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Ikemoto S, Murphy JM, McBride WJ. Regional differences within the rat ventral tegmental area for muscimol self-infusions. Pharmacol Biochem Behav 1998; 61:87-92. [PMID: 9715810 DOI: 10.1016/s0091-3057(98)00086-0] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The present study examined the effects of activating GABA(A) receptors in the anterior and posterior regions of the ventral tegmental area (VTA) on operant reinforcement behavior, using the technique of intracranial self-administration. Rats were given the opportunity to self-administer vehicle alone (artificial CSF) and vehicle containing 25, 50, and 100 microM muscimol, a GABA(A) agonist, into the anterior or posterior VTA during four sessions (3 h/session) in standard two-lever operant chambers. Rats received five times greater infusions of 50 and 100 microM muscimol than vehicle into the posterior VTA; both doses significantly increased responding above vehicle levels on the active and inactive (control) levers equally. When the response requirement for muscimol infusions was increased from a fixed-ratio 1 (FR1) to FR3 in a single-lever chamber, the total session responses increased approximately twofold. Muscimol was not self-infused when cannula placements were in the anterior VTA. The self-infusion of muscimol into the posterior VTA was attenuated by coadministration of picrotoxin. Overall, the results suggest that the activation of GABA(A) receptors in the posterior VTA produces goal-directed behavior.
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Tsuboyama-Kasaoka N, Tsunoda N, Maruyama K, Takahashi M, Kim H, Ikemoto S, Ezaki O. Up-regulation of uncoupling protein 3 (UCP3) mRNA by exercise training and down-regulation of UCP3 by denervation in skeletal muscles. Biochem Biophys Res Commun 1998; 247:498-503. [PMID: 9642158 DOI: 10.1006/bbrc.1998.8818] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In skeletal muscles, increased utilization of lipids and carbohydrates accompanied with increased energy expenditure has been observed during and after exercise. UCP3, mitochondrial uncoupling protein, is expressed in skeletal muscles. We investigated UCP3 mRNA levels in exercise training mice which increased energy expenditure and in sciatic nerve-denervated mice which decreased energy expenditure. Mice exercised by 2 wk swimming had 14- to 18-fold increases of UCP3 mRNA in skeletal muscles 3 h after the last swimming, but no increases of UCP1 mRNA in BAT and of UCP2 mRNA in WAT. However, 22 h after exercise, UCP3 mRNA increases observed in skeletal muscles 3 h after exercise returned to sedentary levels. Similar transient increases of UCP3 mRNA were observed in 1 wk treadmill running training or a single exercise bout. In denerved gastrocnemius, GLUT4 and UCP3 mRNA decreased by 58 and 45%, respectively. These data indicate that UCP3 may have a role for fine adjustments of energy expenditure and that up-regulation of UCP3 mRNA may be a defense mechanism against extra energy supply to consume extra energy in skeletal muscles.
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78
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Tsunoda N, Ikemoto S, Takahashi M, Maruyama K, Watanabe H, Goto N, Ezaki O. High-monounsaturated fat diet-induced obesity and diabetes in C57BL/6J mice. Metabolism 1998; 47:724-30. [PMID: 9627373 DOI: 10.1016/s0026-0495(98)90037-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A high-monounsaturated fat diet has been proposed as a palatable alternative to a high-carbohydrate diet in diabetic patients, but it is unknown whether a higher intake of monounsaturated fat induces obesity and diabetes, as usually observed with other types of fat. To answer this question, C57BL/6J mice were divided into three groups: the first group was given a high-carbohydrate diet, and the other two groups were given a high-monounsaturated fat diet (60% of total energy) as olive oil or synthetic triolein for 4 months. It has been previously reported that the C57BL/6J mouse has a genetic predisposition for intraabdominal obesity and non-insulin-dependent diabetes mellitus (NIDDM) by high-polyunsaturated fat (n-6) feeding. Although there were no significant differences in energy intake and fat absorption among these three groups, compared with the high-carbohydrate diet, both high-monounsaturated fat diets produced hyperglycemia, obesity, and triglyceride accumulation in the liver and skeletal muscle. These data indicate that the recently recommended high-monounsaturated fat diet might induce obesity and diabetes.
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79
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Yui K, Ishiguro T, Goto K, Ikemoto S. Factors affecting the development of spontaneous recurrence of methamphetamine psychosis. Acta Psychiatr Scand 1998; 97:220-7. [PMID: 9543311 DOI: 10.1111/j.1600-0447.1998.tb09991.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The process triggering spontaneous recurrences of methamphetamine (MAP) psychosis (i.e. flashbacks) was studied in 41 flashbackers, along with 84 non-flashbackers with a history of MAP psychosis. Plasma monoamine metabolite levels were assayed in 25 of the 41 flashbackers, 16 of the 84 non-flashbackers, 9 subjects with persistent MAP psychosis and 28 control subjects. All flashbackers had experienced threatening events or frightening paranoid-hallucinatory states during previous MAP use. The dominant factor triggering flashbacks was a mild fear of other people. Plasma norepinephrine levels were elevated during flashbacks. The results suggest that a mild fear of other people may have elicited memories of MAP psychosis associated with threatening experiences through increased sensitivity to psychosocial stressors. As a result the flashbacks occurred, including an increase in peripheral noradrenergic activity.
