuron 2000; 28:233-44. [PMID: 11086997 DOI: 10.1016/s0896-6273(00)00099-4] [Citation(s) in RCA: 208] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We have used rats and mice with mutations in myosin-Va to evaluate the range and function of IP3-mediated Ca2+ signaling in dendritic spines. In these mutants, the endoplasmic reticulum and its attendant IP3 receptors do not enter the postsynaptic spines of parallel fiber synapses on cerebellar Purkinje cells. Long-term synaptic depression (LTD) is absent at the parallel fiber synapses of the mutants, even though the structure and function of these synapses otherwise appear normal. This loss of LTD is associated with selective changes in IP3-mediated Ca2+ signaling in spines and can be rescued by photolysis of a caged Ca2+ compound. Our results reveal that IP3 must release Ca2+ locally in the dendritic spines to produce LTD and indicate that one function of dendritic spines is to target IP3-mediated Ca2+ release to the proper subcellular domain.
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Affiliation(s)
- M Miyata
- Laboratory for Cellular Neurophysiology, Brain Science Institute, RIKEN, Saitama, Japan
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12
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Futaki S, Takagishi Y, Hayashi Y, Ohmori S, Kanou Y, Inouye M, Oda S, Seo H, Iwaikawa Y, Murata Y. Identification of a novel myosin-Va mutation in an ataxic mutant rat, dilute-opisthotonus. Mamm Genome 2000; 11:649-55. [PMID: 10920234 DOI: 10.1007/s003350010121] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Mutations of the myosin-Va gene (Myo5a) cause diluted coat color in mice and are occasionally associated with severe neurological disorders. Dilute-opisthotonus (dop) is a spontaneous gene mutation in the rat, and phenotypes of the homozygote (dop/dop) are similar to those of the Myo5a-deficient mouse, suggesting that the mutation resides in the rat Myo5a gene. To elucidate the molecular basis of the dop mutation, we cloned the rat Myo5a cDNA from the wild type and the dop/dop. The wild-type rat Myo5a cDNA contained a 5487-bp ORF and showed higher homology with Myo5a of the other species than Myr6 (Myo5b) in the rat. A 141-bp in-frame deletion was detected in the head region in the dop cDNA. An intragenic rearrangement consisting of a 306-bp inversion associated with 17-bp and 217-bp deletions were identified in the Myo5a gene of the dop genome. This rearrangement involved a 141-bp exon, which was skipped in the dop transcript. The MyoVA protein expression was severely impaired in the dop/dop brain. This is the first report to define the dop mutation as the Myo5a gene abnormality in the rat.
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MESH Headings
- Amino Acid Sequence
- Animals
- Ataxia/genetics
- Base Sequence
- Blotting, Northern
- Blotting, Southern
- Brain/metabolism
- Cloning, Molecular
- DNA Mutational Analysis
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- Female
- Gene Expression
- Genotype
- Intermediate Filament Proteins/genetics
- Intermediate Filament Proteins/metabolism
- Male
- Molecular Sequence Data
- Mutation
- Myosin Heavy Chains
- Myosin Type V
- Pedigree
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Inbred Strains
- Sequence Homology, Amino Acid
- Sequence Homology, Nucleic Acid
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Affiliation(s)
- S Futaki
- Graduate School of Human Informatics, Nagoya University, Nagoya 464-8601, Japan
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13
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Takeuchi S, Takagishi Y, Yasui K, Murata Y, Toyama J, Kodama I. Voltage-gated K(+)Channel, Kv4.2, localizes predominantly to the transverse-axial tubular system of the rat myocyte. J Mol Cell Cardiol 2000; 32:1361-9. [PMID: 10860776 DOI: 10.1006/jmcc.2000.1172] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Kv4.2 subunit, a member of K(+)channel gene family, is considered to play a major role in the formation of depolarization-activated transient outward K(+)current channels in the mammalian heart. We investigated the subcellular localization of Kv4.2 subunit in the rat heart by immunofluorescence and immunoelectron microscopy. In atrial cells, Kv4.2 immunofluorescent staining was intensely observed in the peripheral sarcolemma and the intercalated disks, but seldom found in transverse tubules, which are rare or absent in atrial cells. In ventricular cells, the labeling of Kv4.2 immunofluorescent staining was found throughout the entire cell membrane, and the staining was stronger in the transverse-axial tubular system than in the peripheral sarcolemma. Correlative immunoconfocal and immunoelectron microscopy using FluoroNanogold confirmed that Kv4.2 distributed in the transverse-axial tubular system including the longitudinally oriented axial tubules. Immunogold electron microscopy of ultrathin cryosections revealed that Kv4.2 was distributed on the plasma membranes of the T-tubules. The extensive distribution of Kv4.2 on the entire cell membrane of myocytes would provide rat myocardial cells with a large capability for the transport of K(+)ions through the channels in the repolarization phase.
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Affiliation(s)
- S Takeuchi
- Department of Circulation, Nagoya University, Nagoya, Japan
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14
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Dobrzynski H, Rothery SM, Marples DD, Coppen SR, Takagishi Y, Honjo H, Tamkun MM, Henderson Z, Kodama I, Severs NJ, Boyett MR. Presence of the Kv1.5 K(+) channel in the sinoatrial node. J Histochem Cytochem 2000; 48:769-80. [PMID: 10820151 DOI: 10.1177/002215540004800606] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The aim of this study was to establish, using immunolabeling, whether the Kv1.5 K(+) channel is present in the pacemaker of the heart, the sinoatrial (SA) node. In the atrial muscle surrounding the SA node and in the SA node itself (from guinea pig and ferret), Western blotting analysis showed a major band of the expected molecular weight, approximately 64 kD. Confocal microscopy and immunofluorescence labeling showed Kv1.5 labeling clustered in atrial muscle but punctate in the SA node. In atrial muscle, Kv1.5 labeling was closely associated with labeling of Cx43 (gap junction protein) and DPI/II (desmosomal protein), whereas in SA node Kv1.5 labeling was closely associated with labeling of DPI/II but not labeling of Cx43 (absent in the SA node) or Cx45 (another gap junction protein present in the SA node). Electron microscopy and immunogold labeling showed that the Kv1.5 labeling in atrial muscle is preferentially associated with desmosomes rather than gap junctions.
