Acute hepatotoxicity and lethality of CCl4 in chlordecone-pretreated rats

In a subchronic dietary pretreatment protocol chlordecone (CD) is a powerful potentiator of CCl4 hepatotoxicity, as indicated by biochemical, hepatofunctional, histopathological, and lethality parameters. The purpose of this investigation is to further explore the CD + CCl4 interaction in an acute CD pretreatment protocol and to compare the two pretreatment protocols in terms of their effect upon quantitative histopathology, serum enzymes, and lethality. Groups of four male rats received one of the following four pretreatments: chlordecone (10 mg/kg; single po), mirex (10 mg/kg; single po), phenobarbital (PB) (80 mg/kg/day for 2 successive days; ip in 0.9% saline), or corn oil vehicle (1 ml/kg; single po). Twenty-four hours later, the rats were given a single ip injection of CCl4 (0.1 ml/kg). Twenty-four hours after CCl4 administration, serum enzymes (SGPT, SGOT, and ICD) were measured and the livers removed and fixed in 10% buffered formalin for histological evaluation. The LD50 were determined by the method of moving averages. CD + CCl4 was the most hepatotoxic combination, in terms of serum enzyme elevations and lethality followed by PB + CCl4. The PB + CCl4 combination caused a greater degree of hepatocyte necrosis. These findings indicate that the acute pretreatment with CD enhances hepatotoxicity and the lethality of CCl4 in a fashion qualitatively similar to the subchronic pretreatment protocol.     

Hematological and blood pressure studies in the CCl4 treated rats

Hematological parameters were studied in normotensive and spontaneous hypertensive rats along with those treated with chronic subcutaneous injections of CCl4. The normotensive animals treated with CCl4 demonstrated an erythrocytosis with an increase in the hematocrit levels. A lymphocytosis was seen with neutropenia in both CCl4 treated and untreated normotensive groups. The SHR animals compared to their normotensive counterparts had a lesser degree of lymphocytosis with an increase in the number of neutrophils. There was no blood pressure change in the normotensive CCl4 treated group, however a significant blood pressure difference was observed in the SHR group after CCl4 treatment.     

Pivotal role of hepatocellular regeneration in the ultimate hepatotoxicity of CCl4 in chlordecone-, mirex-, or phenobarbital-pretreated rats.

Our earlier histomorphometric and biochemical studies suggested that the progressive phase of the interactive toxicity of chlordecone (CD) + CCl4 involves suppression of hepatocellular regeneration. The objective of the present work was to correlate hepatocellular regeneration with CCl4 (100 microliters/kg)-induced hepatotoxicity in rats maintained for 15 days on a normal (N) diet, relative to the regenerative response in rats maintained on a diet containing either 10 ppm CD, 225 ppm phenobarbital (PB), or 10 ppm mirex (M). Hepatocellular regeneration was assessed by measuring DNA and 3H-thymidine (3H-T) incorporation, followed by autoradiographic analysis of liver sections. Hepatotoxicity was assessed by measuring plasma transaminases (aspartate and alanine) followed by histopathological observations of liver sections for necrotic, swollen, and lipid-laden cells. Lethality studies were also carried out to assess the consequence of hepatotoxicity on animal survival. Dietary 10 ppm CD potentiated the hepatotoxicity of CCl4 to a greater extent than PB or M, as evidenced by elevations in plasma enzymes. Although the serum enzymes were significantly elevated in PB rats in contrast to the slight elevations in N and M rats, they returned to normal levels by 96 hr. However, serum enzyme elevations in CD rats were progressive with time until death of the animals. Actual liver injury by CCl4 was greater in PB- than in CD-pretreated rats, as evidenced by histopathological observations. A 100% mortality occurred in CD-pretreated rats at 60 hr after CCl4 administration, whereas no mortality occurred in either N-, M-, or PB-pretreated rats, indicating recovery from liver injury. Hepatocellular nuclear DNA levels were significantly decreased starting at 6 hr after CCl4 administration to CD-pretreated rats, but not in M- or PB-pretreated rats. 3H-T incorporation into nuclear DNA as well as percentage of labeled cells showed a biphasic increase in N rats: 1 at 1-2 hr, and the other at 36-48 hr after CCl4 administration. However, only 1 peak of 3H-T incorporation at 36-48 hr was observed in the CD + CCl4 combination, which was also significantly lower when compared to that observed after the M or PB + CCl4 combination treatments. These findings suggest that there is recovery in N-, PB-, or M-pretreated rats from CCl4-induced injury by virtue of the stimulated hepatocellular regeneration and tissue repair.(ABSTRACT TRUNCATED AT 400 WORDS)     

