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Nishida M, Ogata K, Sakurai H, Morimoto A, Yamashita K, Kawada J. A binding profile of manganese to the nucleus of rat liver cells, and manganese-induced aberrations in thyroid hormone content and RNA synthesis in the nucleus. BIOCHEMISTRY INTERNATIONAL 1992; 27:209-19. [PMID: 1380236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Manganese (Mn) is accumulated in the nuclear and mitochondrial fractions when excess Mn is administered. However, little is known with respect to the behaviors of Mn in nuclei. In the present study, rats were given excess Mn and the nuclei were purified from liver cells by differential and sucrose gradient centrifugations. Being subjected to equilibrium dialysis with a radioactive 54Mn, the binding capacity of Mn in nuclei from the control rat was five-fold higher than BSA, which was used as a reference protein; and the capacity of 54Mn-binding rose in the nuclei from the Mn-treated animals in comparison with those from the control. On the analyses of nuclear materials with partial solubilization, sepharose column chromatography and HPLC, there were two major fractions which associated with a lot of Mn; one fraction was of large molecules of DNA, and the other fraction seemed to be peptides with small molecular weights. Therefore, Mn may open up a superhelical structure of DNA to provide more negatively charged phosphate moiety as a binding-site for a positively charged Mn. The results also disclosed a possible aberration in biological functions due to excess Mn in nuclei; the apparent association constant of triiodothyronine, a physiologically active thyroid hormone, to the nucleus was reduced by 75% and the uptake of 14C-labelled orotic acid to a newly synthesized RNA in the liver was severely inhibited.
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Nishida M, Kawada J. Hormonal control of manganese transport in the mouse thyroid. EXPERIENTIA 1992; 48:262-5. [PMID: 1547856 DOI: 10.1007/bf01930470] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The present study deals with a possible mechanism controlling the transport of manganese (Mn), an essential trace element, from the circulation to the thyroid. Mice were pretreated with propylthiouracil (PTU) or triiodothyronine (T3), and a measurement of the thyroid:serum concentration ratio (T/S) of radioactive manganese (54Mn) was carried out. The T/S of 54Mn was greatly enhanced by PTU, but reduced by T3. Several methods were used to demonstrate that the T/S of 54Mn depends upon the level of thyroid-stimulating hormone (TSH) in the serum. First, bovine TSH was injected into mice; an increase in the T/S resulted. Secondly, serum thyroxine and T3 levels measured by radioimmunoassay (RIA) suggested that PTU produced an increase in serum TSH and T3 a decrease. However, direct measurement of mouse TSH by RIA for rat TSH failed to produce proof of any changes in TSH level, owing to poor cross-reactivity. Taking all the information into account, it is concluded that Mn-transport into the thyroid is controlled by the thyroid state.
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Yoshimura Y, Kondo K, Nishida M, Kawada J, Tanaka R. Characterization of thyroidal membrane-bound Mg-adenosinetriphosphatase activated by trypsin or poly-L-lysine. Chem Pharm Bull (Tokyo) 1992; 40:423-6. [PMID: 1535027 DOI: 10.1248/cpb.40.423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The Mg-adenosinetriphosphatase (ATPase) in the thyroidal NaI-treated microsome fraction was activated by treatment with basic polyamino acids or trypsin, but not with acidic polyamino acids and basic proteins such as lysozyme and ribonuclease. The enzyme kinetics showed that the activation of trypsin or poly-L-lysine was due to an increase in the maximal velocity of the hydrolyzing reaction without a change in the affinity of the enzyme for its substrate. A break at about 25 degrees C was observed in the Arrhenius plots of Mg-ATPase in the trypsin- or poly-L-lysine treated preparations, but there was no break in the control preparation. These results suggest that the activating effect of trypsin or poly-L-lysine on Mg-ATPase activity in the thyroidal NaI-treated microsome fraction is related to the lipid environment surrounding the enzyme molecule in the thyroid cell membrane.