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Affiliation(s)
- H Dobrzynski
- School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
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15
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Uzzaman M, Honjo H, Takagishi Y, Emdad L, Magee AI, Severs NJ, Kodama I. Remodeling of gap junctional coupling in hypertrophied right ventricles of rats with monocrotaline-induced pulmonary hypertension. Circ Res 2000; 86:871-8. [PMID: 10785509 DOI: 10.1161/01.res.86.8.871] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The present study investigates the remodeling of gap junctional organization in relation to changes in anisotropic conduction properties in hypertrophied right ventricles (RVs) of rats with monocrotaline (MCT)-induced pulmonary hypertension. In contrast to controls that showed immunolocalization of connexin43 (Cx43) labeling largely confined to the intercalated disks, RV myocytes from MCT-treated rats showed dispersion of Cx43 labeling over the entire cell surface. The disorganization of Cx43 labeling became more pronounced with the progression of hypertrophy. Desmoplakin remained localized to the intercalated disks, as in controls. In RV tissues, the proportion of Cx43 label at the intercalated disk progressively decreased. Quantitative analysis of en face views of intercalated disks revealed a significant decrease in the disk gap junctional density in RV tissues of MCT-treated rats (control, 0.18 versus MCT-treated, 0.14 at 2 weeks; control, 0.16 versus MCT-treated, 0.11 at 4 weeks). Conduction velocity in RVs parallel to the fiber orientation was significantly lower (30.2% [n=9]) in MCT-treated rats at 4 weeks than in control rats, whereas there was no significant difference observed in the conduction velocity across the fiber orientation between control and MCT-treated rats. The anisotropic ratio of MCT-treated rats (1.38+/-0.10) was significantly lower than that of control rats (1.98+/-0.12). These results suggest that RV hypertrophy induced by pressure overload is associated with both disorganization of gap junction distribution and alteration of anisotropic conduction properties.
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Affiliation(s)
- M Uzzaman
- Department of Circulation, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
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16
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Yanagi T, Mizoguchi J, Adachi T, Sato S, Kodama K, Anzai K, Takagishi Y, Kamei C, Fujiwara M, Matsushita T, Yamashoji Y, Inoue Y. Preparation and characterization of two crystalline forms of 4-amino-5-chloro-2-methoxy-N-[(2S,4S)-1-ethyl-2-hydroxymethyl-4-pyrroli dinyl]benzamide (TKS159). Chem Pharm Bull (Tokyo) 2000; 48:366-9. [PMID: 10726859 DOI: 10.1248/cpb.48.366] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
For 4-amino-5-chloro-2-methoxy-N-[(2S,4S)-1-ethyl-2-hydroxymethyl-4-pyrrolid inyl]benzamide (TKS159), two polymorphs, forms alpha and beta, were prepared and characterized by means of X-ray powder diffractometry, thermal analysis, infrared spectroscopy and 13C-NMR spectroscopy, both in the solution and solid phases. The X-ray powder diffraction analysis gave different patterns for forms alpha and beta. In the thermogravimetry and differential thermal analysis profiles, form beta exhibited characteristic endo- and exothermic peaks at 112.7 degrees C and 116.2 degrees C, respectively, due to the partial melting-induced phase transition to form alpha without accompanying weight loss, and these were followed by an additional endothermic peak at 138.2 degrees C due to fusion. For form alpha, only an endothermic peak at 137.8 degrees C due to fusion was observed. The IR spectroscopic analyses of forms alpha and beta gave different absorption bands assigned to N-H and O-H stretching, N-H bending, and C=O stretching vibrations. From the data obtained by thermal analysis, form alpha was shown to be thermodynamically more stable than form beta.
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Affiliation(s)
- T Yanagi
- Research and Development Department, Teikoku Chemical Industries Co., Ltd., Itami, Hyogo, Japan
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17
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Darmanto W, Inouye M, Takagishi Y, Ogawa M, Mikoshiba K, Murata Y. Derangement of Purkinje cells in the rat cerebellum following prenatal exposure to X-irradiation: decreased Reelin level is a possible cause. J Neuropathol Exp Neurol 2000; 59:251-62. [PMID: 10744063 DOI: 10.1093/jnen/59.3.251] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
It has been reported that prenatal X-irradiation of rats during the late gestation period causes heterotopic Purkinje cells in the internal granular layer (IGL) of the abnormally foliated cerebellum. The present study was designed to demonstrate the process of X-ray-induced derangement of Purkinje cells and their surrounding cells. In addition, the expression of some morphoregulatory molecules was examined to determine which molecules are involved in the abnormal pattern of Purkinje cells. Pregnant rats (n = 22) were exposed to 2.5 Gy X-radiation on gestation day 21 and the cerebellum of progeny was examined histologically and by immunohistochemistry to identify Purkinje and Bergmann cells. At 12 h after exposure, extensive cell death was observed in the external granular layer (EGL). By postnatal day (P) 9, while Purkinje cells with well-developed dendrites aligned underneath the EGL in the control cerebellum, Purkinje cells with shorter and abnormally oriented dendrites failed to align and remained in the heterotopic location in the IGL. Bergmann cells and their fibers were also disoriented but later recovered in their proper position. Abnormal folia developed in the irradiated rats. Using immunohistochemistry, we next examined the levels of the neural cell adhesion molecule (NCAM), fibronectin, tenascin, and Reelin. Among them, only the level of Reelin was affected significantly. Reelin decreased strikingly in the premigratory zone of the EGL and IGL in the irradiated cerebellum on P1, and the decrease continued until P9. Decreased Reelin expression was demonstrated quantitatively by Northern blot analysis and the correlation between the mRNA and protein levels was well presented. The expression of reelin mRNA decreased significantly by irradiation from P0, being almost one third of the level in controls on P4, and tended to recover up to P9. It is thus indicated that X-irradiation causes a marked decrease in the level of Reelin at the critical stage for the alignment of Purkinje cells. Since Reelin has been shown to play an important role in the migration of neural cells, it is suggested that the decrease in Reelin by X-irradiation is an important factor for the derangement of Purkinje cells.
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Affiliation(s)
- W Darmanto
- Research Institute of Environmental Medicine, Nagoya University, Japan
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18
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Coppen SR, Kodama I, Boyett MR, Dobrzynski H, Takagishi Y, Honjo H, Yeh HI, Severs NJ. Connexin45, a major connexin of the rabbit sinoatrial node, is co-expressed with connexin43 in a restricted zone at the nodal-crista terminalis border. J Histochem Cytochem 1999; 47:907-18. [PMID: 10375379 DOI: 10.1177/002215549904700708] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The pacemaker of the heart, the sinoatrial (SA) node, is characterized by unique electrical coupling properties. To investigate the contribution of gap junction organization and composition to these properties, the spatial pattern of expression of three gap junctional proteins, connexin45 (Cx45), connexin40 (Cx40), and connexin43 (Cx43), was investigated by immunocytochemistry combined with confocal microscopy. The SA nodal regions of rabbits were dissected and rapidly frozen. Serial cryosections were double labeled for Cx45 and Cx43 and for Cx40 and Cx43, using pairs of antibody probes raised in different species. Dual-channel scanning confocal microscopy was applied to allow simultaneous visualization of the different connexins. Cx45 and Cx40, but not Cx43, were expressed in the central SA node. The major part of the SA nodal-crista terminalis border revealed a sharply demarcated boundary between Cx43-expressing myocytes of the crista terminalis and Cx45/Cx40-expressing myocytes of the node. On the endocardial side, however, a transitional zone between the crista terminalis and the periphery of the node was detected in which Cx43 and Cx45 expression merged. These distinct patterns of connexin compartmentation and merger identified suggest a morphological basis for minimization of contact between the tissues, thereby restricting the hyperpolarizing influence of the atrial muscle on the SA node while maintaining a communication route for directed exit of the impulse into the crista terminalis.
