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PubMed1980

Rat liver regeneration in the presence of nonbenzenoid aromatic agents: ferrocenes and cycloheptatrienes.

The extent of liver regeneration in partially hepatectomized rats was increased over a period of 10 days on feeding a basal diet supplemented with 1,1'-diacetylferrocene at 0.15% by weight but the respective differences over the controls were not significant with diets containing ferrocene (0.10 and 0.30%) and acetylferrocene (0.10%) or on sc injection of these agents in peanut oil solution. Tropolone and colchicine supplemented at 750 and 100 PPM, respectively, depressed the regenerative process. The wet and dry liver weight percentages were increased in intact rats fed acetylferrocene (0.15%) or diacetylferrocene (0.060%) but not with ferrocene (0.20%) or with the three injected by the sc route. Hepatic iron deposition was extensive in operated rats fed ferrocene and diacetylferrocene but was far lower in the intact animals on these diets or in the groups injected with the agents.

Animals↗

PubMed1995

Development of a ferrocene-mediated needle-type glucose sensor covered with newly designed biocompatible membrane, 2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate.

To prepare the long-life and stable glucose sensor, we developed the ferrocene-mediated needle-type glucose sensor covered with newly designed biocompatible membrane, 2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate (MPC-co-BMA) membrane. In this membrane, the hydrophilic phosphorylcholine chains were grafted on the hydrophobic polymer surface. 1. The poly(MPC-co-BMA) membrane inhibited platelet activation and protein adhesion on the surface, showing excellent biocompatibility. These results suggested that the hydrophilic phospholipids chains might have the potential for suppressing activation and adsorption of biochemical molecules. 2. The ferrocene-mediated needle-type glucose sensor covered with poly(MPC-co-BMA) membrane achieved excellent results in vitro. Subcutaneous tissue glucose concentrations were measured in a wide range from 1.7 to more than 16.7 mmol/l. The correlation between subcutaneous tissue (Y) and blood (X) glucose concentrations was Y = 1.04X + 0.12 (r = 0.98). The subcutaneous tissue glucose concentrations could be monitored precisely for 7 days without any in vivo calibrations, and for 14 days by introducing in vivo calibrations. We therefore conclude that this sensor is stable and reliable, as compared to any other glucose sensors we developed.

Adult↗

PubMed1993

[The inhibiting effect of dimethylaminomethylferrocene on amylase].

The effects of dimethylaminomethylferrocene (DMAMF) on amylose and maltodextrins destruction by gluco-, alpha- and beta-amylases have been studied. The nature of DMAMF effects depends on the action mechanism of amylases and structure of their active sites. The effect observed is interpreted in terms of a hypothesis on a subsite structure of the amylase active centers.

Amylases↗

PubMed1995

Ethane exhalation and vitamin E/ubiquinol status as markers of lipid peroxidation in ferrocene iron-loaded rats.

Organ damage caused by iron overload has been mostly attributed to iron-induced peroxidation of membrane lipids. Using the ferrocene iron-loaded rat model, we studied ethane exhalation as a direct marker of in vivo lipid peroxidation, as well as concentrations of alpha-tocopherol and ubiquinol 9/10 in liver and plasma as indirect markers of this process. The feeding of a diet enriched with 0.5% TMH-ferrocene up to 31 weeks resulted in a large increase in liver iron concentration to about 25 mg/g wet weight (w wt). At lower, predominantly hepatocellular liver siderosis, the breath ethane exhalation was dependent on dietary vitamin E (VitE) supplements (onset of ethane exhalation at liver-Fe > 2 mg/g w wt on vitE-restricted diet; > 5 mg Fe per gram on VitE-replete diet). At severe liver siderosis, breath ethane exhalation reached a maximum of approximately 8 nmol/kg/hr independent of VitE supplementation. Plasma as well as hepatic alpha-tocopherol decreased with progressive iron loading. In addition, a significant depletion in hepatic ubiquinol 9 and 10 was noted.

Animals↗

PubMedDate not supplied

[Protective action of 5-hydroxy-6-methyluracil and ferrocenes in nitrite-ion poisoning].