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80
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Lee CC, Masuda C, Yamamoto S, Wanibuchi H, Ikemoto S, Sugimura K, Nakatani T, Wada S, Kishimoto T, Fukushima S. Assessment of cell cycle-related elements p53, p21WAF1/Cip1, cyclin D1 and PCNA in a mixed transitional cell carcinoma and adenocarcinoma of the renal pelvis: a case report. Jpn J Clin Oncol 1998; 28:227-32. [PMID: 9614448 DOI: 10.1093/jjco/28.3.227] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A case featuring a well differentiated adenocarcinoma mixed with a transitional cell carcinoma (TCC) arising in the renal pelvis of a 63-year-old woman is presented. Daughter tumors, located in the ureter and the uretero-vesical junction, were entirely TCC in character. Immunohistochemical assessment of cell cycle-related proteins revealed overexpression of cyclin D1 but reduced p21WAF1/Cip1 or PCNA expression in the adenocarcinomatous regions. Conversely, expression of p21WAF1/Cip1 and PCNA was high in the TCC components. Immunohistochemical staining for p53 was negative and PCR-SSCP analyses confirmed the absence of any mutation. Therefore, assessments on the altered expression of cell cycle-related elements may contribute to our understanding of tumor biology in adenocarcinomas and TCCs of the renal pelvis and to identifying the similarities and differences between the two different cell types.
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81
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Ikemoto S, Glazier BS, Murphy JM, McBride WJ. Rats self-administer carbachol directly into the nucleus accumbens. Physiol Behav 1998; 63:811-4. [PMID: 9618003 DOI: 10.1016/s0031-9384(98)00007-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The potential reinforcing effect of the muscarinic cholinergic agonist carbachol within the nucleus accumbens (ACB) was examined in female Wistar rats by using the technique of intracranial self-administration. Rats dose dependently self-administered solutions of 0.0-6.6 mM (in a volume of 100 nL per injection) directly into the ACB. Rats self-administered the 3.3 and 6.6 mM doses significantly more than the group given only vehicle. The caudate putamen did not support reliable self-administration of the 6.6-mM dose. Rats exhibited preference for the lever that produced infusions of 3.3 and 6.6 mM carbachol into the ACB over the lever that had no consequence. The self-infusion of the 6.6-mM dose into the ACB was inhibited by the coadministration of the muscarinic antagonist scopolamine (0.25 mM), but not by the nicotinic antagonist mecamylamine (6.6 mM). The present results suggest that direct activation of muscarinic receptors within the ACB supports self-administration and could result from reinforcement or from elicitation of a novel stimulus.
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82
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Yui K, Ishiguro T, Goto K, Ikemoto S. Precipitating factors in spontaneous recurrence of methamphetamine psychosis. Psychopharmacology (Berl) 1997; 134:303-8. [PMID: 9438680 DOI: 10.1007/s002130050453] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
This paper examines noradrenergic hyperactivity in response to stress in the development of spontaneous recurrences of methamphetamine (MAP) psychosis, a phenomenon known as flashbacks, in studies of psychedelic drug use. We studied predictors of flashbacks in 36 subjects with flashbacks, along with 80 subjects with a history of MAP psychosis who did not experience flashbacks. Plasma monoamine metabolite levels were assayed in 26 of the 36 subjects with flashbacks, 16 of the 80 subjects without flashbacks, nine subjects with persistent MAP psychosis, and 28 normal controls. None of the 28 controls became psychotic. A square root transformation was applied to all monoaminergic values, resulting in data nearly normally distributed. The subjects with flashbacks had been exposed to stressful events or threatening paranoid-hallucinatory states or both during previous MAP use. Most flashbacks occurred under conditions that provoked a mild fear of other people. Plasma norepinephrine levels were markedly increased during flashbacks. Thus, stressful experiences together with MAP use may have induced noradrenergic hyperreactivity to a mild stress, which in turn may elicit memories of MAP psychosis associated with stressful experiences. A mild fear of other people precipitated the flashbacks, including markedly increased noradrenergic activity. The results of this study suggest that noradrenergic hyperreactivity to a mild stress is a precipitating factor in spontaneous recurrences of MAP psychosis.
