ISCOMS重组乙型肝炎疫苗的研究

目的　提高CHO细胞表达的重组乙型肝炎病毒表面抗原 (HBsAg)的免疫原性。方法　采用透析法制备HBsAg免疫刺激复合物 (immunostimulatingcomplexes简称ISCOMS)。用放免法 (RIA)检测免疫小鼠的抗体滴度 ;标记胸腺嘧啶掺入法 (3H TdR)检测小鼠脾淋巴细胞转化率 ;CTLL 细胞株 XTT法检测IL 2活性。结果　经电镜观察ISCOMS颗粒呈蜂窝状 ,直径为 30～ 4 0nm左右。SDS PAGE分析 ,制备的ISCOMS颗粒HBsAg蛋白均由P2 3、GP2 7和GP30组成。用Bradfords法测定ISCOMS蛋白回收率为 4 1 5 0 %。免疫NIH小鼠结果显示ISCOMS重组乙肝疫苗和铝佐剂疫苗的ED50 分别为 10 3 2 2 5 5和 2 5 80 6 4 ;ISCOMS组的相对效力是铝佐剂组的 4倍。刺激指数 (SI)分别为 6 78± 2 32和 3 12± 0 5 4。IL 2水平分别是 10 2IU ml± 2 12IU ml和 4 95IU ml± 0 86IU ml。结论　ISCOMS重组乙型肝炎疫苗稳定性好 ,免疫原性强 ,抗体产生早 ,滴度高 ,并且能激起细胞免疫 ,有可能发展成为新一代疫苗。     

不同采食方式对昆明小鼠寿命的影响

目的　观察不同采食方式对昆明小鼠寿命的影响。方法　在昆明小鼠繁殖群中 ,随机抽取 180只2 1日龄雌雄各半小鼠 ,根据不同采食方式分成 3个组 ,观察其寿命长短。结果　正常采食组平均寿命 (5 82 5 0±177 73)d ,限食采食组平均寿命 (730 2 5± 16 7 39)d ,自由采食组平均寿命 (5 4 8 75± 14 8 6 6 )d。总体平均 (6 2 0 0 0±16 4 5 9)d。自由采食组与正常采食组差异无显著意义 (P >0 0 5 ) ,限食采食组比自由采食组和正常采食组寿命长 ,且差异有显著意义 (P <0 0 0 1)。雄性鼠比雌性鼠寿命长 ,且差异有显著意义 (P <0 0 0 1)。结论　采食方式明显影响昆明小鼠的寿命     

双启动子对增强型绿色荧光蛋白表达的影响

目的研究双启动子对增强型绿色荧光蛋白(EGFP)表达的影响及双启动子的启动效率。方法分别将H1、U2、U3和U6启动子克隆至pEGFP-N1载体中的MCS位点处,构建CMV与以上各个启动子的双启动子表达载体。将重组载体转染293T细胞,荧光显微镜观察,流式细胞术检测转染效率及EGFP基因的表达效率(以荧光指数表示)。结果双启动子重组表达载体经PCR和酶切证明构建正确。流式细胞术检测表明,pEGFP-N1载体与分别插入H1、U2、U3和U6启动子的双启动子重组表达载体的转染效率分别为26.57%±1.54%、28.57%±0.99%、16.14%±1.69%、22.63%±1.77%和17.89%±1.84%;EGFP基因的表达效率分别为142.79±31.26、103.59±25.90、19.67±0.52、58.16±14.58和15.40±1.92。结论CMV与H1启动子联合驱动EGFP的表达效果与CMV单独驱动相近,而CMV分别与U2、U3和U6启动子联合驱动EGFP的表达效果显著低于CMV单独驱动。     

