A Novel Animal Model of Nonalcoholic Steatohepatitis (NASH): Hypoxemia Enhances the Development of NASH

Recent reports described a high incidence of nonalcoholic steatohepatitis (NASH) in patients with obstructive sleep apnea. Accordingly, we hypothesized that recurrent and intermittent hypoxemia plays an important role in the pathogenesis of NASH. Our objective was construction of a practical and accurate experimental model to reproduce the key features of NASH in humans. Chemical hypoxemia through methemoglobinemia was induced by daily intraperitoneal injection of sodium nitrite (40 mg/kg) for 4 weeks in rats with fatty liver. The later was induced by 4-week feeding a choline-deficient high-fat diet (CDHF). Besides, the normal chow diets feeding groups were prepared with in the same manner except for CDHF feeding. The animal experiment was performed in four groups; Normal control, Hypoxemia, CDHF, and CDHF + hypoxemia. Nitrite was given for the later 4 weeks to each rat of Hypoxemia and CDHF + hypoxemia. CDHF + hypoxemia rats were confirmed to develop histological changes that resemble those of patients with NASH, together with biochemical liver dysfunction, while CDHF group was limited in mild steatosis, and Hypoxemia group liver was normal. Present study established a reproducible and useful NASH model resembling the main features of NASH in humans, and showed first that recurrent and intermittent hypoxemia aggravate fatty liver to steatohepatitis and liver fibrosis

Beneficial Effects of Fermented Green Tea Extract in a Rat Model of Non-alcoholic Steatohepatitis

Oxidative stress is frequently considered as a central mechanism of hepatocellular injury in non-alcoholic steatohepatitis (NASH). The aim of this study was to investigate the effects of fermented green tea extracts (FGTE) on NASH. Rats were fed a choline-deficient high-fat diet for 4 weeks to nutritionally generate fatty livers. NASH was induced chemically by oxidative stress using repeated intraperitoneal injections of nitrite. Rats with NASH developed steatohepatitis and liver fibrosis after 6-week of such treatment. At 10 weeks, blood and liver samples were collected from anesthetized animals and assessed for extent of OS injury and effects of FGTE, by biochemical, histological and histochemical analyses. FGTE reduced serum levels of liver enzymes, lipid peroxidation and production of mitochondrial reactive oxygen species. In addition, FGTE showed inhibition of progressions of cirrhosis. Our findings suggest that our FGTE have strong radical scavenging activity and may be beneficial in the prevention of NASH progression

Beneficial effects of Vitis coignetiae Pulliat leaves on nonalcoholic steatohepatitis in a rat model

Vitis coignetiae Pulliat (Yamabudo) is used as a health juice and wine based on the abundant polyphenols and anthocyanins in its fruit. However, it is not known whether the leaves of this plant confer similar benefits. This study investigated the hepatoprotective effects of aqueous extracts from Vitis coignetiae Pulliat leaves (VCPL) in an animal model of nonalcoholic steatohepatitis (NASH). Rats were fed a choline-deficient high-fat diet for four weeks to generate fatty livers. NASH was induced by oxidative stress loading. Ten weeks later, blood and liver samples were collected from anesthetized animals and assessed biochemically, histologically, and histochemically to determine the extent of oxidative stress injury and the overall effects of VCPL. Six-week VCPL extract supplementation reduced serum levels of liver enzymes, decreased CYP2E1 induction, increased plasma antioxidant activities and delayed the progression of liver fibrosis. The findings suggested that VCPL has strong radical-scavenging activity and may be beneficial in preventing NASH progression.</p

Water Extract of Vitis coignetiae Pulliat Leaves Attenuates Oxidative Stress and Inflammation in Progressive NASH Rats