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83
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Zaman MM, Ikemoto S, Yoshiike N, Date C, Yokoyama T, Tanaka H. Association of apolipoprotein genetic polymorphisms with plasma cholesterol in a Japanese rural population. The Shibata Study. Arterioscler Thromb Vasc Biol 1997; 17:3495-504. [PMID: 9437198 DOI: 10.1161/01.atv.17.12.3495] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The association between apolipoprotein (apo) genetic polymorphisms and lipid phenotypes remains to be determined because such studies have reported contradictory results. We have measured plasma total cholesterol (TC) and HDL cholesterol (HDL-C) in a cross-sectional sample of 1328 (462 men and 866 women) Japanese (aged 40 to 80 years) and analyzed their DNA for the following genotypes: apoA1-C3 Msp I and Sst I sites; apoB signal peptide insertion/deletion, Xba I site and 3' variable number of tandem repeats (VNTR); and apoE. Using multivariate analyses (ANOVA) we found that (1) the polymorphisms of apoA1-C3 and apoB genes are not significantly associated with TC or HDL-C and (2) the polymorphism of the apoE gene is significantly related with TC and the TC:HDL-C ratio. The epsilon 2 carriers have lower levels of TC and a lower TC:HDL-C ratio, epsilon 3 carriers have intermediate levels, and epsilon 4 carriers have higher levels. These findings held whether sexes were analyzed separately or together. Although an opposite trend in HDL-C levels was observed, it did not reach the level of statistical significance. Multiple regression analyses have shown that apoE polymorphism accounts for about 2.3% of the variation in TC and TC:HDL-C ratio irrespective of sex. When the subjects are divided into two groups according to their age (< or = 59 and > or = 60 years old), the effect of apoE alleles on serum cholesterols appears to be diluted in the younger age group whereas it appears to be accentuated in the older group for both sexes. Our findings suggest that among the apo genetic polymorphisms examined, the apoE gene may be considered as a possible candidate for the "high-risk" strategy of atherosclerosis prevention in the Japanese population.
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Abstract
A guanine-adenine substitution was observed in exon 5 of the human transferrin (TF) gene. The nucleotide change led to an AvaI digestion site. Analysis of the segregation of the AvaI polymorphism and serum TF phenotypes indicated that an intragenic recombination occurred between the AvaI polymorphic site and the mutation site in the TF gene which determines the two common TF alleles, TF*C1 and TF*C2.
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85
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Ikemoto S, Glazier BS, Murphy JM, McBride WJ. Role of dopamine D1 and D2 receptors in the nucleus accumbens in mediating reward. J Neurosci 1997; 17:8580-7. [PMID: 9334429 PMCID: PMC6573749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The objectives of this study were to examine the involvement of D1 and D2 receptors within the nucleus accumbens (ACB) in mediating reinforcement. The intracranial self-administration (ICSA) of D1 and D2 agonists was used to determine whether activating D1 and/or D2 receptors within the ACB of Wistar rats is reinforcing. At concentrations of 0.25, 0.50, and 1.0 mM (25, 50, and 100 pmol/100 nl of infusion), neither the D1 agonist R(+)-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine-7,8-diol [SKF 38393 (SKF)] hydrochloride nor the D2 agonist (-)-quinpirole (Quin) hydrochloride was self-administered into the shell region of the ACB. On the other hand, equimolar mixtures of SKF and Quin (SKF+Quin), at concentrations of 0.25, 0.50, and 1.0 mM each, were significantly self-infused into the ACB shell. The core region of the ACB did not support the ICSA of SKF+Quin at any of these concentrations. Rats increased lever pressing when the response requirement was increased from a fixed ratio 1 (FR1) to FR3, and they responded significantly more on the infusion lever than they did on the control lever. Coadministration of either 0.50 mM R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4, 5-tetrahydro-1H-3-benzazepine (SCH 23390) hydrochloride, a D1 antagonist, or 0.50 mM S(-)-sulpiride, a D2 antagonist, completely abolished the ICSA of the mixture of SKF+Quin (each at 0.50 mM) into the ACB shell. The present results suggest that concurrent activation of D1- and D2-type receptors in the shell of the ACB had a cooperative effect on DA-mediated reward processes.