Ⅰ型糖尿病模型大鼠在重复给药毒性试验中的应用

目的研究Ⅰ型糖尿病模型大鼠在精蛋白重组人胰岛素注射液重复给药毒性试验中的应用。方法使用链脲佐菌素(streptozocin,STZ)对健康SD大鼠造模,55 mg/kg,计算6个月后的存活率。取模型大鼠,分高、中、低剂量(30、12、5 U/kg)组和对照组,每组20只,雌雄各半,高、中、低剂量组给予精蛋白重组人胰岛素注射液,对照组给予精蛋白重组人胰岛素注射液辅料空白液,均经大鼠皮下注射,1次/d,连续4周,进行重复给药毒性试验,给药4周后,经大鼠腹主动脉采血,检测血清胰岛素含量、C肽含量、糖化血红蛋白含量以及血液生化学和血液细胞学相关指标,并进行组织病理学观察。结果模型大鼠血糖均高于16.7 mmol/L,建模成功率为91.7%,6个月存活率为82%,确定建模成功。重复给药毒性试验高剂量组大鼠死亡4只。与其他剂量组相比,给药结束后和恢复期结束后高剂量组大鼠血清中糖化血红蛋白降低(P0.05);与对照组相比,给药结束后,胰岛素、C肽含量升高(P0.05),恢复期结束后,高、中剂量组胰岛素、C肽含量升高(P0.05);与对照组相比,给药结束后,高剂量组雄鼠和雌鼠血清中白蛋白、血小板升高(P0.05),淋巴细胞数降低(P0.05),而雌鼠红细胞、白细胞减少(P0.05),其余血液细胞学指标未见明显差异。恢复期结束后,各剂量组血液生化学和血液细胞学指标均无差异,建模成功大鼠主要脏器均出现病理变化,重复给药毒性试验中各组大鼠各主要脏器在给药结束后和恢复期结束后也分别出现不同程度的病理变化。结论用STZ造模的Ⅰ型糖尿病大鼠对于精蛋白重组人胰岛素产生的低血糖反应具有较好的耐受性,接近于临床患者的病理生理特征,在使用精蛋白重组人胰岛素进行重复给药毒性试验中具有实际应用价值。     

聚乙二醇化重组人干扰素α2b的质量检测

目的　建立聚乙二醇化重组人干扰素α2b(PEG rhIFNα2b)的质量检测方法。方法　采用Wish细胞 VSV病毒系统 ,以CPE法测定干扰素的生物学活性 ,基质辅助激光解吸附飞行时间质谱法测定相对分子质量 ,反向高效液相法 (RP HPLC)测定纯度 ,溴化氰裂解 SDS PAGE法测定肽图 ,等电聚焦电泳法测定等电点 ,紫外分光光度法测定紫外吸收光谱。结果　聚乙二醇化重组人干扰素α2b的比活为 6 . 0× 10 6～ 10 . 0× 10 6IU/mg蛋白 ,相对分子质量约为 6 2 6 0 0 ,等电点在 5 . 2 0～ 6. 5 5之间 ,紫外最大吸收峰约在 2 78nm波长处。结论　所建立的检测方法可控制聚乙二醇化重组人干扰素α2b质量。     

吸附法处理石油污水中COD的实验研究(Ι)--吸附剂及吸附条件的选择

从 2 0余种对石油污水中COD类污染物具有吸附功能的物质中遴选出了蛭石、蛇纹石、膨润土 3种吸附剂。在装有粒度 0 .2 6mm的 10 0g吸附剂的=30mm ,H =6 0 0mm吸附柱上 ,控制污水流速为 2mL/min ,污水在吸附柱上停留时间 2h,对 10L (5 0± 5 )℃的中性 (pH =7.0± 0 .5 )石油污水中COD的降低效果是 :蛭石为 86 .8% ,蛇纹石为 81.5 % ,膨润土为 6 5 .1%。     

GB 19340-2003《鞋和箱包用胶粘剂》国家标准发布

GB 19340— 2 0 0 3是强制性国家标准 ,规定了鞋和箱包用胶粘剂的粘接性能指标、试验方法和有害物质限量。对于有害物质限量的要求比GB 185 83— 2 0 0 1标准更严格 ,增加了对卤代烃和正己烷的限制。现对新标准予以简要介绍。粘接性能指标初粘性 [粘合后 2min ,剥离强度 (2 3± 2 )℃ ],≥ 1.0kN·m-1;剥离强度 [(2 3± 2 )℃ ,相对湿度 5 0± 5 %条件下停放 5d],≥ 4 .0kN·m-1;耐热老化性 [在 (5 0± 2 )℃停放 7d后的剥离强度 ],≥ 4 .0kN·m-1;剪切强度 ,≥ 1.8MPa ;蠕变性 [(5 0± 2 )℃ ,1.5kg ,10min],≤ 15mm。有害物质限量指标…     