This study aimed to investigate the therapeutic effects of the water extract of leaves of Vitis coignetiae Pulliat (VCPL) on nonalcoholic steatohepatitis (NASH) with advanced fibrosis, as our previous study exhibited its preventive effect on NASH. The NASH animal model [PCT/JP2007/52477] was prepared by loading recurrent and intermittent hypoxemia stress to a rat with fatty liver, which resembled the condition occurring in patients with obstructive sleep apnea (OSA) and fatty liver, who have a high incidence of NASH. Intermittent hypoxemia stress is regarded as a condition similar to warm ischemia followed by re-oxygenation, which induces oxidative stress (OS). The daily 100 or 300mg/kg VCPL administrations were performed for 3 weeks perorally beginning at the time of detection of advanced liver fibrosis. The therapeutic efficacy of VCPL on NASH was demonstrated by the reduction of the leakage of hepato-biliary enzymes and the amelioration of liver fibrosis. The OS elevation in NASH rats was measured based on the derivation of reactive oxygen species from liver mitochondrial energy metabolism and on the decrease in plasma SOD-like activity. The aggravation of inflammatory responses was demonstrated by the neutrophil infiltration (elevated myeloperoxidase activity) and the progression of fibrosis in the livers of NASH rats. In addition, the NASH rats without VCPL treatment also exhibited activation of nuclear factor-κB, a key factor in the link between oxidative stress and inflammation. All of these changes were reduced dose-dependently by the VCPL administration. These findings indicate that VCPL may improve hepatic fibrosis or at least suppress the progression of NASH, by breaking the crosstalk between OS and inflammation

Muscarinic acetylcholine receptor M1 and M3 subtypes mediate acetylcholine-induced endothelium-independent vasodilatation in rat mesenteric arteries

The present study investigated pharmacological characterizations of muscarinic acetylcholine receptor (AChR) subtypes involving ACh-induced endothelium-independent vasodilatation in rat mesenteric arteries. Changes in perfusion pressure to periarterial nerve stimulation and ACh were measured before and after the perfusion of Krebs solution containing muscarinic receptor antagonists. Distributions of muscarinic AChR subtypes in mesenteric arteries with an intact endothelium were studied using Western blotting. The expression level of M1 and M3 was significantly greater than that of M2. Endothelium removal significantly decreased expression levels of M2 and M3, but not M1. In perfused mesenteric vascular beds with intact endothelium and active tone, exogenous ACh (1, 10, and 100 nmol) produced concentration-dependent and long-lasting vasodilatations. In endothelium-denuded preparations, relaxation to ACh (1 nmol) disappeared, but ACh at 10 and 100 nmol caused long-lasting vasodilatations, which were markedly blocked by the treatment of pirenzepine (M1 antagonist) or 4-DAMP (M1 and M3 antagonist) plus hexamethonium (nicotinic AChR antagonist), but not methoctramine (M2 and M4 antagonist). These results suggest that muscarinic AChR subtypes, mainly M1, distribute throughout the rat mesenteric arteries, and that activation of M1 and/or M3 which may be located on CGRPergic nerves releases CGRP, causing an endothelium-independent vasodilatation

Muscarinic acetylcholine receptor M1 and M3 subtypes mediate acetylcholine-induced endothelium-independent vasodilatation in rat mesenteric arteries

The present study investigated pharmacological characterizations of muscarinic acetylcholine receptor (AChR) subtypes involving ACh-induced endothelium-independent vasodilatation in rat mesenteric arteries. Changes in perfusion pressure to periarterial nerve stimulation and ACh were measured before and after the perfusion of Krebs solution containing muscarinic receptor antagonists. Distributions of muscarinic AChR subtypes in mesenteric arteries with an intact endothelium were studied using Western blotting. The expression level of M1 and M3 was significantly greater than that of M2. Endothelium removal significantly decreased expression levels of M2 and M3, but not M1. In perfused mesenteric vascular beds with intact endothelium and active tone, exogenous ACh (1, 10, and 100 nmol) produced concentration-dependent and long-lasting vasodilatations. In endothelium-denuded preparations, relaxation to ACh (1 nmol) disappeared, but ACh at 10 and 100 nmol caused long-lasting vasodilatations, which were markedly blocked by the treatment of pirenzepine (M1 antagonist) or 4-DAMP (M1 and M3 antagonist) plus hexamethonium (nicotinic AChR antagonist), but not methoctramine (M2 and M4 antagonist). These results suggest that muscarinic AChR subtypes, mainly M1, distribute throughout the rat mesenteric arteries, and that activation of M1 and/or M3 which may be located on CGRPergic nerves releases CGRP, causing an endothelium-independent vasodilatation

