Modification of adriamycin toxicity in rats fed a high fat diet

Rats fed a diet containing a high percentage of butter, cholesterol, cholic acid and propyl thiouracil (HFD) showed weight loss and developed hyperlipidemia, marked fatty in filtration of the liver, moderate elevation of SGPT, degenerative changes of the heart muscle, bradycardia, alterations of the QRS complex in the electrocardiogram, and initial hemoconcentration followed by moderate anemia. Treatment with adriamycin (18×1 mg/kg i.p.) resulted in significant augmentation of the cardiotoxic effects of this drug demonstrated by electrocardiographic measurements and myocardial histopathology. Adriamycin-induced atrophy of the lymphatic tissue was seen only in rats fed HFD and not in animals receiving ground chow. Adriamycin levels in the heart after single i.p. injection were higher in rats receiving HFD. This effect was present already after 10 days on HFD. At this time histopathological liver changes were present and SGPT was elevated. It is concluded that the increase in adriamycin toxicity is, at least in part, due to diminished excretion by the liver. These experimental findings are in accordance with clinical observations which have identified liver disease as one of the important risk factors for the development of adriamycin cardiomyopathy.     

Effect of adriamycin on electron transport in rat heart, liver, and tumor mitochondria

The effect of Adriamycin on mitochondria of the rat heart, liver, and Ehrlich ascites tumor mitochondria has been evaluated. The results may be summarized as follows: Adriamycin reduces both ADP- and FCCP-stimulated respiration, inhibits oxidative phosphorylation, decreases mitochondrial ATP-ase activity, and affects the redox state of respiratory carriers. These alterations are common to all types of mitochondria tested with almost similar patterns. However, the severe cardiotoxicity of the drug cannot be ascribed only to an effect on mitochondrial energy-yielding processes. The addition of hexokinase to phosphorylating heart mitochondria does not increase the sensitivity of succinate oxidation to Adriamycin. Experiments to determine the site of action were not able to detect a specific point of attack. It is conceivable, therefore, that the modifications induced by Adriamycin on the functional parameters of mitochondria may be ascribed to alterations of the physical state of some components of the inner mitochondrial membrane, e.g., lipids, which regulate the kinetic properties of the membrane-associated enzymes.     

M-2000, as a new anti-inflammatory molecule in treatment of experimental nephrosis

The therapeutic effect of M-2000 (C6H10O7) molecule was tested in Adriamycin-induced nephropathy. To induce experimental nephrosis, Adriamycin was given once by a single intravenous injection (7.5 mg/kg) through the tail vein. Six days after injection of Adriamycin, therapeutic protocol was developed by intraperitoneally (i.p) administration of 30 mg/kg M-2000 solution. Total of i.p. injections were 14, in which five injections were made every day and nine injections were carried out at regular 48-h intervals. Therapeutic protocol was terminated on day 28 and animals were killed on day 43. The treated patient rats showed a significant reduction in proteinuria, BUN, serum creatinine and serum cholesterol, as well as, administration of M-2000 could significantly diminish the serum level of interleukin-6 (IL-6) in treated animals compared to non-treated controls. Moreover, treatment with M-2000 significantly reduced number of glomerular leukocytes, Hypercellularity and hydropic change in capillary network within the renal cortex and decreased tubular casts. These data suggest that M-2000 therapy can ameliorate proteinuria, and suppress the progression of glomerular lesions in experimental model of nephrosis.     

Ultrastructural features of Adriamycin-induced skeletal and cardiac muscle toxicity.

In this study, the authors examined the effect of the anti-tumor agent Adriamycin, a known cardiotoxin, on mouse heart, diaphragm, and gastrocnemius muscle. Using an established model of Adriamycin cardiac toxicity, they found that 4 days after the intraperitoneal injection of 20 mg/kg of Adriamycin, characteristic heart lesions, including vacuolation of the sarcoplasmic reticulum, interstitial edema, and mitochondrial degeneration, were demonstrated in all treated animals. Furthermore, similar, but much more severe, myocyte damage was demonstrated in the diaphragm; muscle toxicity followed a decreasing gradient of injury from the peritoneal to the thoracic surface of the tissue. On the other hand, treatment with Adriamycin resulted in an increase in the size and number of lipid droplets in the red fibers of the gastrocnemius muscle without any other ultrastructural evidence of drug-induced damage to myocytes. An examination of the pharmacokinetics and metabolism of Adriamycin after intraperitoneal treatment revealed that relative drug levels in muscle (diaphragm much greater than heart much greater than gastrocnemius) paralleled the degree of ultrastructural damage observed. This study indicates that treatment with Adriamycin can produce significant injury to non-cardiac muscle in a fashion that strongly resembles the characteristic pattern of Adriamycin-related damage to the heart, and that the degree of myocyte damage is apparently dependent upon the Adriamycin concentration in the tissue.     

