Fendiline mobilizes intracellular Ca2+ in Chang liver cells

1. The effects of the antianginal drug fendiline (N-[3,3-diphenylpropyl]-alpha-methyl-benzylamine) on intracellular free Ca2+ levels ([Ca2+](i)) in Chang liver cells were evaluated using fura-2 as a fluorescent Ca2+ indicator. 2. Fendiline (1-100 micromol/L) increased [Ca2+](i) in a concentration-dependent manner, with an EC50 of 25 micromol/L. 3. The [Ca2+](i) response was composed of an initial rise and a slow decay to a sustained phase. Removal of extracellular Ca2+ partly reduced the [Ca2+](i) signals. 4. Fendiline (10 micromol/L)-induced release of intracellular Ca2+ was reduced by 65% following pretreatment with 1 micromol/L thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor) to deplete Ca2+ stored in the endoplasmic reticulum. 5. After pretreatment with 10 micromol/L fendiline in Ca2+-free medium for several minutes, addition of 3 mmol/L Ca2+ induced an increase in [Ca2+](i) of a magnitude four-fold greater than control. This increase in [Ca2+](i) was not reduced by 10 micromol/L SKF96365, econazole, nifedipine or verapamil. 6. Fendiline (10 micromol/L)-induced release of intracellular Ca2+ was not altered by inhibition of phospholipase C with 2 micromol/L 1-(6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino) hexyl)-1H-pyrrole-2,5-dione (U73122). 7. The results of the present study show that fendiline induces an increase in [Ca2+](i) in Chang liver cells by releasing stored Ca2+ in an inositol 1,4,5-trisphosphate-independent manner and by causing extracellular Ca2+ influx.     

Primary porcine hepatocytes with portal vein serum cultured on microcarriers or in spheroidal aggregates

AIM:To develop a culture mode providing durable biomaterials with high yields and activities used in bioartificial liver.METHODS:Hepatocytes were isolated from a whole pig liver by Seglen s method of orthotopic perfusion with collagenase. In culture on microcarriers, primary porcine hepatocytes were inoculated at a concentration of 5center dot10(7)/mL into the static culture systems containing 2g/L Cytodex-3, then supplemented with 100mL/L fetal calf serum (FCS) or 100mL/L porcine portal vein serum (PPVS) respectively. In spheroidal aggregate culture hepatocytes were inoculated into 100mL siliconized flasks at a concentration of 5.0center dot10(6)/mL.RESULTS:In culture on microcarriers hepatocytes tended to aggregate on Cytodex-3 obviously after being inoculated. Typical multi-cellular aggregated spheroids could be found in the two systems 24h-48h after hepatocytes were cultured. The morphological charact-eristics and synthetic functions were maintained for 5wk in FCS culture system and 8wk in PPVS culture system. In spheroidal aggregate culture about 80%-90% isolated hepatocytes became aggregated spheroids 24h after cultured in suspension and mean diameter of the spheroids was 100&mgr;m. The relationship among the hepatocytes resembled that in the liver in vivo. Synthetic functions of albumin and urea of the spheroids were twice those of hepatocytes cultured on monolayers.CONCLUSION:As high-yields and high-activity modes of culture on microcarriers or in spheroidal aggregate culture with portal vein serum are promising to provide biomaterials for bioartificial liver (BAL) efficiently.     

预诱导提高成年动物肝细胞胆红素代谢活性

目的 探讨经苯巴比妥钠(phenobarbital sodium,PBS)体内预诱导的成年动物肝细胞(adult animal hepatocytes,AAH)在体外时能否提高对胆红素的代谢活性,为体外生物人工肝支持系统(extracorporeal bioartificial liver support system,EBLSS)寻求更佳的生物材料.方法 12只成年雄性小白鼠平均体重34g,随机分为预诱导组与对照组各6只,预诱导组每日1次腹腔内注射PBS 45mg/kg,共5次,对照组注射NS,末次给药的24h后取肝脏;从同组的每只实验鼠中各取湿重肝0.5g混合,合并研制为混悬液加入96孔培养板每孔30μl,各孔再加入黄疸血清50μl,最后加培养液20μl,使各孔终体积为100μl,每组设6孔,共两组12孔;同时设无肝细胞的黄疸血清孔做两组的对照,共同在37℃、95%湿度、5%CO2培养箱中静置培养3h后离心,取上清用贝克曼生化分析仪检测两组的胆红素变化.结果 与对照血清比较,预诱导组总胆红素、间接胆红素各下降60%、71.42%,直接胆红素无显著变化;对照组总胆红素、间接胆红素各下降34.78%、54.87%,直接胆红素亦无显著变化;两组总胆红素变化比较P＜0.05(t=2.899),间接胆红素变化比较P＞0.05(t=1.571).结论 体内PBS预诱导可增强AAH在体外对胆红素的代谢活性,预诱导的AAH可能是EBLSS更佳的生物材料.     