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Nishida M, Sasaki T, Terada H, Kawada J. Synergistic and antagonistic effects on fatty acid composition in the liver mitochondria of rats by thyroidectomy and streptozotocin-administration. RESEARCH COMMUNICATIONS IN CHEMICAL PATHOLOGY AND PHARMACOLOGY 1991; 74:317-26. [PMID: 1837932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The content of individual fatty acid component in mitochondria of livers from thyroidectomized (Tx) and streptozotocin (STZ)-induced diabetic rats was measured to investigate how different hormones are interrelated to control the amount of a particular fatty acid in mitochondria. The results showed (1) diabetes, in general, affected fatty acid contents more severely than hypothyroidism, regardless of the direction of the changes; (2) Hypothyroidism and diabetes affected antagonistically the contents of C16 species and C18:1, which belong to a de novo synthesis (oleate series). However, the two pathological conditions affected synergistically those of higher unsaturated species, eg. C18:2, C20:3 and C20:4, which belong to a dietary-dependent synthesis (linoleate series). These results strongly indicated that each desaturation site and elongation site is affected in a preferential order by either thyroid hormone or insulin, and that hypothyroidism and diabetes have their effects differently on the process of de novo synthesis and the pathways initiated from an essential fatty acid in mitochondria.
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Nishida M, Kumamoto T, Yano S, Yamaguchi T, Otsuka M, Kawada J. Unusually high levels of thyroid hormones in isolated and/or monolayer-cultured pig thyroid epithelial cells. THE SCIENCE OF NATURE - NATURWISSENSCHAFTEN 1991; 78:509-11. [PMID: 1758497 DOI: 10.1007/bf01131400] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Ishizuka H, Nishida M, Kawada J. Changes in stainability observed by light microscopy in the brains of ataxial mice subjected to three generations of manganese administration. BIOCHEMISTRY INTERNATIONAL 1991; 25:677-87. [PMID: 1726132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Two neonates of mice which manifested abnormal motions in their gait in the third generation litter, following the start of manganese (Mn) administration, were selected. One was severely affected by Mn and the other was only moderately affected. Various regions in the brains of the neonates were subjected to histochemical examination under a light microscopy. The losses of stainability in granular cells in the external layer of the cerebral cortex, and Purkinje cells in the cerebellar cortex, and the increase in stainability of the nerve fibers in the cerebellar medulla were in parallel to the degree of abnormal movement in the gait; the greater loss or gain in stainability, varying according to the regions, was associated with the more severe damages to motion. Meanwhile, the changes in the stainabilities of nerve cell nuclei in the lamellar structure of cerebral motor areas and the Nissl bodies in the cerebral medulla were already maximal in the moderately affected neonate. These results indicate that the Mn effect covers a broad area of the extrapyramidal tract even though there are some differences in the sensitivity to Mn in different regions.
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Sofue M, Yoshimura Y, Nishida M, Kawada J. Uptake of nicotinamide by rat pancreatic beta cells with regard to streptozotocin action. J Endocrinol 1991; 131:135-8. [PMID: 1836006 DOI: 10.1677/joe.0.1310135] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Exposure of rat pancreatic beta cells in monolayer culture to 2 mmol streptozotocin (STZ)/l for 1 h followed by thorough washing inhibited their uptake of [14C]nicotinamide and [3H]2-deoxyglucose [( 3H]2-DG) to about 50% and also reduced the intracellular ATP concentration to 50% of that in control cells. These changes were not due to a lethal cytotoxic effect of STZ, because cell viability, as estimated by succinic dehydrogenase activity, was 90% of that of control cells. Oligomycin and carbonylcyanide-m-chlorophenylhydrazone (CCCP), an uncoupler of oxidative phosphorylation, caused a dose-dependent decrease in intracellular ATP concentration while maintaining high cell viability. These ATP-depleted cells showed a decrease in insulin release and an inhibition of the uptake of [14C]nicotinamide and [3H]2-DG in a dose-dependent manner. Therefore oligomycin and CCCP reproduced the same effects as those found in beta cells treated with STZ. These results suggest that the uptake of nicotinamide and 2-DG by beta cells might be regulated by their intracellular ATP concentration. The decreased uptake of nicotinamide in ATP-depleted beta cells caused by STZ might explain the lack of protective effect of nicotinamide against STZ cytotoxicity when administered after the latter. Furthermore, the radiotracer experiments demonstrated that the transport of nicotinamide by intact beta cells was inhibited in a dose-dependent manner by 2-DG and vice versa, i.e. the transport of 2-DG was inhibited by nicotinamide. These findings suggest the existence of a common transport mechanism in beta cells responsible for the uptake of nicotinamide and 2-DG, the transport of which is known to occur by facilitated diffusion.