Retinol binding protein 4 correlates with and is an early predictor of carotid atherosclerosis in type 2 diabetes mellitus patients

The association of retinol binding protein 4 (RBP4) with atherosclerosis of the carotid artery in type 2 diabetes mellitus (T2DM) remains undefined. We aimed to investigate the correlation of RBP4 expression with atherosclerosis of the carotid artery in T2DM. A total of 1,076 subjects were investigated for intima-media thickness of the bilateral common carotid arteries, and they were divided into three groups: in group I, patients had normal neck vascular ultrasound, in group II, intimal carotid artery media thickness was equal to or more than 1 mm, and in group III, carotid artery plaque was present. Height, weight, blood pressure (BP), fasting plasma glucose (FPG), hemoglobin A1c (HbA1c), total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), apolipoprotein A-1 (apoA-1), apolipoprotein B (apoB) and lipoprotein (a) [Lp(a)] were determined by routine laboratory methods. RBP4 and high sensitivity C reactive protein (HsCRP) were measured by an enzyme-linked immuno-sorbent assay, and insulin concentration was measured by an electrochemiluminescence sandwich immunoassay. Duration of diabetes, waist and BP, FPG, HbA1c, TG, TC, LDL-C, APOB, Lp(a), HsCRP, RBP4 and homeostasis model assessment insulin resistance index (HOMA-IR) were significantly lower in group I than in the other two groups (P<0.01, P<0.01). Plasma levels of HbA1c, RBP4, LDL-C, TC, HOMA-IR, HsCRP and Lp(a), waist and BP were significantly increased in group III than in group II (P<0.01). Multivariate logistic regression analysis showed that there were seven factors associated with the occurrence of carotid artery atherosclerosis and its risks in descending order were: high LDL-C, high waist, high HsCRP, duration of diabetes, high HOMA-IR, HbA1c and high RBP4. Our finding supported that RBP4 was positively correlated with carotid atherosclerosis in patients with T2DM and could be used as an early predictor of cardiovascular disease.     

Retinol binding protein 4 as a candidate gene for type 2 diabetes and prediabetic intermediate traits

Serum retinol binding protein 4 (RBP4) was recently described as a new adipokine that reduced peripheral and hepatic insulin sensitivity and increased hepatic gluconeogenesis. The RBP4 gene maps to 10q23-24, near a region linked to T2DM in Caucasian and Mexican American populations. Hence, sequence variants that alter RBP4 expression or function could increase T2DM susceptibility and reduce insulin sensitivity. We screened the 6 exons, flanking intronic sequence, and 5' and 3' flanking sequences in 48 Caucasian and 48 African American subjects. We identified 21 SNPs, of which 8 were unique to the African American population. Additional public database SNPs were chosen for regions not screened. We selected SNPs for typing based on frequency, linkage disequilibrium, and location in a putative functional or conserved region. We typed 10 SNPs in 191 Caucasians with T2DM and a family history of T2DM, and 188 euglycemic controls with no family history of diabetes. We similarly typed 14 variants in 182 controls and 353 diabetic individuals of African American ancestry. No single variant was associated with type 2 diabetes in either population (p>0.15 in African Americans, p>0.09 in Caucasians), but a haplotype of 8 common SNPs in Caucasians was significantly increased in type 2 diabetics compared with controls (0.137 vs. 0.076, p=0.008). Furthermore, SNPs -804 and +9476 were associated with reduced insulin secretion, (p=0.01 and 0.001, respectively), and SNP +390 with reduced insulin sensitivity (p=0.0005) in Caucasians. Our data suggest that noncoding SNPs may increase diabetes susceptibility in Caucasians and may contribute to insulin resistance and reduced insulin secretion.     

Polyploidization of hepatocytes in rats following exposure to CCl4 under different conditions

A karyometric study was made of hepatocyte polyploidization in albino rats during continuous and interrupted poisoning with CCl₄. Polyploidization, as a response to exposure to chlorinated hydrocarbons, was shown to depend on the toxicity of the poison, which depends on the number of chlorine atoms in the molecule, and on the character of exposure (mode of administration, dose, regime).Laboratory of Morphology, A. N. Sysin Institute of General and Communal Hygiene, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. M. Chernukh.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 89, No. 1, pp. 57–59, January, 1980.     