Lipid lowering: an important factor in preventing adriamycin-induced heart failure.

The contribution of lipid lowering in protection against adriamycin cardiomyopathy achieved by probucol, an antioxidant and a lipid-lowering drug, was assessed by comparing its beneficial effects with that of lovastatin, another lipid-lowering drug with no known antioxidant properties. Adriamycin (cumulative dose, 15 mg/kg body weight) was given to rats in 6 equal injections (intraperitoneally) over a period of 2 weeks. Probucol (cumulative dose, 120 mg/kg body weight) or lovastatin (cumulative dose, 48 mg/kg body weight) was given in 12 equal injections (intraperitoneally) before and concurrent with adriamycin. After 3 weeks of post-treatment with adriamycin, congestive heart failure, ascites, congested liver, and depressed cardiac function were seen. Adriamycin treatment decreased glutathione peroxidase activity and increased lipid peroxidation. Adriamycin increased plasma triglycerides, total cholesterol, and high- and low-density lipoproteins. Myocardial triglycerides and total cholesterol were also increased. Probucol completely prevented the development of congestive heart failure and normalized myocardial and plasma triglycerides and total cholesterol, and significantly decreased plasma high- and low-density lipoproteins. Lovastatin significantly attenuated but did not completely prevent cardiomyopathic changes due to adriamycin. Lovastatin decreased plasma total cholesterol and low-density lipoproteins as well as myocardial triglycerides and total cholesterol. Plasma triglycerides and high-density lipoproteins were still high in the adriamycin plus lovastatin group. Probucol improved glutathione peroxidase activity and reduced lipid peroxidation whereas lovastatin had no effect on these adriamycin-induced changes. These data suggest that adriamycin cardiomyopathy is associated with an antioxidant deficit as well as increased myocardial and plasma lipids. Complete protection by probucol against adriamycin-induced congestive heart failure may be due to the unique combination of its antioxidant and lipid-lowering properties.     

氯沙坦对大鼠慢性心力衰竭的干预作用

目的 通过氯沙坦对慢性心力衰竭(慢性心衰)干预,研究慢性心衰时心肌细胞凋亡变化的原因及其机制,为慢性心衰的治疗提供理论依据。 方法 采用阿霉素制作慢性心衰大鼠模型,以氯沙坦为干预剂,采用透射电镜、免疫组织化学、RT-PCR及原位缺口末端标记法(TUNEL)对心肌细胞凋亡的形态和凋亡蛋白Bax、Bcl-2及通路蛋白细胞外信号调节激酶（ERK1）、氨基末端激酶（JNK1）和促分裂原活化蛋白激酶（P38MAPK）的mRNA表达变化进行研究。 结果 氯沙坦治疗后,与心衰组动物相比,心肌细胞的超微结构明显好转;凋亡指数明显降低（P <0.01）;Bcl-2的含量明显升高而Bax的含量显著下降（Bcl-2 χ² =6.81、P =0.0074;Bax χ² =66149、P =0.0078,均P <0.01）;ERK1mRNA表达明显增加而JNK1mRNA表达则显著下降（ｑ =15.3514,P <0.01;ｑ =22.0156,P <0.01）。 结论 氯沙坦对慢性心衰的干预作用与ERK1和JNK1途径密切相关,而p38MAPK途径与此过程相关性不大。     