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Hirose G, Kawada J, Tsukada K, Yoshioka A, Sharpe JA. Upbeat nystagmus: clinicopathological and pathophysiological considerations. J Neurol Sci 1991; 105:159-67. [PMID: 1757792 DOI: 10.1016/0022-510x(91)90140-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We describe an electro-oculographic study of upbeat nystagmus in 4 patients, with neuropathological correlation in one. All patients had lesions in the pontine tegmentum. The electro-oculographic data may be explained by imbalanced vertical vestibular or smooth pursuit eye movement control. The nystagmus stopped or reversed direction during convergence or in supine head positions. We propose that changes in the intensity or direction of upbeat nystagmus that are induced by convergence or changes in head position, are caused by vertical imbalance in the otolithic-ocular reflex, when superimposed on an imbalanced vestibulo-ocular reflex (VOR). Imbalance of the otolithic-ocular reflex and the vertical VOR are caused by damage in the pontomedullary tegmentum.
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Nishida M, Sasaki T, Terada H, Kawada J. Differential effects on fatty acid compositions in the liver microsomes of thyroidectomized or streptozocin induced diabetic rats. Chem Pharm Bull (Tokyo) 1991; 39:2382-6. [PMID: 1804552 DOI: 10.1248/cpb.39.2382] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The purpose of the present study was to locate a controversial site and to make generalizations about the effects of thyroidectomy (Tx) and streptozocin (STZ) on the distribution pattern of an individual fatty acid in microsomal fractions of the animals thus treated. The results obtained were compared with the reported data. The effects of Tx on C18:1, C18:2, and all detectable C20 and C22 species harmonized well within each species; however the effects of Tx on C16 species and C18:0 varied within each species. Meanwhile, all the effects of STZ were identical within the species, but were often in opposite directions between two adjacent species; e.g. C18:0 and C18:1. These findings strongly indicate that desaturation and elongation sites were independently affected by either Tx or STZ. The comparison suggested that controversial effects appeared in the distribution proper to species C18. Therefore, delta 9-desaturase activity in the microsomal fractions was measured, using stearoyl coenzyme A (CoA) as substrate, resulting in some partial reduction in Tx, but complete suppression in STZ-treated animals. The total contents of phospholipid and cholesterol in the microsomes were also measured. Results showed a significant increase in microsomes within the STZ-group, but almost no change in the Tx-group, indicating that the changes in an individual fatty acid component and in the total fatty acids do not always take place in parallel.
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Yamashita K, Horisaka Y, Okamoto Y, Yoshimura Y, Matsumoto N, Kawada J, Takagi T. Architecture of implanted bone matrix gelatin influences heterotopic calcification and new bone formation. PROCEEDINGS OF THE SOCIETY FOR EXPERIMENTAL BIOLOGY AND MEDICINE. SOCIETY FOR EXPERIMENTAL BIOLOGY AND MEDICINE (NEW YORK, N.Y.) 1991; 197:342-7. [PMID: 2068127 DOI: 10.3181/00379727-197-43241] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Heterotopic bone formation in skeletal muscle induced by compacted demineralized bone matrix gelatin (BMG) was studied histologically and biochemically. BMG was obtained by dehydrating diaphyseal shafts of femora and tibiae of 4-week-old male Sprague-Dawley rats, cutting the bone into chips, and demineralizing and extracting the chips with various solutions. The BMG was treated with 4 M guanidine-HCl, and compacted BMG was prepared by centrifugation. The compacted BMG was implanted into the rectus abdominis muscle of 5-week-old male Sprague-Dawley rats. The resulting specimens were examined histologically, and their alkaline phosphatase activity and the calcium content of the tissues were measured 3, 5, 7, 10, and 15 days after implantation. The BMG (separated BMG) with 75- to 500-microns particle sizes were implanted into control rats. The results showed that calcification, alkaline phosphatase activity, and bone formation were suppressed by implantation of the compacted BMG and that scarcely any vascularization occurred. Calcification, vascularization, and alkaline phosphatase activity were related and were indispensable for bone formation. In the control group, bone formation was observed at sites of high activity of alkaline phosphatase and well-developed vascularization. These results suggested that compacting of BMG suppressed vascularization, decreased calcification, and consequently reduced the induction of bone formation.