2.5sNGF酶联免疫检测试剂盒的研制

用成年雄性小鼠颌下腺提纯的 2 5sNGF免疫家兔得到兔抗NGF抗体 ,研制出 2 5sNGFELISA试剂盒。经检测本试剂盒灵敏度达到 1ng ml,在 0 84～ 6 7ng ml范围内线性良好 (r >0 99)。对人、小鼠、大鼠血浆无非特异反应 ,在大鼠血浆中NGF样品回收率在 91%～ 10 7%之间 ,变异系数小于 10 % (n =4)。对NGF参比品进行 6次标定 ,平均值为 13 4± 1 13ng 支 ,板间CV为 8 43% (n =6 ) ,板内CV值均小于 6 % (n =4,3次 )。表明本试剂盒可用于小鼠 2 5sNGF制品的定量检测和药代动力学研究。     

风神轮胎股份有限公司成功研制出新规格宽基工程机械轮胎

风神轮胎股份有限公司继 2 0 0 3年 2月成功研制出 2 3.5 - 2 5 1 6PRG 2 6混合花纹宽基工程机械轮胎后 ,又研制出 35 /65 - 3330PRG 2 4无内胎宽基工程机械轮胎。　　 2 3.5 - 2 5 1 6PRG 2 6混合花纹宽基工程机械轮胎主要为ZL 5 0型装载机及其它同类型机械配套 ,也用于多种条件下作业的推土机和挖掘机 ,具有胎体坚固耐用、承载能力高、花纹独特美观的特点。该规格轮胎采用 1 9.5 0 /2 .5标准轮辋 ,新轮胎充气断面宽为 ( 5 95± 2 0 82 )mm ,外直径为 ( 161 5± 2 4 2 3)mm ,速度为 8km·h- 1 、气压为 32 0kPa时载荷为 9470 0kN。…     

用自动系统凯氏定氮仪测定生物制品中蛋白质含量

应用自动系统凯氏定氮仪测定人血白蛋白和人血丙种球蛋白的蛋白含量 ,重复性测定X % (n =10 )±SD分别为 2 0 45 %± 0 18%和 10 2 5 %± 0 12 % ;用硫酸铵、氨基乙酸和标准蛋白质控液作回收率试验R % (n =10 )±SD分别为 10 0 .2 4%± 0 5 7% ,99.89%± 0 43%和 10 0 5 0 %± 0 75 % ;用该法测定蛋白质含量与手工定氮法比较有良好相关性 ,总氮 (TN)相关系数r(n =2 6 )为 0 9999;非蛋白氮 (NPN)r(n =19)为 0 9946 ;蛋白氮 (PN)r(n =19)为 0 .9999。测定同批标准人血白蛋白 ,结果X % (n =2 0 )±SD为 5 5 3%± 0 14% ,与其参考标准值 5 5 4%± 0 12 %非常接近。因此 ,用该仪器法测定生物制品中的蛋白质含量准确可靠 ,且快速。     

链脲佐菌素诱导的雄性大鼠高血糖对子代生长发育及代谢的影响

目的观察链脲佐菌素(Streptozocin,STZ)诱导的雄性大鼠高血糖对子代生长发育及代谢的影响。方法将健康雄性SD大鼠随机分为对照组(CON)和STZ组,STZ组经腹腔注射STZ(35 mg/kg)建立雄性大鼠糖尿病模型,CON组经腹腔注射pH 4.2的枸橼酸钠缓冲溶液。两组雄鼠分别与健康SD雌鼠按1∶2比例交配。雌鼠分娩后,称量两组子代出生体重,并连续监测体重变化和进食量;采用自动血糖仪和血糖试纸检测空腹血糖水平;18和22周时进行葡萄糖耐量试验(Glucose tolerance test,GTT)和胰岛素耐量试验(Insulin tolerance test,ITT);计算肝重/体重指数;全自动生化分析仪检测血脂水平。结果 STZ组子代出生体重和后期体重及每日进食量均始终显著低于CON组(P<0.05或P<0.01);第18周,STZ组与CON组子代葡萄糖耐量及胰岛素耐量差异均无统计学意义(P>0.05);第22周时,STZ组子代葡萄糖耐量在第15、30、60 min显著高于CON组(P<0.05),胰岛素耐量在各检测时间点均显著高于CON组(P<0.05);STZ组与CON组子代肝重/体重指数差异无统计学意义(P>0.05);STZ组子代血清中甘油三酯含量明显低于CON组(P<0.05)。结论父代高血糖对子代的出生体重和生长趋势有显著影响,且能显著改善子代的胰岛素耐量。     