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Affiliation(s)
- S R Coppen
- National Heart and Lung Institute, Imperial College School of Medicine, London, United Kingdom
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19
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Darmanto W, Inouye M, Hayasaka S, Takagishi Y, Ogawa M, Mikoshiba K, Murata Y. Disturbed Purkinje cell migration due to reduced expression of Reelin by X-irradiation in developing rat cerebellum. Biol Sci Space 1998; 12:254-5. [PMID: 11542484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
The major histogenetic events of the rat cerebellum take place in the early postnatal days. During this period, precursors of microneurons, such as granule cells, form the external granular layer (EGL), extend over the surface of the primordial cerebellum, and actively proliferate. Postmitotic granule cells leave the EOL and migrate to the internal granular layer (IGL). On the other hand, guided by radial glial fibers, immature Purkinje cells migrate from the ventricular zone of the fourth ventricle and settle in the Purkinje cell plate with thickness of several cells. Various cell adhesion molecules are involved in the interaction between the migratory immature Purkinje cells and processes of the radial glia as the basis for contact guidance. The second process is the formation of immature Purkinje cells to the monolayer. This process takes place at the first week after birth of the rat and cell adhesion molecules such as neural cell adhesion molecule (NCAM), fibronectin, tenascin and Reelin are also suggested to play an important role for the cell patterning. When rat fetuses are exposed to X-radiation in the last gestation period, abnormal foliation of the cerebellum develops with ectopic Purkinje cells. The molecular mechanism that contributes to abnormal migration of Purkinje cells and foliar malformation induced by X-irradiation in the cerebellum are not yet clear. This study was undertaken to elucidate the mechanisms of ectopic Purkinje cell formation by examining the expression of cell adhesion molecules.
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Affiliation(s)
- W Darmanto
- Research Institute of Environmental Medicine, Nagoya University
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20
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Inouye M, Funahashi A, Nakamura E, Takahashi S, Kubota Y, Takagishi Y, Hayasaka S, Murata Y. [Comparison of the effects of accelerated heavy ions and X-rays on the development of rat brain]. Biol Sci Space 1998; 12:188-9. [PMID: 12512525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Affiliation(s)
- M Inouye
- Res. Inst. Environ. Med., Nagoya Univ
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21
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Darmanto W, Inouye M, Hayasaka S, Takagishi Y, Aolad HM, Murata Y. Dose response relationship of disturbed migration of Purkinje cells in the cerebellum due to X-irradiation. Environ Med 1998; 42:46-50. [PMID: 12212618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
Pregnant rats were exposed to 2.0, 2.25 or 2.5 Gy X-irradiation on gestation day 21. Pups were sacrificed 12 hr after exposure, and on postnatal day 5 (P5), P7 and P9. Their cerebella were observed immunohistochemically using anti-inositol 1,4,5 triphosphate (IP3) receptor antibody to identify Purkinje cells. These cells were disturbed to migrate and remained in the internal granular layer and white matter of the cerebellum. They had short dendrites, and some showed an abnormal direction of dendrites in rats exposed to 2.25 or 2.5 Gy. Alignment of Purkinje cells was also disturbed when examined either on P5, P7 or P9 especially by doses of 2.25 and 2.5 Gy. There was a relationship between X-ray doses and the number of cells piling up in the Purkinje cell layer of the cerebellum. The dose-response relationship with the number of ectopic Purkinje cells was noted in the anterior lobes of the cerebellum.
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Affiliation(s)
- W Darmanto
- Department of Teratology and Genetics, Division of Molecular and Cellular Adaptation, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
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22
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Inouye M, Darmanto W, Takagishi Y, Ogawa M, Mikoshiba K, Murata Y. Foliar malformation of the cerebellum in rats caused by X-radiation. Toxicol Lett 1998. [DOI: 10.1016/s0378-4274(98)80244-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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23
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Ichihashi T, Izawa M, Miyata K, Mizui T, Hirano K, Takagishi Y. Mechanism of hypocholesterolemic action of S-8921 in rats: S-8921 inhibits ileal bile acid absorption. J Pharmacol Exp Ther 1998; 284:43-50. [PMID: 9435159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The mechanism of the hypocholesterolemic action of S-8921, methyl 1-(3,4-dimethoxyphenyl)-3-(3-ethylvaleryl)- 4-hydroxy-6,7,8-trimethoxy-2-naphthoate, was examined in rats. In diet-induced hypercholesterolemic rats, 2 weeks oral administration of S-8921 dose- and time-dependently decreased plasma cholesterol level in the daily dose range of 0.1 to 10 mg/kg. Results with the dual-isotope plasma ratio method indicated that S-8921 inhibits cholesterol absorption from the intestine and enhances its elimination from the body. The in situ loop method showed that S-8921 does not inhibit the absorption of cholesterol from rat jejunum, clearly inhibits active absorption of taurocholic acid (TCA) and glycocholic acid (GCA) from rat ileum and does not inhibit passive absorption of cholic acid (CA) from the rat jejunum. In rat ileal brush-border membrane vesicles, S-8921 inhibited the sodium-dependent uptake of TCA in a concentration-dependent manner with IC50 of 2.1 microM, not the Na(+)-dependent D-glucose and L-alanine uptake. These results suggest that S-8921 is a potent, selective inhibitor of the Na(+)-dependent bile acid transport system in the ileal mucosal cell brush-border membrane, and this inhibition is the mechanism by which this drug decreases intestinal bile acid reabsorption to result in a significant decrease of plasma cholesterol.
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Affiliation(s)
- T Ichihashi
- Formulation R & D Laboratories, Shionogi & Co., Ltd., Osaka, Japan
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24
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Kabir N, Yamamura H, Niki I, Iida Y, Uzzaman M, Sarkar D, Hayasaka S, Takagishi Y, Inouye M, Hidaka H. Immunocytochemical detection and spatial distribution of myosin light-chain kinase in preimplantation mouse embryos. J Exp Zool 1997; 278:147-55. [PMID: 9181694 DOI: 10.1002/(sici)1097-010x(19970615)278:3<147::aid-jez4>3.0.co;2-o] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
As a follow-up to our previous study on the role of myosin light-chain kinase (MLCK), a Ca2+/calmodulin-dependent enzyme, in the development of preimplantation mouse embryos, we examined the presence and pattern of distribution of MLCK during preimplantation development of the mouse by whole-mount, indirect immunocytochemistry and by Western blotting, using a monoclonal antibody against MLCK. At all stages of preimplantation development, the nucleus was brightly stained with an unstained region around the nucleus, and regions near the cell membrane were also brightly stained. Using the optical sectioning capability of the confocal laser scanning microscope, we found that, up to the eight-cell stage, the regions of cell contact were mostly unstained, but along with the process of compaction, cell contact regions showed a clear staining pattern along with clearing of the cytoplasm. During formation of the blastocyst, a ring of immunofluorescence was found at the margin of the blastocoel. In the blastocyst, cells of the inner cell mass were less immunofluorescent than trophectoderm cells. These staining results appear to be due to specific immunoreaction between MLCK and the antibody, because the staining patterns were abolished when the antibody was preabsorbed by MLCK purified from chicken gizzard smooth muscle. In Western blotting of blastocysts, we found a band at 130 kD. We also show by immunoblotting and immunohistochemistry of various mouse tissues that the antibody used in this study has cross-reactivity to MLCK of various muscle and non-muscle tissues of the mouse. The presence and spatial distribution of MLCK at various stages of preimplantation development of the mouse suggest that it could play a crucial role in the regulation of the contractile events involved in the initial differentiation that occurs during formation of the mouse blastocyst.