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Horisaka Y, Okamoto Y, Matsumoto N, Yoshimura Y, Kawada J, Yamashita K, Takagi T. Subperiosteal implantation of bone morphogenetic protein adsorbed to hydroxyapatite. Clin Orthop Relat Res 1991:303-12. [PMID: 2060223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Bone development was induced by bone morphogenetic protein (BMP) adsorbed to hydroxyapatite (HAP) under the periosteum of rat parietal bone. The BMP was isolated by Sephacryl-S200 column chromatography after passage through a membrane filter system. The yield of the fraction with BMP activity was 20 times greater than yields obtained by conventional methods. BMP was adsorbed to HAP in vacuo. HAP alone was implanted as a control. The formation of cartilage and bone was observed seven days after the implantation of BMP-HAP, and the newly formed bone fused with the host calvaria after 28 days. In control rats, no bone formation was seen within 56 days after implantation. The BMP-HAP complex was more effective in induced periosteal bone formation than HAP only.
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Okamoto Y, Horisaka Y, Matsumoto N, Yoshimura Y, Kawada J, Yamashita K, Takagi T. Muscle tissue reactions to implantation of bone matrix gelatin. Clin Orthop Relat Res 1991:242-53. [PMID: 1993382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Histologic changes of muscle tissue in the early stage of heterotopic osteogenesis induced by syngeneic insoluble bone matrix gelatin (BMG) with bone morphogenetic protein in rats was observed by light and electron microscopy. BMG induced cartilage in muscle tissue by Day 7 after its implantation, woven bone by Day 10, and lamellar bone with bone marrow by Day 14. The new findings in this work include (1) the disappearance of the basement membrane of muscle fibers; (2) the activation of the satellite cells of muscle fibers; (3) the appearance of fibroblastlike cells that closely resembled activated satellite cells among the degenerated muscle fibers or on the surface of the BMG; and (4) the change of fibroblastlike cells to chondroblasts or osteoblasts. These findings suggest that intramuscular implantation of BMG caused the conspicuous disappearance of the basement membrane of the muscle fiber and may play a part in osteogenesis induced by BMG.
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Yamashita K, Horisaka Y, Okamoto Y, Yoshimura Y, Matsumoto N, Kawada J, Takagi T. Effect of bupivacaine on muscle tissues and new bone formation induced by demineralized bone matrix gelatin. ACTA ANATOMICA 1991; 141:1-7. [PMID: 1835237 DOI: 10.1159/000147090] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Heterotopic bone formation induced by demineralized bone matrix gelatin (BMG) in bupivacaine-HCl-treated skeletal muscle was examined histologically. BMG was obtained by dehydrating diaphyseal shafts of femora and tibiae of male, 4-week-old Sprague-Dawley (SD) rats, cutting it into chips, and demineralizing and extracting the chips with various solutions. The BMG was implanted into the rectus abdominis muscle of male, 5-week-old SD rats, bupivacaine-HCl was injected at the same site, and the resulting plaques of tissues were examined histologically on days 5, 10, 15 and 20 after BMG implantation. Heterotopic bone formation occurred in all animals. The bupivacaine-treated group had more degenerated and injured muscle fibers, and more osteocytes than the control group. Electron microscopy showed that the basement membrane of muscle fibers was discontinuous and that many mononucleated cells resembling activated satellite cells were present on day 5. Many fibroblasts, undifferentiated mesenchymal cells and myogenic cells were seen in the area around the BMG. In new bones there were few osteocytes on day 10, but their numbers were increased on days 15 and 20 after implantation, especially in the bupivacaine-treated group. The population of osteocytes that increased rapidly may have included mononucleated cells similar to activated satellite cells.