Effect of postprandial hyperglycemia and hyperinsulinemia on vascular responsiveness

Recent clinical studies demonstrated that transient postprandial hyperglycemia and hyperinsulinemia may contribute to the development of hypertension. Therefore, we investigated influence of acute hyperglycemia and/or hyperinsulinemia induced by glucose or insulin infusion on neuronal and humoral control of vascular tone in rats. Euglycemic male Wistar rats were pithed under anesthesia and arterial blood pressure was measured. Changes in vascular responses to spinal cord stimulation (SCS) and intravenous bolus injections of noradrenaline, angiotensin II, calcitonin generelated peptide (CGRP), acetylcholine and sodium nitroprusside (SNP) were studied by infusing various concentration of glucose or insulin. Continuous glucose infusion, which increased both blood glucose and serum insulin levels, significantly augmented adrenergic nerve-mediated pressor responses to SCS without affecting injection of pressor responses to noradrenaline or angiotensin II. In pithed rats with artificially increased blood pressure and blockade of autonomic outflow, glucose infusion attenuated CGRPergic nerve-depressor responses to SCS without affecting depressor responses to injection of CGRP, acetylcholine or SNP. In pithed rats treated with octreotide, which increased blood glucose without increasing serum insulin levels, glucose infusion caused only significant augmentation of adrenergic nervemediated pressor responses. Combined infusion of insulin and glucose, which resulted in increased serum insulin levels with euglycemic, significantly augmented adrenergic nerve-mediated pressor responses and attenuated CGRPergic nerve-mediated depressor responses. The present results suggest that acute hyperglycemia and hyperinsulinemia increases adrenergic nerve-mediated vasoconstriction, which is partly associated with the blunted CGRPergic nerve function, and that plasma insulin concentration associated with hyperglycemia may be responsible for alteration of neuronal vascular regulation

加計呂麻諸島における地域住民の生活と福祉ニーズ : 経年比較にみる一般成人調査より (1)

鹿児島県の離島である奄美大島の南部に位置している瀬戸内町は、大島本島から更に海を隔てて3つの離島を行政区に持っている。2004年の調査時において、加計呂麻島：芝地区60.91%・花富地区75.0%、請島：請阿室58.0%・池地55.7%、与路島：52.9%は超高齢社会となっており、集落の存続自体が危うい状況にあった。 8年後の2012年にこれらの地域がどのような状況になっているのか、平成26年３月に作成した調査報告書と比較検討することでみえてきた問題点・課題点、有効な対策について論述する。Setouchi Town which lies to the south of Amami Oshima is an island in Kagoshima prefecture. Setouchi Town consists of three remote islands which have administrative districts. According to the research in 2004, in Kakeroma Island, 60.91% of Shiba district and 75.0% of Kedomi district were super-aging society; in Uke Island, so were 58.0% of Ukeamuro district and 55.7% of Ikeji district; and 52.9% of Yoro Island, too. And these districts were in difficult condition to continue as villages in 2004.Comparing the above with the conditions in these districts eight years later based on the research in March, 2014, we will discuss the problems and possible measures