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Affiliation(s)
- N Kabir
- Department of Teratology and Genetics, Nagoya University, Japan
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25
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Takagishi Y, Rothery S, Issberner J, Levi A, Severs NJ. Spatial distribution of dihydropyridine receptors in the plasma membrane of guinea pig cardiac myocytes investigated by correlative confocal microscopy and label-fracture electron microscopy. J Electron Microsc (Tokyo) 1997; 46:165-170. [PMID: 9180031 DOI: 10.1093/oxfordjournals.jmicro.a023504] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Excitation-contraction coupling in cardiac muscle is thought to depend fundamentally on the spatial organization of sarcolemmal dihydropyridine receptors (L-type calcium channels) in relation to ryanodine receptors (calcium-release channels of the sarcoplasmic reticulum). In the present study, we have investigated the distribution of dihydropyridine receptors in the guinea pig myocyte plasma membrane by correlative immunoconfocal microscopy and label-fracture electron microscopy. Label-fracture, a method in freeze-fracture cytochemistry, permits immunogold localization of cell surface proteins in en face membrane views. Taken together, results from confocal microscopy and label-fracture replicas suggest that, in the peripheral plasma membrane, calcium channels are organized predominantly in the form of clusters. Confocal microscopy also suggests a similar organization in the transverse tubules. It is hypothesized that these clusters may lie adjacent to junctional sarcoplasmic reticulum, permitting the close coupling of influx of calcium through plasma membrane calcium channels to trigger release of calcium from the intracellular stores, as part of the mechanism of calcium-induced calcium release.
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Affiliation(s)
- Y Takagishi
- Imperial College School of Medicine, National Heart and Lung Institute, Royal Brompton Hospital, London, UK
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26
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Takagishi Y, Oda S, Hayasaka S, Dekker-Ohno K, Shikata T, Inouye M, Yamamura H. The dilute-lethal (dl) gene attacks a Ca2+ store in the dendritic spine of Purkinje cells in mice. Neurosci Lett 1996; 215:169-72. [PMID: 8899740 DOI: 10.1016/0304-3940(96)12967-0] [Citation(s) in RCA: 124] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The absence of smooth endoplasmic reticulum (SER) in the dendritic spine of Purkinje cells was found in dilute-lethal (dl) mouse cerebella as detected by immunohistochemistry using anti-inositol 1,4,5-triphosphate receptor antibody and electron microscopy. Since SER in the spine has been suggested to play a crucial role for synaptic regulation as an intracellular Ca2+ store (for reviews, see [Miller, R.J., Prog. Neurobiol., 37 (1991) 255-285: Simpson, P.B., Challiss, R.A.J. and Nahorski, S.R., Trends Neurosci., 18 (1995) 299-306]), a neurological defect, characterized by clonic convulsions with opisthotonus and ataxia, in the dilute-lethal mouse with homozygous trait may be attributable to the absence of SER in the dendritic spine of Purkinje cells.
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Affiliation(s)
- Y Takagishi
- Research Institute of Environmental Medicine, Nagoya University, Japan.
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27
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Imamura A, Takagishi Y, Takada S, Uetani Y, Nakamura T, Inagaki Y, Nakamura H. [Cognitive function and MRI findings in very low birth weight infants]. No To Hattatsu 1996; 28:299-305. [PMID: 8753128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Twenty-two very low birth weight infants at preschool ages of 5-6 years were studied to clarify the correlation between cognitive function and MRI findings. Cognitive function was evaluated by the Wechsler Intelligence Scale for Children-Revised (WISC-R) and the Frostig developmental test of visual perception. Ventricular enlargement, assessed by the bioccipital index (B. I.) measured on MRI, was correlated to cognitive disorders. Children with periventricular high intensity areas (T2-weighted images) extending from the posterior periventricular region to the parietal lobe tend to highly suffer from cerebral palsy and visuo-perceptual impairment. These results indicate that the disorders of cognitive function in very low birth weight infants were caused by a damage of association fibers in periventricular areas which was detectable by MRI.
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Affiliation(s)
- A Imamura
- Department of Pediatrics, Kobe University School of Medicine
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28
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Dekker-Ohno K, Hayasaka S, Takagishi Y, Oda S, Wakasugi N, Mikoshiba K, Inouye M, Yamamura H. Endoplasmic reticulum is missing in dendritic spines of Purkinje cells of the ataxic mutant rat. Brain Res 1996; 714:226-30. [PMID: 8861629 DOI: 10.1016/0006-8993(95)01560-4] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Dilute-opisthotonus (dop) is a spontaneous ataxic mutation in the rat, regulated by an autosomal recessive gene. Immunohistochemical staining with anti-inositol 1,4,5-trisphosphate receptor antibody and electron microscopic examinations revealed that the endoplasmic reticulum in dendritic spines of Purkinje cell was missing in the ataxic rat. This could impair the intracellular signal transduction in the parallel fiber-Purkinje cell synapse, and be a cause of the severe ataxic movement.
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Affiliation(s)
- K Dekker-Ohno
- School of Agricultural Sciences, Nagoya University, Nagoya, Japan
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29
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Nagata S, Masuda K, Nogusa H, Hirano K, Takagishi Y. Absence of lysosomal cleavage in the cytotoxicity mechanism of an immunoconjugate composed of anti-alpha-fetoprotein monoclonal antibody and vindesine analog. Biol Pharm Bull 1996; 19:480-3. [PMID: 8924923 DOI: 10.1248/bpb.19.480] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The effect of lysosomal enzyme inhibition on the cytotoxic activity of an immunoconjugate composed of anti-alpha-fetoprotein monoclonal antibody and vindesine analog (VDS) was studied in vitro using human tumor clonogenic assay (HTCA). Addition of the lysosome enzyme inhibitors, leupeptin and ammonium chloride, to the HTCA system had little influence on the cytotoxicity of this immunoconjugate. In separate experiments, no released VDS was detected by HPLC after incubation with the supernatant of rat liver homogenate without inhibitor. These results show that the immunoconjugate may bypass the lysosomal process and exert its activity as an intact or similar form.