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Hirose G, Kawada J, Tsukada K, Komatsuzaki A, Sharpe JA. Primary position upbeat nystagmus. Clinicopathologic study of four patients. ACTA OTO-LARYNGOLOGICA. SUPPLEMENTUM 1991; 481:357-60. [PMID: 1927416 DOI: 10.3109/00016489109131421] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We report an electro-oculographic study (EOG) of upbeat nystagmus and neuroradiological correlations in 4 patients and neuropathological findings in 1 patient. All 4 patients revealed responsible lesions in the lower pontine tegmentum. The EOG data suggest that our patients had a deficit in vertical smooth eye movement balance. The nystagmus stopped or reversed direction during convergence or changes of head position. These EOG findings might be caused by vertical imbalance in the otolithic ocular reflex, superimposed on an imbalanced vestibulo-ocular reflex (VOR), secondary to a damage to the pontomedullary tegmentum.
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Nishida M, Yakushiji H, Kawada J, Sakurai H, Takada J. Changes in mouse brain monoamine oxidase activity in the first, second and fourth generations after manganese administration. BIOCHEMISTRY INTERNATIONAL 1991; 23:307-15. [PMID: 1859434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The present study was conducted to explore whether or not manganese effect on brain monoamine oxidase (EC 1.4.3.4) is subject to hereditary genetic amplification. Mice of both sexes were given manganese through four generations, and the enzyme activity was measured in the cerebral cortex, cerebellum, hypothalamus and hippocampus of each of the generations except for the third, whose activity we were not in a position to measure. Intrinsic enzyme activity was highest in the cerebellum, and was followed by those in the cerebral cortex and hypothalamus. The activity in the hippocampus was the lowest. Manganese administration greatly stimulated the activity in the cerebellum. However, as generation succeeded, the level of susceptibility to manganese gradually declined. Manganese concentration in pooled suborgan fractions proved to be, in every case, higher in the cerebral cortex, cerebellum and hippocampus and lower in the hypothalamus. No indication was found that the manganese effect is genetically inherited.
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Nishida M, Yoshimura Y, Kawada J, Ookubo A, Kagawa T, Ikawa A, Hashimura Y, Suzuki T. Phosphate and pepsin adsorptions by a new boehmite compound and aluminum hydroxide. BIOCHEMISTRY INTERNATIONAL 1990; 22:913-20. [PMID: 2099151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A new microcrystalline compound of aluminum oxide hydroxide (tentatively named PT-A) was synthesized in the hope of providing a better phosphate adsorbent for future clinical use than the currently marketed aluminum hydroxide gels (ALG). An X-ray diffraction study demonstrated a boehmite structure in PT-A but an amorphous structure in ALG. PT-A was more stable in pH change than ALG; in elution tests in artificial gastric and intestinal solutions, aluminum ion eluted from PT-A was maximally 10% of the amount from ALG at pH 1.2; and was undetectable at pH 6.8, at which point ALG still showed some aluminum elution. Phosphate-adsorbing efficacy of PT-A and ALG in vitro was about the same at pH 1.2; however, it was four times greater in PT-A than in ALG at pH 6.8, indicating that PT-A will be effective in the intestine. PT-A also adsorbed pepsin but the amount was at most the same or much less than that adsorbed by ALG, which depended on pH in solution.