马蹄香对小鼠的急性毒性及对大鼠的亚急性毒性观察

目的观察马蹄香(Valeviana jatamansi Jones)对小鼠的急性毒性及对大鼠的亚急性毒性,以评价其安全性。方法给小鼠灌服5 000、7 500、10 000 mg/kg的马蹄香,对照组灌胃1%羧甲基纤维素钠(CMC),观察小鼠的中毒症状,记录小鼠的死亡数,采用Red-Munchen法计算半数致死量(LD50),并检查小鼠组织和脏器的病理变化;对大鼠分别灌服4 000、1 000和200 mg/kg的马蹄香,连续给药14 d,对照组灌胃CMC水溶液,给药后观察14 d,检测大鼠体重、脏器系数、血常规指标、血生化指标及组织病理变化情况。结果急性毒性试验结果显示,灌胃马蹄香后,小鼠短时间内出现活动减少,而后趋于正常,病理学检测未发现小鼠组织或脏器有明显异常改变,LD50>10 000 mg/kg;亚急性毒性试验结果显示,马蹄香各剂量组大鼠的增重、脏器系数、血常规指标、血生化指标及组织病理变化与对照组比较,差异均无统计学意义(P>0.05)。结论马蹄香具有较好的安全性。     

Combined extracts of <Emphasis Type="Italic">Garcinia mangostana</Emphasis> fruit rind and <Emphasis Type="Italic">Cinnamomum tamala</Emphasis> leaf supplementation enhances muscle strength and endurance in resistance trained males

Background

A proprietary composition GMCT contains extracts of two popular Asian herbs viz., Garcinia mangostana (GM) fruit rind and Cinnamomum tamala (CT) leaf. We systematically evaluated physical performance and muscle strength enhancing ability of GMCT in a preclinical mouse model followed by a 42-days double-blind placebo controlled human trial in resistance trained adult males.

Methods

Four groups of Swiss albino mice (20–30 g body weight) (n?=?6) were fed a standard laboratory diet and given Carboxymethylcellulose sodium (CMC), 150 mg/kg GMCT (GMCT-150), 300 mg/kg GMCT (GMCT-300) or 50 mg/kg Oxymetholone (OXY) via oral gavage for 21 days. On day 22, the animals’ physical performance and muscle strength were assessed in a forced swimming test (FST) and forelimb grip strength experiment, respectively.In the human trial, thirty-eight resistance-trained young adults (mean age 26.32?±?4.39 years, body weight 67.79?±?12.84 kg, BMI 22.92?±?3.54 kg/m²) completed the trial. The participants received either GMCT (n?=?19; 800 mg daily) or matched placebo (n?=?19) for 42 days. As primary variables, 1-RM bench press, 1-RM leg press, and leg extension repetitions were measured at baseline and on days 14, 28 and 42 of the intervention. Anthropometric parameters and serum markers such as free testosterone, insulin-like growth factor 1 (IGF-1), insulin and lactate were also measured before and after the intervention.

Results

GMCT-300 mice showed significant improvement in swimming time (GMCT: 395.3?±?81.70 s vs. CMC: 271.6?±?56.86 s; p?=?0.0166), distance (GMCT: 341.22?±?65.88 m vs. CMC: 260.84?±?49.15 m; p?=?0.0461) and grip strength (GMCT: 43.92?±?6.97 N vs. CMC: 35.0?±?6.92 N; p?=?0.0490), compared with the CMC group.At the end of the 42-day human trial, the per protocol analyses reveal that mean changes from baseline 1-RM bench press (GMCT: 23.47?±?10.07 kg vs. PL: 3.42?±?2.06 kg; p?<?0.0001), leg press (GMCT: 29.32?±?16.17 kg vs. PL: 5.21?±?1.72 kg; p?<?0.0001), number of leg extension repetitions (GMCT: 6.58?±?2.57 vs. PL: 2.05?±?1.22; p?<?0.0001) in GMCT group were significantly improved, compared with placebo. Intergroup difference analyses show that the changes from baseline left arm (GMCT: 1.09?±?0.36 cm vs. PL: 0.68?±?0.42 cm; p?=?0.0023), right arm (GMCT: 1.50?±?0.44 cm vs. PL: 1.11?±?0.43 cm; p?=?0.0088) circumference and lean mass (GMCT: 2.29?±?2.09 kg vs. PL: 0.52?±?2.58 kg; p?=?0.0404) in GMCT group were also significantly improved, compared with placebo. In comparison to placebo, GMCT supplementation did not improve free testosterone, IGF-1, insulin or lactate levels. Parameters of clinical biochemistry, hematology, urine and vital signs of the participants were within the normal range.