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Affiliation(s)
- S Nagata
- Shionogi Research Laboratories, Shionogi & Co., Ltd., Osaka, Japan
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30
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Sun X, Inouye M, Takagishi Y, Hayasaka S, Yamamura H. Follow-up study on histogenesis of microcephaly associated with ectopic gray matter induced by prenatal gamma-irradiation in the mouse. J Neuropathol Exp Neurol 1996; 55:357-65. [PMID: 8786394 DOI: 10.1097/00005072-199603000-00011] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Brain malformation with ectopic gray matter was visualized with magnetic resonance imaging in small-sized heads of prenatally exposed atomic bomb survivors. The identical brain malformation was reproduced in mice and its histogenesis was studied in the present experiment. Pregnant mice were exposed to 60Co gamma-irradiation at a single dose of 1.5 Gy on embryonic day 13 (E13), and then injected intraperitoneally with 30 mg/kg BrdU on E15. The extensive dead cells appeared throughout the brain mantle at 6 hours (h) after exposure. On E16 cell aggregations formed rosettes. On E18 a high proportion of BrdU-labeled cells reached the superficial layers of the cortical plate with the remaining cells located in the ectopic neuronal masses. The quantitative study showed that labeled cells in layers II to III were fewer and those in layers IV to VI more numerous in the prenatally irradiated adult mice than in controls. The anti-GFAP immunostaining revealed that the glial fibers in the irradiated mice were preserved, but disorganized. These findings suggested that the majority of migrating neurons were able to arrive at their normal layers, but some neurons remained due to the interrupted migratory pathway and eventually formed ectopic neuronal masses beneath the subcortical white matter.
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Affiliation(s)
- X Sun
- Department of Teratology, Nagoya University, Japan
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31
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Kabir N, Yamamura H, Takagishi Y, Inouye M, Oda S, Hidaka H. Regulation of preimplantation development of mouse embryos: effects of inhibition of myosin light-chain kinase, a Ca2+/calmodulin-dependent enzyme. J Exp Zool 1996; 274:101-10. [PMID: 8742690 DOI: 10.1002/(sici)1097-010x(19960201)274:2<101::aid-jez3>3.0.co;2-t] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We have examined the effects of ML-9 and wortmannin, which are, respectively, specific reversible and irreversible inhibitors of myosin light-chain kinase, a Ca2+/calmodulin-dependent enzyme, on preimplantation development of the mouse in an attempt to establish a regulatory role for this enzyme in preimplantation development. When late two-cell stage embryos were treated continuously with ML-9 or wortmannin at a concentration of 0, 1, 5, 10, or 15 microM, compaction and formation of the blastocyst were inhibited in a dose-dependent manner. Stage-specific treatment with ML-9 at 25 microM induced stage-specific responses of embryos after the eight-cell stage during the processes of compaction and cavitation. These morphological responses included aborted compaction, decompaction of compacted embryos, and the inability of embryos to form a cavity. These morphological effects were reversible, but, since cell proliferation was inhibited, the "recovered" embryos were small. Counting of cells on day 4 of culture, in both continuously treated and stage-specifically treated embryos, showed that the effect of ML-9 on cell proliferation was also dose-dependent. Wortmannin also had stage-specific effects at 15 microM, but these effects were irreversible and were more deleterious than those of ML-9. With neither inhibitor was there any apparent effect at the two-cell or the four-cell stage, although wortmannin inhibited cell division when applied stage-specifically at the four-cell stage. These results indicate that myosin light-chain kinase may be an important enzyme in the first steps of differentiation and in the maintenance of the differentiated state during preimplantation development of the mouse.
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Affiliation(s)
- N Kabir
- Department of Teratology and Genetics, Nagoya University, Japan
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32
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Sun XZ, Inouye M, Hayasaka S, Takagishi Y, Yamamura H. Effects of different doses of gamma-radiation on the developing brain of mice. Environ Med 1995; 39:113-6. [PMID: 12703527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
Morphogenetic changes in the developing brain induced by doses of 60Co gamma-irradiation ranging from 0 to 1.5 Gy on day 13 of pregnancy (E13) were studied in 6-week-old mice. Dose-related reductions in brain weight and cortical thickness (field 3 of Caviness) were significant for all irradiated groups, but abnormal cortical architecture was evident only in mice exposed to 1.0 and 1.5 Gy. Ectopic gray matter, enlarged lateral ventricles, and the absence of trunks from the corpus callosum were observed respectively in 23%, 30% and 10% of the mice exposed to 1.0 Gy, but these anomalies rose to 90%, 82% and 35% of the mice, respectively, when 1.5 Gy irradiation was applied. Brain malformations identical to the small heads and ectopic gray matter typically observed among atomic bomb survivors were reproduced in mice exposed to 1.5 Gy irradiation on E13.
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Affiliation(s)
- X Z Sun
- Department of Teratology and Genetics, Division of Molecular and Cellular Adaptation, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
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33
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Sun XZ, Inouye M, Hayasaka S, Takagishi Y, Yamamura H. Scanning microscopic evaluation on the development of the cerebral cortex in embryonic mouse subjected to gamma-irradiation. Environ Med 1995; 39:117-20. [PMID: 12703528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
Morphological events occurring in the developing cerebral hemispheres of mice exposed to a single dose of 60Co gamma-irradiation 1.5 Gy on embryonic day 13 (E13) were evaluated by scanning microscope. Twenty-four hr after the exposure, both cell debris and surviving cells had poured out into the ventricular lumen. Radial glial fibers were more crumpled than in the controls. By day E15, proliferating cells in different stages of the cell cycle appeared in the ventricular zone. The glial fibers formed a network through the brain mantle. By E17 many migrating cells attached to the disorderly glial fibers appeared in the different layers of the thin cerebral mantle. These findings suggest that development of the glial fibers was interrupted as early as 24 hr after the single exposure, meaning that irradiation on the developing brain may disrupt neuronal migration.
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Affiliation(s)
- X Z Sun
- Department of Teratology and Genetics, Division of Molecular and Cellular Adaptation, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
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Abstract
PURPOSE To establish the evaluating method for drug dissolution profiles in the gastrointestinal (GI) tract based on in vitro data for the enteric-coated multiple unit. METHODS Dissolution profile in the GI tract was calculated by the convolution procedure using an in vitro dissolution profile as a weighting function, and the gastric-emptying (GE) process as an input function (GE-convolution method). A computer program, GECONV, was developed for numerical execution of the convolution integral. RESULTS The in vivo dissolution profile of enteric-coated aspirin granules estimated by GE-convolution was in good agreement with the in vivo cumulative absorption profile calculated by the Wagner-Nelson method using the plasma concentration data after oral administration to healthy subjects. The in vitro/in vivo correlation improved markedly by taking the GE process into consideration. CONCLUSIONS These findings indicated that this convolution method is useful for estimating the in vivo dissolution profile of drugs, when they are administered in an enteric-coated multiple unit type dosage form, because the gastric emptying process is a determinant process for the in vivo drug dissolution.
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Affiliation(s)
- T Hayashi
- Developmental Research Laboratories, Shionogi & Co., Ltd., Hyogo, Japan
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Abstract
The action of benzyl alcohol (BA) as a major solvent of a liquid droplet dispersion ointment (LDDS), a preparation enabling excellent percutaneous absorption of drugs, was evaluated and compared with Azone and dimethyl sulfoxide (DMSO), which are known percutaneous absorption enhancers. Using a water sorption-desorption test, BA was found to increase hygroscopicity and decrease water-holding capacity to the same extent as Azone and DMSO. Differential scanning calorimetry (DSC) determination of the whole stratum corneum, and its lipids and proteins confirmed that BA and Azone act on the stratum corneum lipids while DMSO acts on its lipids and proteins. Furthermore, DSC and X-ray diffraction spectrum determinations of lipids in the stratum corneum suggest that the action of BA is moderate and reversible. The effect of BA may be one of the factors underlying the high percutaneous absorption found with LDDS.