Interleukin-6 alters the cellular responsiveness to clopidogrel, irinotecan, and Oseltamivir by suppressing the expression of Carboxylesterases HCE1 and HCE2

Carboxylesterases constitute a class of enzymes that play important roles in the hydrolytic metabolism of drugs and other xenobiotics, patients with liver conditions such as cirrhosis show increased secretion of proinflammatory cytokines [e. g., interleukin-6 （IL- 6）] and decreased capacity of hydrolysis. In this sfudy, we provide a molecular explanation linking cytokine secretion directly to the decreased capacity of hydrolytic biotransformation. In both primary hepatocytes and HepG2 cells, treatment with IL-6 decreased the expression of human carboxylesterases HCE1 and HCE2 by as much as 60%. The decreased expression occurred at both mRNA and protein levels, and it was confirmed .by enzymatic assay. In cotransfection experiments, both HCE1 and HCE2 promoters were significantly repressed, and the repression was comparable with the decrease in HCE1 and HCE2 mRNA, suggesting that transrepression is responsible for the suppressed expression. In addition, pretreatment with IL-6 altered the cellular responsiveness in an opposite manner of overexpression of HCE1 and HCE2 toward various ester therapeutic agents （ e. g., clopidogrel）. Transfection of HCE1, for example, decreased the cytotoxicity induced by antithrombogenic agent clopidogrel, whereas pretreatment with IL-6 increased the cytotoxicity. Such a reversal was observed with other ester drugs, including anticancer agent irinotecan and anti-influenza agent oseltamivir. The altered cellular responsiveness was observed when drugs were assayed at sub-and low-micromolar concentrations, suggesting that suppressed expression of carboxylesterases by IL-6 has profound pharmacological consequences, particularly with those that are hvdrolvzed in an isoform-specific manner.     

Apoptosis of neoplasm cell lines induced by hepatic peptides extracted from sucking porcine hepatocytes

lNTRODUCTlONPromotinghepatocytegr0wthfact0r(pHGF)extractedfromthesuckingpigliverisaseriesofpolypeptideswithmolecularweightlessthanM,100O0andhasspecificbiol0gicalactivitiest0stimulatetherathepatocyteDNAsynthesisafter1/3partialhepatectomyandpromoterecoveryofrathepaticinjuriesinducedbyend0toxinandD-aminogalatose.ThesepropertiesaresimilartotheresultsreportedbyLabrecque['].pHGFcaneffectivelycureclinicalacutefulminanthepatitis,chronichepatitisand0therhepaticinjuriesbysignificantlyreducingser…     

Cytotoxicity of aged cadmium-telluride quantum dots to rainbow trout hepatocytes

The purpose of this study was to examine the lethal and sublethal toxicity of cadmium telluride (CdTe) quantum dots (Q-dots) in primary cultures of rainbow trout hepatocytes. Hepatocytes were exposed to concentrations of positively coated and aged (2 months and 2 years) Q-dots for 48 h at 15°C. Post treatment, cellular analysis was done of cell viability, lipid peroxidation (LPO), DNA damage, metallothioneins (MT), labile zinc/cadmium and heat shock proteins (chaperones). Q-dots were found to be toxic to fish hepatocytes at a threshold concentration of 0.1 mg/l. These nanoparticles increased the levels of MT, labile zinc, DNA strand breaks and heat shock proteins of the 70 kDa family. The strongest response was observed with the molecular chaperone of the 70 kDa family, reaching a 7-fold induction in exposed cells. Overall, the assessment of multiple biomarkers in trout hepatocytes exposed to differently ‘aged’ Q-dots suggests that the cytotoxic responses to two-year-old positively coated CdTe Q-dots were largely due to the liberation of Cd²⁺.     

Automated morphometric evaluation of structure of nuclear chromatin of liver cells after vagotomy

Laboratory of Cytology, Research Institute of Physicochemical Medicine, Ministry of Health of the RSFSR, Moscow. Department of Histology, Faculty of Internal Medicine, N. I. Pirogov Second Moscow Medical Institute. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 107, No. 5, pp. 637–639, May, 1989.     

Cyanamide hepatotoxicity. Incidence and clinicopathological features

ABSTRACT— Ground-glass hepatocytes resembling those seen in HBsAg carriers on hematoxylin and eosin and on trichrome stained sections, but giving a negative reaction to orcein and a positive one to PAS, were found in liver biopsy specimens from nine asymptomatic former alcoholics who were on treatment with cyanamide, in one of four who had been treated with cyanamide several months before the liver biopsy procedure, in none of 15 treated with disulfiram, and in one of eight who had apparently not received aversive drugs. Portal and periportal inflammatory changes and fibrosis were more frequently observed in biopsy specimens containing PAS-positive ground-glass hepatocytes than in those without, but cirrhosis was found with a similar frequency. It is concluded that periportal PAS-positive ground-glass hepatocytes are a histological marker of cyanamide treatment.     

移植胎肝细胞在体内分布和存活的示踪观察

我们观察了胎肝细胞的在体同位素标记及其影响因素;同时应用同位索标记的胎肝细胞,观察了胎肝细胞移植后在受体体内的分布格局和存活情况及其一些影响因素。实验发现,经胎鼠腹腔注射,~(125)I-UdR时,胎肝摄取~(125)I-UdR最多。标记胎肝细胞经外周静脉注射给成年小鼠后,主要分布在肺和肝中,这种分布格局受注射胎肝细胞数量和速度的影响。结果提示:在体法同位素标记的胎肝可用于胎肝细胞移植研究。