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Nishida M, Sato K, Kawada J. Differential effects of methylmercuric chloride and mercuric chloride on oxidation and iodination reactions catalyzed by thyroid peroxidase. BIOCHEMISTRY INTERNATIONAL 1990; 22:369-78. [PMID: 2090100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Thyroid peroxidase (TPO), the major enzyme in the thyroid hormone synthesis, multifunctionally catalyzes (1) iodide oxidation, (2) iodination of the precursor protein, and (3) a coupling reaction of iodotyrosyl residues. The present study was carried out to examine the mercurial effects on the iodination, the second step of TPO. Purified porcine thyroglobulin or bovine serum albumin as acceptor protein was iodinated with [125I]NaI and H2O2 by purified porcine TPO. Iodinated protein was separated by acid precipitation on membrane filter or paper chromatography. Both CH3HgCl and HgCl2 dose-dependently inhibited the iodination, but HgCl2 was more potent to inhibit the iodination than CH3HgCl. These mercurial effects on the second step resemble the effects on the third step which were already reported; but are in marked contrast to the effects on the first step, where TPO was inhibited by HgCl2 but never by CH3HgCl.
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Nukatsuka M, Yoshimura Y, Nishida M, Kawada J. Importance of the concentration of ATP in rat pancreatic beta cells in the mechanism of streptozotocin-induced cytotoxicity. J Endocrinol 1990; 127:161-5. [PMID: 2151740 DOI: 10.1677/joe.0.1270161] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The effects of streptozotocin (STZ) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) on monolayer cultures of rat pancreatic beta cells were compared. The intracellular NAD concentration was markedly decreased by both 2 mmol STZ/l and 13.6 mumol MNNG/l, but insulin secretion was decreased significantly only by STZ. The intracellular ATP level decreased rapidly and in a time-dependent manner with STZ, but decreased less on treatment with MNNG: 80% decrease with STZ but only 35% decrease with MNNG in 12 h in the cells exposed to the chemicals for 1 h and then washed thoroughly. STZ decreased oxygen consumption of rat liver mitochondria in a time- and dose-dependent manner and enhanced the generation of hydroxyl radicals (DMPO-adducts). This enhancement was doubled on the addition of succinate as a substrate. Mitochondrial ATP production was also decreased significantly by STZ, but not by MNNG. Thus the marked depletion of intracellular ATP in beta cells by STZ seems to be due mainly to a direct effect on mitochondrial production. From these results, we suggest that the cytotoxic effect of STZ in pancreatic beta cells is due to a reduction in the intracellular level of ATP, rather than of NAD.
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Teraoka K, Minakuchi K, Takasugi M, Akamatsu S, Nishida M, Kawada J. Variations in intrathyroidal lithium content and their effect on the iodide uptake in mouse thyroid. JOURNAL OF TRACE ELEMENTS AND ELECTROLYTES IN HEALTH AND DISEASE 1990; 4:169-73. [PMID: 2136134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Lithium (Li) is accumulated in the thyroid but the mechanism of Li accumulation is not known. In the present study, the causes of variation in Li concentration in the thyroid and the relation between cellular Li and iodide were examined. This was done by using mice treated with Li (0.01% as Li2CO3) for 4 weeks, co-administered with propylthiouracil (PTU, 0.5 mg/ml daily p.o.) or thyroxine (T4, 0.5 micrograms per day i.p.) for last 10 days. The total content of Li in a whole thyroid (ng/thyroid) was not changed through treatment with PTU or T4. But the Li concentration in terms of mg/kg of the gland was reduced with PTU and was unchanged or slightly increased with T4, due to the change in the mass of thyroid. Furthermore, short-term (3 h) Li uptake in the thyroid was not affected by pre-treatment with PTU or T4. These results indicate that the variation in thyroidal Li concentration was not due to a direct effect of PTU or T4 on Li transport, but to a thyroidal condition caused by the secondary influence of drugs. A measurement of the thyroid: serum iodide concentration ratio (T/S) of 125I showed that the iodide uptake was reduced when intracellular Li concentration was high, and that PTU alone elevated the T/S, but Li + PTU brought it back to a normal level; whereas, T4 alone diminished the T/S, Li + T4 made it rise significantly more than did T4 alone.(ABSTRACT TRUNCATED AT 250 WORDS)
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Nishida M, Yamashita K, Nukatsuka M, Otsuka M, Yoshimura Y, Kawada J. Direct evidence for ATP consumption due to iodide uptake by isolated, uncultured, pig thyroid epithelial cells. BIOCHEMISTRY INTERNATIONAL 1990; 21:1143-51. [PMID: 2150482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The concept that iodide uptake by thyroid requires a supply of ATP is currently accepted. However, there is little direct evidence that the extents of iodide uptake and ATP consumption are correlated. To demonstrate this correlation, we used isolated, uncultured pig thyroid epithelial cells in basal media containing only glucose and the cations necessary for Na+,K(+)-ATPase, which prevented other possible cellular activities requiring ATP. The isolated cells were sensitive to various metabolic inhibitors of ATP-generating systems, confirming that they were intact. The extents of increase in iodide uptake and decrease in ATP content of the cells were entirely dependent on the presence of the cations, and were closely correlated with each other. Furthermore, the ATP content was not reduced in the absence of NaI, even when all necessary cations for the ATPase were present. These findings provide direct evidence for a correlation between the extents of iodide uptake and ATP consumption. Cells in medium with Mg alone did not show iodide incorporation or ATP consumption, confirming that Mg2(+)-dependent ATPase does not contribute to iodide uptake by the thyroid.