Conclusion

GMCT supplementation is effective in increasing muscle strength, muscle size and, total lean mass, as well as endurance performance.Trial Registration.Clinical Trial Registry of India (CTRI/2015/01/005374), Registered on Jan 07, 2015; CTRI Website URL - http://ctri.nic.in

     

Intravenous Single-Dose Toxicity of Redaporfin-Based Photodynamic Therapy in Rodents

We assessed the tolerability and safety in rodents of a single intravenous (i.v.) dose of redaporfin, a novel photosensitizer for Photodynamic Therapy (PDT) of cancer. Two approaches were used to evaluate acute toxicity: (i) a dose escalation study in BALB/c mice to evaluate the maximum tolerated dose of redaporfin; and (ii) a safety toxicology study in Wistar rats, of a single dose of redaporfin, with or without illumination, to evaluate possible signs of systemic toxicity. Redaporfin formulation was well tolerated by mice, with no signs of adverse reactions up to 75 mg/kg. In rats, there were no relevant changes, except for a significant, but transient, increase in the blood serum markers for hepatic function and muscle integrity, and also on neutrophil counts, observed after the application of light. The overall results showed that redaporfin-PDT is very well tolerated. No abnormalities were observed, including reactions at the injection site or skin phototoxicity, although the animals were maintained in normal indoor lighting. Redaporfin also showed a high efficacy in the treatment of male BALB/c mice with subcutaneously implanted colon (CT26) tumours. Vascular-PDT with 1.5 mg/kg redaporfin and a light dose of 74 J/cm² led to the complete tumour regression in 83% of the mice.     

Hypoglycemic Effects of Crude Polysaccharide from Purslane

The effects of crude polysaccharide from Purslane (CPP) on body weight (bw), blood glucose, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), triglyceride (TG) and serum insulin levels were studied in diabetes mellitus mice. CPP treatment (200, 400 mg/kg bw) for 28 days resulted in a significant decrease in the concentrations of fasting blood glucose (FBG), TC and TG. Furthermore, CPP significantly increased the concentration of HDL-c, body weight and serum insulin level in the mice. In addition, according to acute toxicity studies and single cell gel electrophoresis analysis, CPP did not produce any physical or behavioral signs of toxicity. More significantly, our data demonstrated CPP exhibited the best effects at the dose of 400 mg/kg bw. The above results suggest that CPP can control blood glucose and modulate the metabolism of glucose and blood lipids in diabetes mellitus mice, so we conclude that CPP should be evaluated as a candidate for future studies on diabetes mellitus.     

腈菌唑毒性研究

利用霍恩氏法测定９９％腈菌原药对大小嫌的急性经口ＬＤ５０值分别为：大鼠雄性１４７０毫克／公斤，雌性１０８０毫克／公斤；小鼠雄性１０８０毫克／公斤，雌性６８１毫克／公斤。经皮ＬＤ５０值雌雌均大于１００００毫克／公斤。     

Relationships between Very Low-Density Lipoproteins–Ceramides, −Diacylglycerols,and –Triacylglycerols in Insulin-Resistant Men

This short report describes the relationships between concentrations of ceramides (CER), diacylglycerols (DAG), triacylglycerols (TAG) in very low-density lipoproteins (VLDL) particles, and hepatic lipid accumulation. VLDL particles were isolated from male subjects (n = 12, mean ± SD, age 42.1 ± 5.4 years, BMI 37.4 ± 4.1 kg/m², ALT 45 ± 21 U/L) and apolipoprotein B100 (apoB100), VLDL-TAG, -CER, and -DAG quantified. The contents of all three lipids were highly correlated with VLDL particle number (r ≥ 0.768, p ≤ 0.003). The molar quantity of VLDL-TAG was 3× that of DAG and 137× that of CER (14,053 ± 5714, 5004 ± 2714, and 105 ± 49 mol/mol apoB100, respectively). Reduced VLDL-CER concentrations were associated with both higher insulin levels (r = −0.645, p = 0.024) and intrahepatic-TAG (r = −0.670, p = 0.017). In fatty liver, the secretion of hepatic TAG, CER, and DAG may be suppressed and contribute to intrahepatic lipotoxicity. The mechanisms by which hepatic-CER and -DAG synthesis and assembly into VLDL is coordinately controlled with TAG will be important in understanding the emerging role of elevated CER contributing to cardiometabolic disease.     