四氯化碳致大鼠、小鼠肝损伤的对比实验

人们习惯将CCl4 致肝损伤模型作为筛选具有保肝降酶作用药物的常用模型之一[1～ 3] 。常用实验动物为大鼠及小白鼠 ,以血清转氨酶为观察指标来评价被筛选药物的保肝降酶效果。我们在最近筛选保肝药物的实验中发现 ,用CCl4 所致的肝损伤模型动物小白鼠的血清转氨酶量存在很大的个体差异。为此我们对比了CCl4 致大鼠、小鼠肝损伤实验 ,就CCl4 致动物肝损伤的稳定性进行了探讨。1　实验材料1 1　药品和试剂 :四氯化碳 (CCl4 ,分析纯 ,济南化工厂生产 ) ,根据需要用纯花生油配成不同浓度 ;谷丙转氨酶试剂盒(购自北京中国生化药品公司 )。1 2…     

肝纤维化大鼠转化生长因子β1／Smad蛋白的动态表达及意义

目的探讨转化生长因子TGF—β1／Smad信号通路在实验性肝纤维化发生中的作用。方法50只健康雄性SD大鼠分为2组：正常组和模型组,模型组大鼠利用40％CCl4油剂诱导形成肝纤维化模型,于6周及9周观测肝标本的病理,免疫组化法检测肝组织TGF—β1／Smad蛋白表达。结果①肝组织病理：与正常组比较,模型组大鼠肝组织都有不同程度的炎症和纤维化产生。模型组纤维化程度较正常对照组明显,差异有统计学意义（P〈0．05）;②TGF—β1／Smad基因蛋白：免疫组织化学检测显示,与正常对照组相比,模型组大鼠肝脏中TGF—β1、转化生长因子βI型受体（TβR—I）、Smad2、3、Smad,蛋白表达均显著增强（P〈0．01）,模型组大鼠肝脏TGF—β1、TβR-I、Smad。和Smad,之间存在正相关关系（P〈0．05或0．01）;模型组大鼠肝脏纤维化分级与TGF—β1、TβR—I、Smad2/3和Smad,之间存在正相关关系（P〈0．05或0．01）。结论肝组织TGF—β1／Smad蛋白表达水平与肝纤维化程度相关,TGF-β1／Smad信号的增强可能促进了肝纤维化的进展。     

Hepatoprotection with a chloroform extract of Launaea procumbens against CCl4-induced injuries in rats

ABSTRACT: BACKGROUND: Launaea procumbens (Asteraceae) is used as a folk medicine to treat hepatic disorders in Pakistan. The effect of a chloroform extract of Launaea procumbens (LPCE) was evaluated against carbon-tetrachloride (CCl4)-induced liver damage in rats. METHODS: To evaluate the hepatoprotective effects of LPCE, 36 male Sprague-Dawley rats were equally divided into six groups. Animals of group 1 (control) had free access to food and water. Group II received 3 ml/kg of CCl4 (30% in olive oil v/v) via the intraperitoneal route twice a week for 4 weeks. Group III received 1 ml of silymarin via gavage (100 mg/kg b.w.) after 48 h of CCl4 treatment whereas groups IV and V were given 1 ml of LPCE (100 and 200 mg/kg b.w., respectively) after 48 h of CCl4 treatment. Group VI received 1 ml of LPCE (200 mg/kg b.w.) twice a week for 4 weeks. The activities of the antioxidant enzymes catalase, peroxidase (POD), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione S-transferase (GST), glutathione reductase (GSR), glutathione (GSH) and lipid peroxidation (thiobarbituric acid reactive substances (TBARS)) were measured in liver homogenates. DNA damage, argyrophilic nucleolar organizer regions (AgNORs) counts and histopathology were studied in liver samples. Serum was analyzed for various biochemical parameters. Phytochemical composition in LPCE was determined through high-performance liquid chromatography (HPLC). RESULTS: LPCE inhibited lipid peroxidation, and reduced the activities of aspartate transaminase, alanine transaminase, alkaline phosphatase, and lactate dehydrogenase in serum induced by CCl4. GSH contents were increased as were the activities of antioxidant enzymes (catalase, SOD, GST, GSR, GSH-Px) when altered due to CCl4 hepatotoxicity. Similarly, absolute liver weight, relative liver weight and the number of hepatic lesions were reduced with co-administration of LPCE. Phyochemical analyses of LPCE indicated that it contained catechin, kaempferol, rutin, hyperoside and myricetin. CONCLUSION: These results indicated that Launaea procumbens efficiently protected against the hepatotoxicity induced by CCl4 in rats, possibly through the antioxidant effects of flavonoids present in LPCE. KEYWORDS: Launaea procumbens, hepatic injuries, flavonoids, antioxidant enzymes, carbon tetrachloride.     