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MESH Headings
- 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine/administration & dosage
- 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine/pharmacology
- Animals
- Appetitive Behavior/drug effects
- Appetitive Behavior/physiology
- Benzazepines/pharmacology
- Dopamine Agonists/administration & dosage
- Dopamine Agonists/pharmacology
- Dopamine Antagonists/pharmacology
- Dose-Response Relationship, Drug
- Drug Interactions
- Female
- Goals
- Injections
- Nucleus Accumbens/cytology
- Nucleus Accumbens/physiology
- Quinpirole/administration & dosage
- Quinpirole/pharmacology
- Rats
- Rats, Wistar
- Receptors, Dopamine D1/drug effects
- Receptors, Dopamine D1/physiology
- Receptors, Dopamine D2/drug effects
- Receptors, Dopamine D2/physiology
- Reward
- Self Administration
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86
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Tsunoda N, Cooke DW, Ikemoto S, Maruyama K, Takahashi M, Lane MD, Ezaki O. Regulated expression of 5'-deleted mouse GLUT4 minigenes in transgenic mice: effects of exercise training and high-fat diet. Biochem Biophys Res Commun 1997; 239:503-9. [PMID: 9344860 DOI: 10.1006/bbrc.1997.7516] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Fourteen kb murine GLUT4 minigene (= -7395 GLUT4) contains DNA sequence that confers tissue specific, exercise-induced up-regulation of the GLUT4 gene in skeletal muscle and high-fat diet induced-down-regulation in white adipose tissue. To identify the DNA sequences required for regulated expression, we generated GLUT4 minigene transgenic mice harboring 3237, 2000, 1000, and 442 bp of 5'-flanking region, all exons and introns, and 1 kb of 3'-flanking sequence of the mouse GLUT4 gene. The -3237-, -2000-, and -1000-GLUT4 constructs were expressed in a tissue-specific manner identical to the endogenous GLUT4. Exercise-induced up-regulation and high-fat diet-induced down-regulation of these constructs also paralleled those of the endogenous GLUT4 gene. In contrast, the -442 GLUT4 construct was expressed substantially in skeletal muscle (gastrocnemius and quadriceps) and heart, but was only expressed very weakly in white adipose tissue and was not expressed in brown adipose tissue. Furthermore, this -442 GLUT4 construct failed to respond to exercise or a high-fat diet in either muscle or adipose tissue. These results indicate that brown and white adipocyte-specific enhancer(s) and exercise- and high-fat diet-responsive elements are located between bases -1000 and -442 of the murine GLUT4 5'-flanking region.
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87
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Ikemoto S, McBride WJ, Murphy JM, Lumeng L, Li TK. 6-OHDA-lesions of the nucleus accumbens disrupt the acquisition but not the maintenance of ethanol consumption in the alcohol-preferring P line of rats. Alcohol Clin Exp Res 1997; 21:1042-6. [PMID: 9309315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The aim of the present study was to determine whether reduction of dopamine (DA) innervation to the nucleus accumbens (ACB) alters the maintenance and/or acquisition of ethanol drinking in female alcohol-preferring P rats. Compared with sham-lesioned animals, bilateral microinjections of 6-OHDA (12 micrograms/2.4 microliters/site) into the ACB did not alter the consumption of 10% ethanol in rats that had prior experience of ethanol drinking, with both sham- and 6-OHDA-lesioned groups recovering to presurgical consumption levels at similar rates. On the other hand, the identical lesion procedure disrupted the acquisition of ethanol intake in rats with no ethanol-drinking experience prior to the lesions. A sham-lesioned group attained an ethanol intake of approximately 7 g/kg/day in 1 week, which was maintained over the following 2-week period, while the ethanol intake of the 6-OHDA-lesioned group was approximately 60% lower after 1 week and 30% lower at the end of 3 weeks. DA content of the ACB was 60% lower in both groups of the 6-OHDA-treated rats compared with the controls. The results suggest that different neural mechanisms may underlie the acquisition and maintenance of ethanol drinking behavior; the ACB DA system appears to play an important role in the acquisition of ethanol drinking.
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88
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Kawakami S, Kaibara M, Nakayama M, Isogai Y, Ikemoto S, O'Rear EA, Lee JS. Rheological study of the dynamic process of fibrinolysis. Blood Coagul Fibrinolysis 1997; 8:351-9. [PMID: 9351525 DOI: 10.1097/00001721-199709000-00005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The dynamic process of fibrinolysis induced by tissue plasminogen activator was examined using a rheological technique. Change in a rheological parameter (logarithmic damping factor) of whole blood and platelet-free plasma during fibrinolysis was largely dependent on the initial concentration of tissue plasminogen activator. Addition of activated partial prothrombin time reagent allowed determination of the time both of onset and end of fibrinolysis without affecting the coagulation process. The changes in the clot structure of fibrin during fibrinolysis were observed with a scanning electron microscope and compared with the time-dependent behavior of the logarithmic damping factor. Differences in the logarithmic damping factor during fibrinolysis were evident in alteration of the network structure of clots. It will be shown that the present rheological technique is useful for examining the concentration dependence of fibrinolytic reagent on fibrinolysis as well as for monitoring the dynamic process of fibrinolysis.