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Affiliation(s)
- I Saitoh
- Developmental Research Laboratories, Shionogi & Co., Ltd., Hyogo, Japan
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Abstract
A liquid droplet dispersion ointment, LDDS, a formulation containing a drug solution as droplets in an oily vehicle, is excellent for percutaneous drug absorption. Bleeding of LDDS and in vitro drug release from LDDS were found to be enhanced by temperature increase. The influence of temperature on the physical properties of LDDS was studied using differential scanning calorimetry and X-ray diffraction spectroscopy. The liquid component content, possibly a hydrocarbon in the vehicle, increased with temperature; this may have been due to melting of the vehicle. In this liquid component, the drug concentration measured by HPLC increased with temperature. This change in the drug concentration may cause an increase in drug release, leading to the conclusion that, compared with conventional ointments, temperature has much greater effect on drug release from LDDS.
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Affiliation(s)
- I Saitoh
- Developmental Research Laboratories, Shionogi & Co., Ltd., Hyogo, Japan
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Nagata S, Takeshima K, Hirano K, Takagishi Y. [Pharmaceutical dosage form design of copoly (lactic/glycolic acid) microspheres. Mechanism of in vitro release of gentamicin]. YAKUGAKU ZASSHI 1994; 114:1005-14. [PMID: 7869233 DOI: 10.1248/yakushi1947.114.12_1005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The sustained release mechanism of gentamicin (GM) from lactic acid/glycolic acid copolymer (PLGA) microspheres was investigated. The terminal free carboxyl group of polymer was proved to be necessary for GM to be highly incorporated into microspheres by comparing interactions with GM and two types of polymers; free (ionized and non ionized) and the terminal esterified carboxyl group of polymer. The weight-average molecular weights (Mws) of component PLGAs of microspheres with an ionizable carboxyl group used here were approximately 4900 and 10000. The release pattern of GM was tested in phosphate buffered saline. The release rate of GM was dependent on the initial Mw and surface form. The GM release continued for 20 and 30 d from PLGA 4900- and PLGA10000-microspheres, respectively. The changes of total weight of microspheres tended to decrease with time, and the molecular weight distribution of PLGA gradually shifted to lower distribution, indicating a decrease in Mw. The changes and the shifts were dependent on the initial Mws of PLGAs but independent of their surface form. The half-times of wight loss of PLGA 4900- and PLGA10000-microspheres were about 10 and 20 d, respectively. From these results, the release profile of GM from PLGA microspheres was explained by the following three steps, i.e., 1) the release from the surface, 2) the relatively slow release caused by the obstruction of channels followed by the degradation of PLGA, 3) the release accompanied by the erosion of microspheres.
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Affiliation(s)
- S Nagata
- Shionogi Research Laboratories, Shionogi & Co., Ltd., Osaka, Japan
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38
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Borodin PM, Inouye M, Oda S, Ikushima T, Takagishi Y, Yamamura H. Radioadaptive response in primary mouse spermatocytes revealed by analysis of synaptonemal complexes. Mutat Res 1994; 310:151-6. [PMID: 7523880 DOI: 10.1016/0027-5107(94)90019-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
This study was aimed at estimating the damage to the synaptonemal complex (SC) of male mice caused by radiation exposure at the ultimate pre-meiotic interphase. Four experimental groups were formed: group 1 was an untreated control, group 2 received a low dose (50 mGy) of radiation, group 3 a high dose (4 Gy) of radiation, group 4 was first treated with a low dose (50 mGy) and 4 h later with a high dose (4 Gy). Mice were killed 4 days after the treatment. Early pachytene cells were selected for the electron microscopic analysis of SCs. These cells were supposed to be at pre-meiotic interphase at the time of irradiation. Treatment with a low dose of radiation did not produce any substantial increase in the frequency of SC aberrations, while exposure to the high dose resulted in various types of damage. Group 4 demonstrated significantly lower frequencies of axial breaks/fragments and multiaxial configurations than group 3. At the same time, these two groups did not differ in the frequencies of inter- and intrachromosomal exchanges such as translocations, inversions, and deletions. We suppose that the number of breaks produced by a high dose of radiation was the same in the both groups. However, a proportion of the breaks that remained unrepaired until pachytene and were expressed as gaps, fragments, and multiaxial configurations was reduced by pretreatment with the low dose of radiation.
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Affiliation(s)
- P M Borodin
- Institute of Cytology and Genetics, Novosibirsk, Russia
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Abstract
The partition of mepitiostane, testosterone, and some structurally related compounds between lymph and blood in rat jejunum (lymph-blood partition ratio; LBPR) was determined, and the quantitative relationship between LBPR and lipophilicity was examined. When the delta Rm values (hydrophobic parameter derived from the mobility) relative to testosterone were < 0.2, their logLBPRs remained approximately constant in the range of -2 to -3. When the delta Rm values of the compounds were > 0.2, a linear correlation (r = 0.986, n = 8) was observed between these values and the logLBPRs. The LBPR, but not the extent of lymphatic absorption, of lipophilic molecules was determined strictly by the superlipophilicity, and for high partitioning into the lymph (> 50% of the absorbed amount), the delta Rm value had to be > 0.50 (5.65 as the logP value). The relationship between LBPR and superlipophilicity could be explained on the basis of the theoretical equations derived from absorption kinetics based on a dynamic partitioning model.
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Affiliation(s)
- T Ichihashi
- Shionogi Research Laboratories, Shionogi & Co., Ltd., Osaka, Japan
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Masuda K, Hirano K, Takagishi Y. Use of blue-sepharose for purification of immunotoxin containing type 1 ribosome-inactivating protein, gelonin. Biomed Chromatogr 1994; 8:9-13. [PMID: 7510554 DOI: 10.1002/bmc.1130080103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
This paper describes a method suitable for purifying immunotoxin containing type 1 ribosome-inactivating protein, gelonin. The separation of free (unreacted) 80G, a monoclonal antibody against alpha-fetoprotein (AFP), from semipurified 80G-gelonin conjugate was unsuccessful by conventional CM-Sepharose ion-exchange chromatography because the isoelectric point of the conjugate did not increase enough to reach that of gelonin alone. In contrast, Blue Sepharose affinity chromatography could efficiently separate free 80G from the semipurified conjugate because the conjugate was bound to the column by its gelonin moiety while free 80G was not in buffer containing NaCl of a particular concentration range. However, a small amount of conjugate containing gelonin modified with N-succinimidyl 3-(2-pyridyldithio)propionate, but not with 2-iminothiolane, could not bind to the column. The conjugate purified by the use of Blue Sepharose showed selective cytotoxicity against AFP-producing human hepatoma cells.