含有篦麻毒素和阿霉素的双弹头免疫毒素的构建及其杀伤活性

本文用化学偶联方法,将篦麻毒素(RiCin)及阿霉素(Adriamycin,Adr)同时偶联到抗人膀胱癌单克隆抗体分子上,构建了第一个具有“双单头”的抗肿瘤导向药物。经间接免疫荧光检测以及放射竞争结合试验证明,这个免疫毒素保持了原抗体活性的70%。体外杀伤试验的结果表明,这个双单头免疫毒素在0.1M半乳糖存在的条件下,对膀胱癌细胞BIU-87的体外杀伤作用比单抗-阿霉索强30000倍;比单抗-篦麻毒素强10倍。对无关的人直肠癌LoVo细胞无明显的杀伤作用。     

新型控释化疗系统的基础研究

研究一种新型的控释化疗系统聚-二聚酸一葵二酸一阿霉索(P(DA—SA)-阿霉索(在脑组织内的相容性、体内外释药特性及体外抑瘤特性。将空载体P(DA—SA)分别植入实验动物脑内，观察局部反应；用紫外线光谱测定P(DA—SA)-阿霉素在磷酸盐缓冲液及兔脑内的控释特性；流式细胞仪检测P(DA—SA)-阿霉索诱发的胶质瘤细胞株的凋亡。P(DA—SA)在兔脑内引起的反应较轻，与明胶海绵相比无明显差异。P(DA—SA)-阿霉素在体内外释药速率稳定，控释时间达3周。控释剂组的胶质瘤细胞凋亡率达69．9％，与对照组有明显差异。P(DA—SA)具有良好的组织相容性，P(DA—SA)-阿霉索控释剂在体内外的控释效果理想，杀伤效应明显，该控释化疗系统有很好的临床应用价值。     

Modulation of adriamycin uptake by lonidamine in Ehrlich ascites tumor cells

The effect of Lonidamine, 1-(2,4 dichlorobenzyl)-1-H-indazol-3-carboxylic acid, on the uptake of Adriamycin by Ehrlich ascites tumor cells has been investigated. The uptake of Adriamycin is greatly stimulated by Lonidamine and the increase depends on the energy sources of the cell. In the presence of glucose the intracellular drug content is remarkably lower than that in its absence. This difference lies in the mechanism by which Lonidamine enhances the uptake of Adriamycin. The Adriamycin efflux is via an active transport process and, in the presence of glucose, both aerobic glycolysis and oxidative phosphorylation contribute to ATP synthesis. Although Lonidamine inhibits both these pathways, there is still sufficient ATP to extrude a certain amount of Adriamycin. The elevated intracellular concentration of Adriamycin depends not only on the Lonidamine-inhibited outward transport but also on higher membrane permeability which allows a low concentration of Adriamycin (18 microM) to interfere also with the oxidative metabolism of Ehrlich ascites tumor cells.     

Selenium improves cardiac function by attenuating the activation of NF-kappaB due to ischemia-reperfusion injury

Although selenium, an essential trace element and a component of glutathione peroxidase, is known to protect the heart from ischemia-reperfusion (I/R)-induced injury, the mechanisms of this protection are not fully understood. For this purpose, isolated rat hearts were subjected to 30 min of global ischemia followed by 30 min of reperfusion; sodium selenite (25-1,000 nM) was added in the perfusion medium 10 min prior to ischemia, as well as during reperfusion. Selenium caused a dose-dependent improvement in cardiac performance and attenuated the decrease in the ratio of reduced glutathione to oxidized glutathione, as well as the increased level of malondialdehyde in I/R heart. Elevated ratios of nuclear factor-kappaB (NF-kappaB) in particulate and cytosolic fraction and of phosphorylated NF-kappaB and total NF-kappaB in I/R hearts were reduced by selenium. Cardiac dysfunction in hearts perfused with xanthine plus xanthine oxidase mixture, as well as hydrogen peroxide, or subjected to Ca2+ paradox was also attenuated by selenium. These data suggest that selenium protects the heart against I/R injury due to its action on the redox state and deactivation of NF-kappaB in I/R hearts.     

Modulation of biological phenotypes for tumor growth and metastasis by target-specific biological inhibitors in gastric cancer.