Aggravation of injury to liver lysosomes of rats with CCl4 hepatitis by preliminary prolonged administration of chlorpromazine

Preliminary prolonged administration of chlorpromazine (5 mg/kg for three weeks) aggravated the injury to liver lysosomes of rats with acute CCl₄ hepatitis. Similar marked changes were observed in lysosomes sedimented with heavy and light mitochondrial fractions.Central Scientific-Research Laboratory and Department of Psychiatry, Novosibirsk Medical Institute. (Presented by Academician, of the Academy of Medical Sciences of the USSR V. P. Kaznacheev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 1, pp. 38–41, January, 1977.     

Hepatoprotective effects of prostacyclins on CCl4-induced liver injury in rats

Certain biochemical parameters of acute liver injury induced by carbon tetrachloride were investigated in rats treated with prostacyclin (PGI2) and two of its derivatives. Serum glutamate oxalacetate transaminase elevation and both triglyceride accumulation and reduction of glycogen content in liver were significantly suppressed by PGI2, 7-oxo-PGI2, and 20-methyl-13,14-didehydro-2,4-m-interphenylene-PGI2 48 hr after the injury. Prostacyclins partially restored some of the parameters of injury even in doses of 10 micrograms/kg ip. When the compounds were given 24 hr after CCl4 intoxication, much more pronounced protection was observed than in the case of treatments 1 hr before administration of the hepatotoxin. Thus, all tested prostacyclins exerted significant protective effects on acute liver damage which is obtained mainly in the second phase of the injury.     

卵巢切除对四氯化碳诱导大鼠肝纤维化形成的影响

为探讨卵巢切除对CCl4 诱导大鼠肝纤维化形成的影响 ,采用CCl4 诱导雌性大鼠肝纤维化动物模型 ,观察卵巢切除及雌激素替代治疗 (苯甲酸雌二醇 1mg kg)对肝脏胶原沉积和I、Ⅲ型胶原蛋白表达的影响 ,并分别检测血清学标志及肝脏组织学等变化。结果显示CCl4 模型组大鼠肝脏发生典型的肝纤维化改变 ,卵巢切除组的肝脏胶原沉积更为明显 ,肝脏表达I、Ⅲ型胶原及血清肝纤维化指标也明显高于CCl4 摸型组 (P <0 0 5 ) ,而雌激素干预及替代治疗则可抑制肝纤维化的形成。表明卵巢切除加速CCl4 诱导大鼠肝纤维化的形成 ,其发生可能与卵巢分泌的雌激素对肝纤维化的抑制作用有关。     

羟基红花黄色素A对四氯化碳致大鼠肝纤维化的干预作用

目的:探讨羟基红花黄色素A(HYSA)对四氯化碳(CCl4)诱导的大鼠肝纤维化(HF)形成的影响及其机制.方法:清洁级雄性SD大鼠随机分为模型组、红花注射液组、HYSA组和秋水仙碱组,腹腔注射给药,8周后取材,放射免疫技术检测血清纤维化指标透明质酸(HA)、层黏蛋白(LN)、Ⅲ型前胶原(PC-Ⅲ)、Ⅳ型胶原(CⅣ),Masson三色染色观察胶原纤维面积比变化,Hoechest 33342染色荧光显微镜观察肝细胞凋亡情况,免疫组织化学法检测肝组织基质金属蛋白酶组织抑制因子(TIMP-1)的表达情况.结果:与生理盐水组比较,红花注射液组、HYSA组和秋水仙碱组大鼠血清HA、LN、PCⅢ、CⅣ的含量降低,大鼠肝组织胶原纤维增生程度减轻,细胞变性、坏死减少,TIMP-1表达减少.结论:HYSA具有抗大鼠肝纤维化的作用,其机制可能与减少TIMP-1的表达有关.     

四氯化碳诱导的肝损伤对大鼠免疫机能的影响

目的:研究化学性肝损伤对机体免疫机能的影响。方法:选择30只健康、1月龄、平均体重(83.20±2.11) g雌雄各半SD大鼠,经一段时间适应性饲养后,随机分成四氯化碳(CCl₄)注射组和对照组。CCl₄注射组大鼠按0.2 mL/100 g体重剂量每周定时注射CCl₄ 2次, 连续注射8周;对照组同时注射等量的橄 榄油。观察CCl₄诱导的肝损伤对机体免疫功能的影响。结果:注射CCl₄大鼠外周血T淋巴细胞比例和白细胞介素2水平显著低于对照组,与此同时B淋巴细胞比例却显著高于对照组;注射CCl₄组大鼠血浆总蛋白含量和白蛋白、α和β球蛋白比例下降,而γ球蛋白上升。结论:CCl₄诱导的肝损伤能明显影响大鼠的细胞免疫和体液免疫功能,造成大鼠的免疫功能失调。