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89
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Ikemoto S, Kohl RR, McBride WJ. GABA(A) receptor blockade in the anterior ventral tegmental area increases extracellular levels of dopamine in the nucleus accumbens of rats. J Neurochem 1997; 69:137-43. [PMID: 9202304 DOI: 10.1046/j.1471-4159.1997.69010137.x] [Citation(s) in RCA: 125] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Previously, it was shown that microinfusion of the GABA(A) antagonist picrotoxin into the anterior ventral tegmental area (VTA) is reinforcing. It was hypothesized that this reinforcing effect of picrotoxin in the anterior VTA is mediated, at least in part, by the activation of the mesoaccumbens dopamine (DA) system. The objective of the present study was to determine if blockade of GABA(A) receptors in the anterior VTA can increase extracellular levels of DA in the nucleus accumbens (ACB), using an in vivo microdialysis technique in freely moving rats. Concentrations of picrotoxin (40, 80, and 160 microM) that had previously been shown to produce a reinforcing effect increased the extracellular levels of DA and its major metabolites in the ACB. The increased extracellular DA levels induced by intra-VTA injection of picrotoxin was markedly attenuated by coadministration with the GABA(A) agonist muscimol, whereas intra-VTA injection of muscimol alone did not have an apparent effect on extracellular DA levels in the ACB. Microinjection of another GABA(A) antagonist, bicuculline, into the anterior VTA also increased the extracellular release of DA in the ACB. These results suggest that DA neurons projecting from the anterior VTA to the ACB are tonically inhibited by GABA through its actions at the GABA(A) receptors.
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90
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Ikemoto S, Takahashi M, Tsunoda N, Maruyama K, Itakura H, Kawanaka K, Tabata I, Higuchi M, Tange T, Yamamoto TT, Ezaki O. Cholate inhibits high-fat diet-induced hyperglycemia and obesity with acyl-CoA synthetase mRNA decrease. THE AMERICAN JOURNAL OF PHYSIOLOGY 1997; 273:E37-45. [PMID: 9252477 DOI: 10.1152/ajpendo.1997.273.1.e37] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The effects of sodium cholate on high-fat diet-induced hyperglycemia and obesity were investigated. Insulin resistance was estimated by measuring 2-deoxyglucose uptake in epitrochlearis muscles incubated in vitro. Addition of 0.5% cholate to high-safflower oil diet completely prevented high fat-induced hyperglycemia and obesity in C57BL/6J mice with a slight decrease of energy intake but with no inhibition of fat absorption. Furthermore, the addition of cholate decreased blood insulin levels and prevented high-fat diet-induced decrease of glucose uptake in epitrochlearis. However, there was no change in the unsaturation index of fatty acids in skeletal muscles and in GLUT-4 levels by cholate. In liver, cholate addition resulted in cholesterol accumulation and completely prevented high-fat diet-induced triglyceride accumulation. The changes of triglyceride level in the liver were paralleled to the changes of acyl-CoA synthetase (ACS) mRNA. ACS catalyzes the formation of acyl-CoA from fatty acid, and acyl-CoA is utilized for triglyceride formation in liver. ACS has a sterol-responsive element 1 in its promoter region. These data indicate that the favorable effects of cholate could be partly the result of downregulation of ACS mRNA.
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91
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Ikemoto S, Murphy JM, McBride WJ. Self-infusion of GABA(A) antagonists directly into the ventral tegmental area and adjacent regions. Behav Neurosci 1997. [PMID: 9106676 DOI: 10.1037//0735-7044.111.2.369] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This study used an intracerebral self-administration paradigm in rats to determine if blockade of GABA(A) receptors in the ventral tegmental area (VTA) has a reinforcing effect. Rats quickly learned to self-infuse a picrotoxin solution into the anterior VTA; rats discriminated the lever that produced picrotoxin infusions from the lever without consequences; and when the response requirement was increased, rats increased response levels for picrotoxin infusion. The reinforcing effect of picrotoxin was site-specific: Anterior VTA regions supported vigorous self-infusions, but not the posterior VTA, substantia nigra, or lateral hypothalamus. Muscimol, a GABA(A) agonist, disrupted picrotoxin self-infusion, but bicuculline, a GABA(A) antagonist, was self-infused into the VTA. The results suggest that blockade of GABA(A) receptors in the anterior VTA is reinforcing and that functional organization of the GABA systems within the VTA is heterogeneous.