For tumor progression, a cascade of linked sequential biological events is essential. We tried to test whether biological therapy can modulate specific biological phenotypes and increase the anti-tumor effect when combined with chemotherapy. Five human gastric cancer cell lines (YCC-1, YCC-2, YCC-3, YCC-7, AGS) were used in these studies. Pentosan polysulfate (PPS) as a heparin-binding growth factor inhibitor, Tranexamic acid as a plasmin inhibitor, Lovastatin as an adhesion inhibitor and Adriamycin as a chemotherapeutic agent were selected. The effects of each drug on colony formation and tumor cell proliferation were evaluated by soft agar assay and cell proliferation assay, respectively to test direct anti-tumor effect. The expression of uPA, PAI-1 was determined by ELISA, while MMPs activity was evaluated by zymography. PPS suppressed the colony-forming activity as much as Adriamycin did, but it showed only cytostatic effects in cell proliferation assay. Migration capacity using Boyden chamber assay was more closely correlated with adhesive capacity than uPA or MMP-2 expression. The motility inhibitory effect of Tranexamic acid was observed in the YCC-7 cell line, which expressed all the required biological phenotypes for migration. In AGS, with high cell motility and adhesiveness, the adhesion was inhibited by Lovastatin and most of the inhibitory effect was recovered by Mevalonate. When PPS was combined with Adriamycin on the Adriamycin-resistant, midkine (MK) gene expressing YCC-7 cell line, the growth inhibition rate increased up to 84%, while that for a single treatment of PPS or Adriamycin was 40% and 22%, respectively (p=0.001). When we combined Tranexamic acid and Adriamycin, we observed the synergistic effect in YCC-3 and YCC-7, while no combined effect was found in YCC-1. The combination of Lovastatin and Adriamycin did not show any combined effects in any of the cell lines. In conclusion, a synergistic anti-proliferative effect (chemo-sensitization) with combined chemo-biotherapy was found in cancer cells with specific biological target, MK. The anti-motility effect was the greatest when the gastric cancer cells expressed all the specific biological phenotypes.     

Selenium and the immune response: 1. Modulation of alloreactive human lymphocyte functions in vitro

A role for the dietary trace mineral element selenium in the reduction of cancer incidence has been documented in numerous epidemiological and experimental studies. The precise mechanism of this antitumor effect is not well understood, but published data suggest that both inhibition of tumor cell growth and enhancement of host immunity are likely to be involved. In this study we report that selenium at physiologic concentrations can inhibit human lymphocyte proliferation in response to irradiated tumor cells in mixed lymphocyte/tumor cell cultures (MLTC). In addition, we demonstrate that the various lymphocyte functional activities generated in these cultures exhibit different levels of sensitivity to the effects of selenium. The generation of suppressor-cell activity in MLTC was strongly inhibited by the presence of physiologic levels of selenium, while the development of cytotoxic T-lymphocyte activity in identical cultures was not affected by selenium. Production of interleukin-2 in these cultures showed an intermediate sensitivity to the effects of selenium. Thus, selenium appears to be capable of selectively regulating the generation of functional lymphocyte subsets in vitro. Such selective regulation could explain the published effects of selenium on immunity and would be consistent with a role for immunity in the observed reduction of cancer incidence associated with elevated selenium intake.     

Cis DDP in combination with selenium and sulfur. Subcellular effect in kidney cells. Electron microprobe study

Cis DDP is an anticancer agent used in the treatment of diverse cancers, but its use has been limited by its nephrotoxic effect. We sought to modify this major toxic side effect by the addition of S2O3-- (sodium thiosulfate) or SeO2 (selenium dioxide) or both. In the present study, only ultrastructural and X-ray microanalysis data are reported. No kidney lesions were observed after the administration of SeO2 and Cis DDP in contrast to Cis DDP with S2O3-- or with S2O3-- plus selenium. An organelle of the kidney cell, the lysosome, has a particular role in the concentration of mineral elements in this cell. Platinum was observed in the lysosome along with sulfur, after the administration of Cis DDP and S2O3. Platinum, selenium and sulfur were observed after administration of SeO2, S2O3 and Cis DDP. No mineral deposits were observed after administration of SeO2 and Cis DDP. The role of sulfur seems to be very different from that of selenium. We hypothesize that sulfur favors the intralysosomal concentration of platinum or that selenium associates with platinum. The fact that selenium is not reabsorbed by the kidney cell seems to favor the hypothesis of urinary elimination of platinum. The present work confirms our previous study concerning the role of SeO2 in combination with Cis DDP.     