Pharmacokinetics and tissue distribution of vinorelbine delivered in parenteral lipid emulsion

The pharmacokinetics and biodistribution of vinorelbine (VRB) delivered in a parenteral lipid emulsion (VLE) were evaluated, and compared with that of a commercial vinorelbine injectable solution (Navelbine® i.v., VS). After intravenous administration to rats at doses of 2.25, 4.5, and 9 mg/kg, the AUC_{0–24 h} was significantly different (1.15 ± 0.27, 2.65 ± 0.82, and 8.18 ± 1.10 mg/L/h for 2.25, 4.5, and 9 mg/kg, respectively), other pharmacokinetic parameters of VLE, such as the Cmax, CL, and Vss, were also dependent on the dose of VLE. The pharmacokinetics of VLE in rats was dose‐dependent in the dosage range of 2.25–9 mg/kg. VLE exhibited significantly higher VRB concentration than that of VS at the initial time points, it also produced a higher AUC_{0–24 h}, MRT and lower CL in comparison with VS. In beagle dogs, VLE exhibited pharmacokinetic bioequivalence to VS. The tissue distribution in mice of VLE was modified compared to VS, the AUC_{0–48 h} of VLE was grater in the liver, spleen, kidney and small intestine, but a little lower in the heart and lung. Practical applications: To reduce the severe local venous irritation of vinorelbine (VRB) at the aim of improve patient compliance, a parenteral vinorelbine loaded lipid emulsion (VLE) has been developed, and then systematical preclinical evaluations have been done. The pharmacokinetics and tissue distribution study reported here are part of the preclinical evaluation. VLE exhibited non‐linear relationship between dose and AUC_{0–24 h} after single intravenous dose (at doses of 2.25, 4.5, and 9 mg/kg) to rats. Pharmacokinetic bioequivalence between VLE and VS was found after single intravenous infusion administration a dose of 1.33 mg/kg to beagle dogs. Tissue distribution results showed that the AUC_{0–48 h} of VLE was grater in the liver, spleen, kidney, and small intestine, but a little lower in the heart and lung. These results could provide information for the further pharmacodynamics and pharmacology study, and finally for clinical use of VLE.     

Chronic free fatty acid infusion in rats results in insulin resistance but no alteration in insulin-responsive glucose transporter levels in skeletal muscle

To investigate the mechanism by which free fatty acids (FFA) affect glucose uptake, we studied the effect of chronic elevation (24 h) of plasma FFA in rats on whole body glucose disposal and glucose utilization index (GUI) in the basal state and under a euglycemic hyperinsulinemic clamp in relation to the amount of insulin-responsive glucose transporter (IRGT, i.e., GLUTU), protein in different muscles (oxidative and glycolytic) and adipose tissue. Infusion of Intralipid in the basal state led to a∼40% increase in whole body glucose uptake and a∼250% increase in GUI in adipose tissue as compared to control rats. There was no change in the amount of IRGT protein in any of the muscle types whereas in fat depots it was either unchanged or decreased. Under moderate or supraphysiological hyperinsulinemia, increment of whole body glucose disposal was significantly lower in Intralipid perfused rats when compared to controls (∼110 μU/mL: 0.7±0.1 vs. 1.3±0.1 mg/min,P<0.02; ∼1000 μU/mL: 3.0±0.2 vs. 3.9±0.4 mg/min,P<0.02). Under moderate hyperinsulinemia stimulation, GUI was significantly reduced in different muscles and adipose tissue as compared to controls. We conclude that peripheral insulin resistance which occurs after elevation of plasma FFA levels does not seem to be explained by changes in the amount of IRGT protein in either oxidative or glycolytic skeletal muscle. Thus fatty acid infusion appears to be associated with a defect in IRGT translocation to the plasma membrane, fusion with the membrane, or intrinsic activity.