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Affiliation(s)
- K Masuda
- Shionogi Research Laboratories, Shionogi & Co., Ltd., Osaka, Japan
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Takagishi Y, Yamamura H. Membrane structure of parallel-fibre synaptic terminals in the cerebellum of the jaundiced Gunn rat: freeze-fracture and E-PTA study. J Neurocytol 1994; 23:39-48. [PMID: 8176417 DOI: 10.1007/bf01189815] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Parallel-fibre synaptic membranes were examined by freeze-fracture and ethanolic-phosphotungstic acid methods in the cerebellum of homozygous (j/j) Gunn rats with hereditary jaundice. Parallel-fibre synapses with dendritic spines of Purkinje cell were severely affected since many Purkinje cells degenerated during the early postnatal period. Some parallel-fibre synaptic terminals lacked their postsynaptic partners and faced astrocytic processes from 18 days of age to the adult stage. These parallel-fibre terminals contained clusters of synaptic vesicles adjacent to synaptic membranes, and synaptic membranes and synaptic cleft materials were identical to those of parallel fibres with postsynaptic partners, as visualized by conventional electron microscopy with osmium tetroxide postfixation and staining of sections with uranyl acetate and lead citrate. In freeze-fractured specimens, the presynaptic membrane of parallel fibres had diffusely distributed large particles and tiny pits on the P-face and protuberances on the E-face, together representing synaptic vesicle attachment sites. Such vesicle attachment sites were present on the presynaptic membranes of parallel fibres without postsynaptic partners from day 18 to the adult stage. After ethanolic-phosphotungstic acid staining, parallel-fibre terminals displayed presynaptic dense projections, intercleft materials and postsynaptic thickening, but some parallel fibres lacked postsynaptic thickening. These observations suggest that the presynaptic membrane structure of the parallel fibre is preserved, even in the absence of a postsynaptic partner, in j/j cerebella. A mechanism for persistence of presynaptic membrane structures without postsynaptic partners in j/j cerebella is discussed.
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Affiliation(s)
- Y Takagishi
- Research Institute of Environmental Medicine, Nagoya University, Japan
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Masuda K, Takahashi K, Hirano K, Takagishi Y. Selective antitumor effect of thioether-linked immunotoxins composed of gelonin and monoclonal antibody to alpha-fetoprotein or its F(ab')2 fragment. Tumour Biol 1994; 15:175-83. [PMID: 7521059 DOI: 10.1159/000217889] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Two thioether-linked conjugates composed of monoclonal antibody (MoAb) to alpha-fetoprotein (AFP), 80G or its F(ab')2 fragment, and a type 1 ribosome-inactivating protein (RIP), gelonin, were prepared as potent immunotoxins [80G-CS-GL(IT) and F(ab')2-CS-GL(IT)]. Each conjugate contained one gelonin per 80G or its F(ab')2 fragment. The binding activity of these conjugates was as high as that of intact 80G or F(ab')2. The in vitro cytotoxic effect of F(ab')2-CS-GL(IT) on AFP-producing HuH-7 cells was approximately 100-fold more potent than that of 80G-CS-GL(IT). Also, F(ab')2-CS-GL(IT) showed slight cytotoxicity against non-AFP-producing HuH-13 cells, while 80G-CS-GL(IT) did not. On the other hand, both conjugates had similar selective antitumor activity against HuH-7N cells in nude mice, possibly due to their similar distribution in the tumor. The results suggest that our MoAb 80G is a suitable carrier for delivering type 1 RIP such as gelonin into AFP-producing hepatoma cells and that its F(ab')2 fragmentation does not enhance targeting efficiency.
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Affiliation(s)
- K Masuda
- Shionogi Research Laboratories, Shionogi & Co., Ltd., Osaka, Japan
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Borodin PM, Oda S, Takagishi Y, Inouye M, Yamamura H. Meiotic Prophase in the Fetal Ovary of the House Musk Shrew, Suncus murinus. CYTOLOGIA 1994. [DOI: 10.1508/cytologia.59.465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- P. M. Borodin
- Institute of Cytology and Genetics, Russian Academy of Sciences
| | - S. Oda
- Laboratory of Animal Management, School of Agricultural Sciences Nagoya University
| | - Y. Takagishi
- Research Institute of Environmental Medicine, Nagoya University
| | - M. Inouye
- Research Institute of Environmental Medicine, Nagoya University
| | - H. Yamamura
- Research Institute of Environmental Medicine, Nagoya University
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Masuda K, Takahashi K, Nagata S, Hirano K, Takagishi Y. Immunotoxins composed of monoclonal antibody to alpha-fetoprotein and gelonin as a potent hepatoma-targeted drug delivery system. J Drug Target 1994; 2:323-31. [PMID: 7532086 DOI: 10.3109/10611869409015913] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
This study was carried out to evaluate our monoclonal antibody (MoAb) to alpha-fetoprotein (AFP), 80G, as a carrier for targeting AFP-producing hepatoma. Pharmacokinetic analysis showed that the MoAb 80G was actively incorporated into AFP-producing HuH-7N cells (xenograft of human hepatoma cell line, HuH-7) in nude mice. Four conjugates composed of MoAb 80G, and a type 1 ribosome-inactivating protein, gelonin, were prepared. They involve two disulfide-linked and two thioether-linked conjugates. The binding activity of conjugates against AFP remained as high as that of intact 80G according to enzyme-linked immunosorbent assay. The in vitro cytotoxic effects of all the conjugates were specific against AFP-producing HuH-7 cells. Of these conjugates, two containing gelonin modified with 2-iminothiolane were more potent than the others. They showed significant antitumor activity upon AFP-producing HuH-7N cells in nude mice. However, the disulfide conjugate was more toxic to mice than the thioether conjugate judging from the loss in body weight and the liver damage. These results suggest that our MoAb 80G is a suitable carrier for targeting AFP-producing hepatoma cells, and that the noncleavable thioether conjugate is promising as an AFP-producing hepatoma-targeted drug delivery system.