Effects of calcium channel blocking and atrial stimulation on QT time during hyper- and normocalcemia in man

Summary We investigated how calcium channel blocking agents modify the known decrease of QT time with increasing heart rate and calcium level. Furthermore, we examined how the influence of calcium channel blocking agents is modulated by atrial stimulation. To answer these questions, we measured the QT time both at a spontaneous heart rate and during atrial stimulation with 90 and 110 beats/min before and after intravenous administration of 5 mg verapamil in 23 patients with primary hyperparathyroidism, pre- and postoperatively. Atrial stimulation increased the frequency-related standard values of QT time. The spontaneous heart rate (HR) was influenced by neither the calcium level nor verapamil. The statistically significant correlations QT vs. HR and QT vs. Ca were reduced by verapamil, which indicated its influence. However, this effect did not achieve statistical significance.Abbreviations HR heart rate - MV mean values - SD standard deviation - r correlations - P statistical significance - QT QT time (measured in ms) - QTc frequency-adjusted QT time (Bazett) - NS not significant     

Selenium and vitamin E in relation to risk factors for coronary heart disease.

Fasting blood samples taken from 116 apparently healthy men aged 30-50 years were assayed for selenium, glutathione peroxidase activity, vitamin E, cadmium, lead, glucose, lipids, and albumin. Blood pressure was measured in each subject, and details of height, weight, smoking habits, and alcohol consumption were recorded. Multivariate analysis of the data showed that the decrease in blood and serum concentrations of selenium and the increase in whole blood cadmium concentrations in the cigarette smokers was independent of alcohol consumption. There was no correlation between blood selenium concentrations or glutathione peroxidase activities and the risk factors for cardiovascular disease. Neither alcohol consumption nor smoking had an effect on the vitamin E concentrations. There was a strong association, however, between vitamin E and serum lipid concentrations, although the increase in triglyceride concentrations in the smokers was not matched by a comparable increase in vitamin E. The possible role of selenium in the aetiology of heart disease remains unresolved.     

生长激素释放肽对心衰大鼠心肌组织中IL-6的影响

目的研究心肌组织中白细胞介素-6(interleukin-6,IL-6)的含量变化以及生长激素释放肽(growth hormonereleasing peptide,GHRP)对其影响。方法以阿霉素制备大鼠心衰模型,采用放射免疫学方法检测大鼠心肌组织中IL-6的含量。结果模型组与正常组相比,左室峰压、左室压力最大上升和下降速率(±dp/dtmax)降低,而心肌组织中IL-6含量增高,差异均有统计学意义(P<0.05);治疗组与模型组相比,左室峰压、左室压力最大上升和下降速率(±dp/dtmax)增高,心肌组织中IL-6含量降低,差异均有统计学意义(P<0.05),而与正常组相比差异无统计学意义(P>0.05)。结论IL-6与CHF的发生密切相关,GHRP具有降低心肌组织中IL-6含量和改善CHF大鼠心功能的作用。     

In vitro pharmacological purging of human bone marrow is enhanced by the use of lonidamine

Lonidamine (LND), previously reported as a useful antitumor substance in combination with physical or chemical agents, has been studied for its capacity in increasing pharmacological elimination in vitro of residual tumor cells from human bone marrow. Different drugs were tested in association with LND against mixtures of human bone marrow and a tumor cell line, clonogenic human leukemic blast progenitors, and normal human bone marrow precursors. The results demonstrated that LND increased the efficacy of anthracycline derivatives (Adriamycin, Mitoxantrone) both on the tumor cell line and on the leukemic blast progenitors, while VP-16 or ASTA-Z 7654 was not affected by the same substance. The toxicity on normal stem cells reflected that of each drug and was not modified by the addition of LND. While a consistent dose-dependent CFU-GM reduction was observed immediately after treatment with the different drugs, a complete recovery was reached after 7 and 14 days of long-term marrow cultures. Because of the low toxicity and the efficacy demonstrated in association with certain agents in increasing tumor cell elimination in vitro, LND could play an important role in in vitro purging prior to autologous bone marrow transplantation.