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92
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Ikemoto S, Murphy JM, McBride WJ. Self-infusion of GABA(A) antagonists directly into the ventral tegmental area and adjacent regions. Behav Neurosci 1997; 111:369-80. [PMID: 9106676 DOI: 10.1037/0735-7044.111.2.369] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
This study used an intracerebral self-administration paradigm in rats to determine if blockade of GABA(A) receptors in the ventral tegmental area (VTA) has a reinforcing effect. Rats quickly learned to self-infuse a picrotoxin solution into the anterior VTA; rats discriminated the lever that produced picrotoxin infusions from the lever without consequences; and when the response requirement was increased, rats increased response levels for picrotoxin infusion. The reinforcing effect of picrotoxin was site-specific: Anterior VTA regions supported vigorous self-infusions, but not the posterior VTA, substantia nigra, or lateral hypothalamus. Muscimol, a GABA(A) agonist, disrupted picrotoxin self-infusion, but bicuculline, a GABA(A) antagonist, was self-infused into the VTA. The results suggest that blockade of GABA(A) receptors in the anterior VTA is reinforcing and that functional organization of the GABA systems within the VTA is heterogeneous.
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93
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Yui K, Goto K, Ishiguro T, Ikemoto S. Noradrenergic activity and spontaneous recurrence of methamphetamine psychosis. Drug Alcohol Depend 1997; 44:183-7. [PMID: 9088791 DOI: 10.1016/s0376-8716(97)01336-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The process that triggers flashbacks due to previous methamphetamine (MAP) psychosis was studied in 28 flashbackers, along with 84 non-flashbackers with a history of MAP psychosis. We measured plasma monoamine metabolite levels in 12 of the flashbackers and eight of the non-flashbackers, along with 28 normal controls. Most flashbackers had undergone frightening experiences during previous MAP use. The dominant triggering factor was a mild fear of other people. Plasma norepinephrine (NE) levels in the 12 flashbackers were increased during flashbacks. Thus, MAP use associated with threatening experiences may have increased sensitivity to stressors, leading to the occurrence of flashbacks, including exaggerated noradrenergic activity.
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94
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Lee CC, Yamamoto S, Morimura K, Wanibuchi H, Nishisaka N, Ikemoto S, Nakatani T, Wada S, Kishimoto T, Fukushima S. Significance of cyclin D1 overexpression in transitional cell carcinomas of the urinary bladder and its correlation with histopathologic features. Cancer 1997; 79:780-9. [PMID: 9024716 DOI: 10.1002/(sici)1097-0142(19970215)79:4<780::aid-cncr15>3.0.co;2-w] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Genetic alterations leading to neoplastic transformation of the urothelium are likely to involve the activation of oncogenes and loss of functional tumor suppressor genes. Cyclin D1 has been implicated as a putative protooncogene whereas mutations of the p53 gene occur frequently in invasive transitional cell carcinomas (TCCs) of the urinary bladder. In this study, cyclin D1 overexpression and nuclear accumulation of p53 were evaluated and the results correlated with histopathologic features. METHODS TCCs of the urinary bladder from 161 surgical procedures were evaluated for cyclin D1 overexpression and nuclear accumulation of p53. Results were correlated with tumor grade, T classification, and papillary status. Topologic distributions of cyclin D1, p53, and proliferating cellular nuclear antigen (PCNA) were evaluated. Northern blot analysis was performed on selected specimens. RESULTS Overexpression of cyclin D1 was observed in 47% (24 of 51) of Grade 1 TCCs and 20% (13 of 65) of Grade 2 TCCs but in no Grade 3 TCCs. Approximately 34% (14 of 41) of Ta classified TCCs and 21% (13 of 63) of T1 classified TCCs were immunoreactive for cyclin D1 whereas none of the TCCs beyond T1 was immunoreactive. Overexpression of cyclin D1 was observed only in papillary type TCCs. Results of Northern blot analysis for cyclin D1 were comparable to those of immunohistochemistry. CONCLUSIONS The observed significant relation between cyclin D1 overexpression and tumor grade/T classification suggests that cyclin D1 may be a useful biologic marker for biopsied materials or urine cytology specimens. The prognostic significance of cyclin D1 overexpression in TCCs remains to be determined.
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95
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Yui K, Goto K, Ikemoto S, Ishiguro T. Methamphetamine psychosis: spontaneous recurrence of paranoid-hallucinatory states and monoamine neurotransmitter function. J Clin Psychopharmacol 1997; 17:34-43. [PMID: 9004055 DOI: 10.1097/00004714-199702000-00007] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We studied the process that triggers spontaneous recurrences of methamphetamine (MAP) psychosis, a phenomenon known as flashbacks, in 28 female patients who experienced flashbacks, by comparing them with 92 female nonflashbackers with a history of previous MAP psychosis. The study evaluated plasma monoamine neurotransmitter function in 12 of the 28 flashbackers and in 8 of the 92 nonflashbackers. Control data were obtained from 28 normal, healthy females composed of 13 MAP users and 15 nonusers, none of whom became psychotic. The 28 flashbackers had experienced significantly greater frequencies of threatening events and frightening paranoid-hallucinatory states during previous MAP abuse than the 92 nonflashbackers. The dominant triggering factor was a mild fear of other persons. Plasma norepinephrine (NE) levels were significantly higher in the 12 flashbackers during flashbacks than during periods of normalcy and were significantly higher than those in the 13 user and 15 nonuser control subjects. Plasma NE levels in the 12 flashbackers during periods of normalcy were significantly higher than those in the 13 user control subjects. The eight nonflashbackers had significantly higher NE levels than the 13 user control subjects. This suggests that an increase in peripheral noradrenergic activity may be related to the occurrence of flashbacks. The present study suggests that repeated MAP use with frightening experiences may induce sensitivity to psychosocial stressors. A mild fear of other persons may have actualized the encoded frightening memories associated with the frightening experiences via increased sensitivity to psychosocial stressors. Thus, flashbacks may have been caused through an increase in peripheral noradrenergic activity.