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Kumamoto T, Toyooka K, Nishida M, Kuwahara H, Yoshimura Y, Kawada J, Kubota S. Effect of 2,4-dihydro-3H-1,2,4-triazole-3-thiones and thiosemicarbazones on iodide uptake by the mouse thyroid: the relationship between their structure and anti-thyroid activity. Chem Pharm Bull (Tokyo) 1990; 38:2595-6. [PMID: 1704818 DOI: 10.1248/cpb.38.2595] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Antithyroid activity of 2,4-dihydro-3H-1,2,4-triazole-3-thiones and thiosemicarbazones was tested by measuring the uptake ratio of thyroid: serum (T/S) of 125I through the mouse thyroid. Substitution with an alkyl group at the 5-position of the triazole nucleus remarkably increased the activity but substitution at the N-2 and/or N-4 positions caused a significant decrease in the activity, indicating the necessity of unsubstituted thioureylene moiety for the antithyroid activity. Thiosemicarbazone derivatives which are an open ring structure of triazoles showed comparable antithyroid activities to those in a ring form, but one thiosemicarbazone showed a much higher toxicity than the corresponding ring form compound. This suggests that the ring structure is not essential for the activity but is necessary to reduce toxic effect. Of fourteen compounds tested, 5-methyl-2,4-dihydro-3H-1,2,4-triazole-3-thione was the most potent antithyroid compound with low toxicity, with a potency tenfold that of propylthiouracil, a drug currently used.
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Sakurai H, Tsuchiya K, Nukatsuka M, Sofue M, Kawada J. Insulin-like effect of vanadyl ion on streptozotocin-induced diabetic rats. J Endocrinol 1990; 126:451-9. [PMID: 2170556 DOI: 10.1677/joe.0.1260451] [Citation(s) in RCA: 133] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Recent studies have indicated that the blood glucose level of rats with streptozotocin (STZ)-induced diabetes (type 1) is normalized without an increase in the plasma insulin level by administration of sodium orthovanadate in the drinking water. The mechanism of this insulin-like effect of vanadate is unknown. In this study, we investigated whether vanadyl ion, which is less toxic than vanadate to rats, also has an insulin-like effect in rats with STZ-induced diabetes. When rats with STZ-induced diabetes were given a daily i.p. injection of vanadyl sulphate (9.3 and 4.6 mg vanadium/kg body weight), their blood glucose level decreased from about 22.2 to about 7.2 mmol glucose/l within 2 days and remained low for at least 12 weeks. This treatment did not affect their low plasma insulin level. Quantitative electron spin resonance (ESR) spectrometry showed that most of the vanadium (about 90%) in their tissues was present as a vanadyl form (VO2+). ESR analysis also showed that the vanadyl ion in tissues was bound endogenously with four oxygen ligands from either water or oxyamino acid residues in proteins. Vanadyl sulphate accelerated glucose incorporation into adipocytes of rats, suggesting that the action of vanadyl ion is peripheral. Interestingly, vanadyl sulphate at a high concentration (about 10 mmol/l) was more effective than insulin in enhancing glucose uptake. This study demonstrated that: (1) vanadyl sulphate (+4 oxidation state), like vanadate ion, normalizes the blood glucose levels of rats with STZ-induced diabetes; (2) the action of vanadyl ion is peripheral; and (3) the active form of vanadium for an insulin-like effect may be a vanadyl form, not vanadate.