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MESH Headings
- Animals
- Antibodies, Monoclonal/administration & dosage
- Antibodies, Monoclonal/metabolism
- Antibodies, Monoclonal/pharmacokinetics
- Antibodies, Monoclonal/toxicity
- Aspartate Aminotransferases/blood
- Biological Availability
- Body Weight/drug effects
- Creatinine/blood
- Cytotoxicity Tests, Immunologic
- Disease Models, Animal
- Drug Carriers
- Drug Delivery Systems
- Electrophoresis, Polyacrylamide Gel
- Enzyme-Linked Immunosorbent Assay
- Liver/drug effects
- Liver Neoplasms, Experimental/drug therapy
- Liver Neoplasms, Experimental/metabolism
- Mice
- Mice, Nude
- Molecular Weight
- Plant Proteins/administration & dosage
- Plant Proteins/metabolism
- Plant Proteins/pharmacokinetics
- Plant Proteins/toxicity
- Protein Synthesis Inhibitors/administration & dosage
- Protein Synthesis Inhibitors/metabolism
- Protein Synthesis Inhibitors/pharmacokinetics
- Protein Synthesis Inhibitors/toxicity
- Ribosome Inactivating Proteins, Type 1
- Structure-Activity Relationship
- Tissue Distribution
- Tumor Cells, Cultured
- alpha-Fetoproteins/immunology
- alpha-Fetoproteins/metabolism
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Affiliation(s)
- K Masuda
- Shionogi Research Laboratories, Shionogi & Co., Ltd., Osaka, Japan
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Borodin PM, Oda S, Takagishi Y, Inouye M, Yamamura H. Chromosome Pairing and Nucleolar Morphology in the Male House Musk Shrew, Suncus murinus. CYTOLOGIA 1994. [DOI: 10.1508/cytologia.59.461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- P. M. Borodin
- Institute of Cytology and Genetics, Russian Academy of Sciences
| | - S. Oda
- Laboratory of Animal Management, School of Agricultural Sciences Nagoya University
| | - Y. Takagishi
- Research Institute of Environmental Medicine, Nagoya University
| | - M. Inouye
- Research Institute of Environmental Medicine, Nagoya University
| | - H. Yamamura
- Research Institute of Environmental Medicine, Nagoya University
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Masuda K, Nagata S, Hirano K, Takagishi Y, Hirai H. Elevated serum alpha-fetoprotein level of nude mice bearing hepatoma cells by treatment with monoclonal antibodies to alpha-fetoprotein. Biochim Biophys Acta 1993; 1182:128-32. [PMID: 7689341 DOI: 10.1016/0925-4439(93)90132-k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
This study was carried out to clarify the reason for elevation of serum alpha-fetoprotein (AFP) level of nude mice bearing hepatoma cells after treatment with monoclonal antibodies (MoAbs) to AFP. MoAbs to AFP showed no effect on the cumulative amounts of AFP secreted from human hepatoma cell line, HuH-7, in vitro. However, the treatment of nude mice bearing HuH-7N cells (HuH-7 xenograft) with MoAbs to AFP led to elevation of the serum AFP level in spite of the fact that the growth curve of HuH-7N cells was similar to that for PBS treatment. This apparent elevation of the serum AFP level is thought to be due to the slow elimination of AFP-MoAb immune complexes with little lattice structure from circulation, but not the enhancement of AFP secretion of HuH-7N cells. Thus, when using a MoAb alone or MoAb-drug conjugate, the serum AFP level should only be cautiously used as a tumor marker for evaluating the targeting immunotherapy.
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Affiliation(s)
- K Masuda
- Shionogi Research Laboratories, Shionogi & Co., Ltd., Osaka, Japan
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Abstract
The development of granule cells and the formation of synapses with mossy fibres were investigated in cerebella from jaundiced (j/j) Gunn rats with hereditary hyperbilirubinemia. The external granular layer was thinner than that in cerebella from heterozygous (+/j) Gunn rats without hyperbilirubinemia on days 12 and 15 after birth, and it had disappeared in places by day 18. Migrating granule cells decreased in number from days 12 to 18. In the internal granular layer, the paucity of granule cells became apparent on day 12 and a reduction in the number of cells was prominent from day 18 onward. More degenerating cells were found in j/j cerebella than in +/j cerebella on days 12 and 15. Mossy fibre-granule cell synapses (glomeruli) were immature in appearance in j/j and +/j cerebella from days 7 to 12; small, roundish mossy fibre terminals were in contact with a few dendrites of granule cells. After day 18, the glomeruli were mature in terms of shape in +/j cerebella. By contrast, the mossy terminals remained small and roundish, and the granule cell dendrites that surrounded the mossy terminals did not increase in number nor develop digitiform branches in j/j cerebella. The mossy terminals were partially surrounded by glial processes and were occasionally surrounded by large dendrites of Golgi cells, which made multiple synaptic contacts. Some degenerating mossy terminals were present from days 18 to 30. These anomalous glomeruli may be caused by insufficient synaptic contacts with granule cells.
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Affiliation(s)
- Y Takagishi
- Research Institute of Environmental Medicine, Nagoya University, Japan
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Yamamura H, Takagishi Y. Cerebellar hypoplasia in the hyperbilirubinemic Gunn rat: morphological aspects. Nagoya J Med Sci 1993; 55:11-21. [PMID: 8247099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Gunn rats, a mutant strain of rats, suffer from autosomal recessive hyperbilirubinemia. The homozygotes (j/j) develop jaundice soon after birth and often exhibit kernicterus and cerebellar hypoplasia that are due to bilirubin. Therefore, j/j Gunn rats have been used as an animal model of bilirubin encephalopathy, as well as of neonatal hyperbilirubinemia. In this review, we discuss morphological aspects of the cerebellar hypoplasia that is due to bilirubin and describe the relationship between plasma bilirubin levels and cerebellar hypoplasia, as well as the pathogenesis of cerebellar hypoplasia, including abnormal histogenesis of the cerebellar cortex, abnormalities associated with Purkinje cells and abnormal synaptogenesis in j/j Gunn rats.
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Affiliation(s)
- H Yamamura
- Department of Teratology and Genetics, Nagoya University, Japan
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Masuda K, Nagata S, Hirano K, Takagishi Y, Hirai H. Cytotoxicity induced by monoclonal antibody to alpha-fetoprotein coadministered with spleen cells of nude mice. Microbiol Immunol 1993; 37:165-7. [PMID: 7684811 DOI: 10.1111/j.1348-0421.1993.tb03195.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
This paper describes an attempt to effectively induce antibody-dependent cell-mediated cytotoxicity (ADCC) in nude mice. A monoclonal antibody against alpha-fetoprotein, 80G, coadministered with spleen cells from other nude mice bearing HuH-7N (xenograft of human hepatoma cell line, HuH-7) significantly suppressed the growth of HuH-7N as compared to treatment with 80G alone. 80G with spleen cells from normal nude mice also had some suppressive effect. In contrast, no effect was observed with each spleen cells alone as well as 80G alone. These results suggest that further supply of effector cells could enhance ADCC activity in nude mice.
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Affiliation(s)
- K Masuda
- Shionogi Research Laboratories, Shionogi & Co., Ltd., Osaka, Japan
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50
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Abstract
Substitution of the steroid epitiostanol (EP) at position 17 with methoxycyclopentane yields the extremely liophilic mepitiostane (MP) with preferential partitioning into the lymph. Most of the MP in the lymph was associated with the core lipids of chylomicrons and very low-density lipoproteins (VLDL), as was also the case for EP. However, the dialysis velocity of EP and MP from lymph to plasma differed greatly; EP, but not MP, was transferred from the lymph to the plasma. This difference was attributed to differences in their unbound fraction in the lymph. Lymphatic transfer and the logP value of several tested steroids correlated well. Therefore, the oral EP prodrug, MP, partitioned into the lymph because of its superlipophilicity and resultant retention in the core lipids of chylomicrons and VLDL.
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Affiliation(s)
- T Ichihashi
- Shionogi Research Laboratories, Shionogi & Co., Ltd., Osaka, Japan
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