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96
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Yui K, Goto K, Ikemoto S, Ishiguro T. Monoamine neurotransmitter metabolites and spontaneous recurrence of methamphetamine psychosis. Brain Res Bull 1997; 43:25-33. [PMID: 9205790 DOI: 10.1016/s0361-9230(96)00340-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The present study was conducted to evaluate plasma levels of monoamine neurotransmitter metabolites in spontaneous recurrences of methamphetamine psychosis (i.e., flashbacks). The subjects were 50 physically healthy females comprised of 25 who experienced flashbacks (flashbackers), 18 who did not experienced methamphetamine psychosis, and 9 who were currently suffering from persistent methamphetamine psychosis. The control data were available from 28 normal healthy females, of whom 20 had previously abused methamphetamine (users) and 8 who had not (nonusers), none of whom had ever become psychotic. Plasma levels of norepinephrine (NE), dopamine (DA), and 5-hydroxytryptamine (5-HT), and their respective metabolites were assayed. Plasma NE levels were significantly higher in the 25 flashbackers during their flashbacks than during their periods of normalcy, and were significantly higher than those in the 20 user and 8 nonuser controls. Plasma 3-methoxy-4-hydroxyphenylglycol (MHPG) levels during flashbacks were significantly higher than those in the 20 user controls. The nine subjects with persistent methamphetamine psychosis had significantly higher NE levels than the user and nonuser controls. The 16 nonflashbackers had significantly higher MHPG levels than the user controls. The present study suggests that an increase in peripheral noradrenergic activity is related to the occurrence of flashbacks.
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97
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Ikemoto S, Kamizuru M, Wada S, Asai Y, Kishimoto T. Changes in lymphocyte subsets following administration of interleukin 2 and cyclophosphamide in mice with transitional cell carcinoma. Oncol Res 1997; 9:71-5. [PMID: 9167188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We investigated the effects of combination therapy with interleukin 2(IL-2) and cyclophosphamide (CPM) in C3H/HeN mice implanted with mouse bladder tumor cells (MBT2). Tumor growth was suppressed in the mice treated with IL-2 alone and mice treated with CPM alone, although not completely. However, tumor growth was completely suppressed in the mice treated with both IL-2 and CPM. As for lymphocyte subset analysis of the spleen using flow cytometry, the frequency of Lyt2+ cells and asialo GM1+ cells was significantly higher in the mice treated with IL-2 and CPM compared to the other groups. In the lymphocyte subset analysis of the thymus, the frequency of L3T4-Lyt2+ cells was significantly lower in the mice treated with CPM alone and mice treated with IL-2 and CPM compared to the other groups.
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98
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Ikemoto S, Takahashi M, Tsunoda N, Maruyama K, Itakura H, Ezaki O. High-fat diet-induced hyperglycemia and obesity in mice: differential effects of dietary oils. Metabolism 1996; 45:1539-46. [PMID: 8969289 DOI: 10.1016/s0026-0495(96)90185-7] [Citation(s) in RCA: 220] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Mice fed a high-fat diet develop hyperglycemia and obesity. Using non-insulin-dependent diabetes mellitus (NIDDM) model mice, we investigated the effects of seven different dietary oils on glucose metabolism: palm oil, which contains mainly 45% palmitic acid (16:0) and 40% oleic acid (18:1); lard oil, 24% palmitic and 44% oleic acid; rapeseed oil, 59% oleic and 20% linoleic acid (18:2); soybean oil, 24% oleic and 54% linoleic acid; safflower oil, 76% linoleic acid; perilla oil, 58% alpha-linolenic acid; and tuna fish oil, 7% eicosapentaenoic acid and 23% docosahexaenoic acid. C57BL/6J mice received each as a high-fat diet (60% of total calories) for 19 weeks (n = 6 to 11 per group). After 19 weeks of feeding, body weight induced by the diets was in the following order: soybean > palm > or = lard > or = rapeseed > or = safflower > or = perilla > fish oil. Glucose levels 30 minutes after a glucose load were highest for safflower oil (approximately 21.5 mmol/L), modest for rapeseed oil, soybean oil, and lard (approximately 17.6 mmol/L), mild for perilla, fish, and palm oil (approximately 13.8 mmol/L), and minimal for high-carbohydrate meals (approximately 10.4 mmol/L). Only palm oil-fed mice showed fasting hyperinsulinemia (P < .001). By stepwise multiple regression analysis, body weight (or white adipose tissue [WAT] weight) and intake of linoleic acid (or n-3/n-6 ratio) were chosen as independent variables to affect glucose tolerance. By univariate analysis, the linoleic acid intake had a positive correlation with blood glucose level (r = .83, P = .02) but not with obesity (r = .46, P = .30). These data indicate that (1) fasting blood insulin levels vary among fat subtypes, and a higher fasting blood insulin level in palm oil-fed mice may explain their better glycemic control irrespective of their marked obesity; (2) a favorable glucose response induced by fish oil feeding may be mediated by a decrease of body weight; and (3) obesity and a higher intake of linoleic acid are independent risk factors for dysregulation of glucose tolerance.