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Hirose G, Chujo T, Kataoka S, Kawada J, Yoshioka A. Acute effects of anticonvulsants on brain-stem auditory evoked potentials in rats. ELECTROENCEPHALOGRAPHY AND CLINICAL NEUROPHYSIOLOGY 1990; 75:543-7. [PMID: 1693898 DOI: 10.1016/0013-4694(90)90140-f] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Acute effects of various anticonvulsants on brain-stem auditory evoked potentials (BAEPs) in rats were tested. A high dose of phenytoin abolished all BAEP waves. Carbamazepine increased all 4 wave latencies. Phenobarbital and clonazepam increased the latencies of waves IV and III. Therefore, if BAEPs are to be used as an ancillary test for brain death, the possibility of significant effects of high dosages of anticonvulsants on BAEPs must be considered.
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Nishida M, Matsumoto H, Asano A, Umazume K, Yoshimura Y, Kawada J. Direct evidence for the presence of methylmercury bound in the thyroid and other organs obtained from mice given methylmercury; differentiation of free and bound methylmercuries in biological materials determined by volatility of methylmercury. Chem Pharm Bull (Tokyo) 1990; 38:1412-3. [PMID: 2393968 DOI: 10.1248/cpb.38.1412] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Peroxidase in mouse thyroid was inhibited by mercuric chloride but not by methylmercury in in vivo and in vitro systems (Nishida, et al., J. Histochem. Cytochem., 37, 723 (1989)). To identify the reason for the difference, the present study was conducted to examine whether methylmercury is indeed bound within cells or tissues. Mice were given radioactive methylmercury by intubation for 18 d and the tissues were dissected out and vacuum-dried. With this procedure, free methylmercury was evaporated off and the bound mercury remained. The thyroid, liver, kidney and fats examined showed no loss of radioactivity under the vacuum, indicating that the mercury was bound to the thyroid, as well as the other tissues. Radioactive mercuric chloride was nonvolatile regardless of the presence or absence of the tissues. The preferential affinity of methylmercury for SH-containing materials was re-confirmed by this method.
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Yoshioka A, Kitagawa Y, Kawada J, Negami T, Hirose G. [A case of unilateral VIIIth, IXth and Xth cranial nerve involvement with herpes zoster]. Rinsho Shinkeigaku 1990; 30:413-5. [PMID: 2167188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A 46-year-old healthy man suffered from sore throat, fever and right otalgia. On the next day, he developed hoarseness and difficulty in swallowing. On the 6th day, he suffered from vertigo, nausea and vomiting associated with unsteady gait. He was admitted to the otorhinolaryngology department in our hospital and pointed out to have vesicles at his right ear. On the 13th day, he was referred to our service. On admission, no vesicles were noted at the right ear or pharynx. Neurological examination revealed mild nuchal rigidity and marked hoarseness, associated with poor elevation of soft palate and loss of pharyngeal reflex on the right side. He also had horizontal-clockwise rotatory nystagmus in primary gaze and ataxic gait. There was no hearing loss nor facial palsy. No other abnormal neurological findings were noted. The cerebrospinal fluid showed pleocytosis associated with increased protein. The viral antibody titre for herpes zoster was significantly elevated on 18th day in serum as well as in cerebrospinal fluid. Vertigo, nausea, vomiting, ataxia and difficulty in swallowing were all disappeared by the 25th day, whereas hoarseness was improved but still noted 6 months later. Among cranial nerves, trigeminal and facial nerves are the most commonly affected in patients with herpes zoster, but there have been a few reported cases of the 9th and 10th cranial nerve involvement in the literature. In these previously reported cases, all were written before the era of serological diagnosis, and herpes zoster was diagnosed by the vesicles at the ear or pharynx.(ABSTRACT TRUNCATED AT 250 WORDS)
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