島嶼集落における社会的かかわり状況と見守り、防災、医療体制について : 奄美大島大和村における中高年者調査から

本研究の目的は奄美大島大和村における中高年者の社会的かかわり状況、見守り体制、災害への備え、医療体制などの現状と課題をアンケート調査により把握し、地域課題の改善に役立てることである。民生委員の協力を得た留置き調査により、40歳以上の1,240人を調査対象とし、928人から回答を得た（回収率74.8%）。近隣の交流は少し減ってきていた。社会とのかかわりでは女性の方が男性よりも高く、年齢が高くなるにつれ低くなる傾向にあった。自然な形での見守りがなされていたが、高齢になると見守り体制への要求もあった。集落の防災組織がうまく機能しているが、災害弱者や避難などへの対処に課題を残していた。医療体制については診療所への満足がある一方、緊急医療や専門医療への要望が強かった。地域の課題では買い物が不便とかハブの存在など社会的・自然的課題があった。The purpose of the study was to assess the present state of the social interaction, the supporting system, the disaster prevention measures, and the medical system in Yamato Village of Amami Oshima island. A questionnaire was personally delivered to 1240 residents of 40-year-old and above and later picked up by commissioned welfare volunteers. The number of people who responded to the questionnaire was 928 and the rate of collection was 74.8%.Neighborhood interaction decreased a little. Social interaction of women was higher than men. Social interaction of the elderly was lower than the younger. Although there were spontaneous watch activities in a natural way, the elderly hoped to have the local supporting system for them. The voluntary organizations for disaster prevention were well functioned, but there remained challenges of the measures for the vulnerable people and the emergency evacuation. With respect to the medical system, there was satisfaction with the community clinic, but on the other hand, there remained wishes regarding emergency medical system and specialized medical service. There were also social and natural problems that the shopping was inconvenient, and that the poisonous snake harmed people, and so on

島嶼集落高齢者の生きがい感に及ぼす社会関連性の影響

本研究の目的は島嶼集落に居住する高齢者の生きがい感に及ぼす社会関連性の影響を検討することである。鹿児島県の離島にある小規模自治体の高齢者に配票調査を実施し、455人の回答を分析した。生きがい感は「ふつう」レベルであり、年齢が低い方が生きがい感が高い傾向にあった。社会関連性指標の因子分析の結果、安梅（2000）と同じ5因子が見いだされた。社会関連性指標の全体の得点に性差や年齢差は見られなかった。女性の方が男性よりも得点が高いのは｢他者とのかかわり」「生活の安心感」「生活の主体性」であった。前期高齢者の方が後期高齢者よりも得点が高いのは「社会への関心」「身近な社会参加」であり、後期高齢者の方が前期高齢者よりも得点が高いのは「生活の主体性」であった。重回帰分析の結果、男女で共通して生きがい感に影響を及ぼしていた因子は「生活の安心感」「社会への関心」「生活の主体性」であった。性と年齢ともに共通して生きがい感に影響を及ぼしていた因子は「生活の主体性」であった。The purpose of the study was to investigate the effects of the indices of social interaction on the feeling that life is worth living. The questionnaire was personally delivered to the elderly who live in villages of an island in Kagoshima prefecture and picked up by commissioned welfare volunteers. The number of people who responded to the question items was 455. The level of the feeling that life is worth living was moderate, and its average score of the elderly aged 75 or over was lower than those of the young-old. Factor analysis of the social interaction measures resulted in five factors as Anme (2000) found. There was no difference related to gender or age in the total score of social interaction. Females\u27 scores of "Interaction", "Feeling of safety", and "Independence" were higher than those of males. The young-old\u27s scores of "Social curiosity" and "Participation in the society" were higher than those of the elderly aged 75 or over. The old-old\u27s score of "Independence" was higher than that of the young-old. The results of multiple regression analysis showed that for both of men and women, "Feeling of safety", "Social curiosity" and "Independence" were found respectively to affect the degrees of the feeling that life is worth living. For the respondents of both gender and age, "Independence" was relevant to the degrees of feeling that life is worth living