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Nishisaka N, Wada S, Ikemoto S, Sugimura K, Nakatani T, Horii A, Yamamoto K, Kishimoto T, Kawano M, Yasumoto R, Tsujino T. [The effectiveness of neoadjuvant chemotherapy for invasive bladder cancer]. Nihon Hinyokika Gakkai Zasshi 1996; 87:1250-7. [PMID: 8969547 DOI: 10.5980/jpnjurol1989.87.1250] [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: 02/03/2023]
Abstract
BACKGROUND Sixteen patients with invasive bladder cancer were received neoadjuvant methotrexate, vinblastine, pirarubicin and cisplatin chemotherapy on our planning protocol. METHODS The tumor was evaluated after 1 course of chemotherapy by radiographic examination, urine cytology, cystoscopy and random biopsy. If the response is CR or PR, one more course of chemotherapy was performed, and cystectomy was carried out. If the response is NC or PD, cystectomy was immediately carried out. Twelve of them were underwent cystectomy and four were preserved bladder. Clinical response was evaluated by echo, CT, MRI, urinary cytology, cystoscopy and random biopsy. RESULTS Clinical CR was observed in 25% and PR was 37.5%. Pathological CR was observed in 31.3% and PR was 37.5%. The different rate between clinical and pathological evaluations was 31.3% and the result suggests that we should find the method of more accurate staging evaluation. Four patients who were evaluated clinical CR were selected bladder-preserving. However, two of them (50%) had recurred; one had grade 3 tumor was treated by total cystectomy and the other had multiple tumors was treated by one course of M-VAC and TUR-Bt. CONCLUSION We should consider which cases are possible to preserve bladder by investigating the tumor characteristics.
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Yui K, Goto K, Ikemoto S, Ishiguro T. Monoamine neurotransmitter function and spontaneous recurrence of methamphetamine psychosis. Ann N Y Acad Sci 1996; 801:415-29. [PMID: 8959056 DOI: 10.1111/j.1749-6632.1996.tb17464.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The process that triggered spontaneous recurrence of methamphetamine (MAP)-induced paranoid-hallucinatory psychosis, a phenomenon known as flashbacks, was studied in 41 subjects with flashbacks, along with 84 subjects with a history of previous MAP psychosis but no flashbacks. Plasma levels of norepinephrine (NE), dopamine, and 5-hydroxytryptamine, and their respective metabolites were assayed in 28 of the 41 flashbackers, 16 of the 84 non-flashbackers, 9 subjects with persistent MAP psychosis, and 28 healthy controls comprised of 20 MAP users and 8 non-users. None of the 28 controls had become psychotic. The 41 flashbackers had experienced significantly greater frequencies of threatening events and frightening paranoid-hallucinatory states during previous MAP use than the 84 non-flashbackers. The dominant factor that triggered flashbacks was a mild fear of other persons. The 41 flashbackers may have encoded threatening experiences as frightening images. Repeated MAP use with threatening experiences may induce sensitization to frightening images. Plasma NE levels during flashbacks were significantly higher than the levels during periods of normalcy, and the NE levels in the 20 user and 8 non-user controls. The 9 subjects with persistent MAP psychosis had significant higher levels of NE than the user and non-user controls. The 16 non-flashbackers had significantly higher MHPG levels than the user controls. The findings suggest that MAP use may induce changes at pharmacological levels in the process underlying sensitization to frightening images. We suggested that when the flashbackers experienced a mild fear of other persons, MAP-induced sensitization to frightening images may have been actualized. Thus, the flashbacks may have been caused through increased noradrenergic hyperactivity.
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