It is shown that ferrocenes and 5-oxy-6-methyluracil efficiently inhibit methemoglobin-formation in experiments in vitro and in vivo. Preliminary administration of ferrocene or 5-oxy-6-methyluracil to laboratory animals essentially increases life time in case of sodium nitrite intoxication. Ferrocene protection from sodium nitrite intoxication normalizes the level of methemoglobin and lipoperoxidation in erythrocytes as well as activity of superoxide dismutase of erythrocytes. Activity of catalase, glutathione reductase and dehydrogenases of the pentosephosphate way were not normalized during ferrocene protection from sodium nitrite intoxication. In case of ferrocene protection the catalase activity during sodium nitrite intoxication remains lowered, while activity of glutathione reductase and dehydrogenases of the pentosephosphate pathway grows sharply.

Animals↗

PubMed1998

Accumulation of iron by primary rat hepatocytes in long-term culture: changes in nuclear shape mediated by non-transferrin-bound forms of iron.

We have previously shown that hepatocytes in long-term dimethylsulfoxide (DMSO) culture, fed a chemically defined medium, are highly differentiated and an excellent in vitro model of adult liver. Hepatocytes in long-term DMSO culture can be iron loaded by exposure to non-transferrin-bound iron (NTBI) in the form of ferrous sulfate (FeSO4), ferric nitrilotriacetate, or trimethylhexanoyl (TMH)-ferrocene. Holotransferrin, at equivalent times and concentrations, was unable to load hepatocytes. Of the iron compounds tested, TMH-ferrocene most accurately simulated the morphological features of iron-loaded hepatocytes in vivo. When exposed to 25 micromol/L TMH-ferrocene, hepatocytes loaded increasing amounts of iron for 2 months before the cells died. When exposed to lower concentrations of TMH-ferrocene (as low as 2.5 micromol/L), hepatocytes continuously loaded iron and remained viable for more than 2 months. The cellular deposition of iron was different in hepatocytes exposed to TMH-ferrocene compared with those exposed to FeSO4; exposure to TMH-ferrocene resulted in the presence of more ferritin cores within lysosomes than were seen with FeSO4. When the concentration of TMH-ferrocene was increased, a greater number of ferritin cores were observed within the lysosome, and total cellular ferritin, as assessed by Western blot, increased. The formation of hemosiderin was also observed. Furthermore, nuclear shape was distorted in iron-loaded hepatocytes. The extent of deviation from circularity in the nucleus correlated with increasing concentrations of TMH-ferrocene and was greater in hepatocytes exposed to FeSO4 than an equivalent concentration of TMH-ferrocene. The deviation from circularity was smallest in hepatocytes that contained well formed ferritin cores and increased in hepatocytes that contained greater amounts of hemosiderin. Furthermore, in hepatocytes treated with FeSO4, a large amount of cell-associated iron was detected but without a significant increase in the total amount of ferritin. The deviation from circularity was the largest in FeSO4-treated hepatocytes, indicating that iron not properly incorporated into ferritin caused more cellular damage. We conclude that iron-loaded hepatocytes in long-term DMSO culture represent a flexible system for studying the effects of chronic iron loading on hepatocytes.

Animals↗

PubMed1999

Metabolism of 3,5,5-trimethylhexanoyl-ferrocene by rat liver: release of iron from 3,5,5-trimethylhexanoyl-ferrocene by a microsomal, phenobarbital-inducible cytochrome P-450.

3,5,5-Trimethylhexanoyl (TMH)-ferrocene has been used to produce iron loading in whole animals and in cultured hepatocytes. Iron loading produced by TMH-ferrocene is highly efficient and, of the compounds used to produce iron loading in experimental systems, most closely mimics the loading patterns observed in the human disease hemochromatosis. Previous work with TMH-ferrocene has shown that TMH-ferrocene is degraded in vivo because the iron is released from the ferrocene nucleus. Because TMH-ferrocene is highly lipophilic and stable chemically, we hypothesize that this molecule indeed could be degraded enzymatically. To measure the breakdown of TMH-ferrocene, iron release from the molecule was analyzed using a Ferrochem II analyzer, which uses constant potential coulometry to measure the amount of ionic iron within a biological sample. In this study, we show that TMH-ferrocene is degraded by a microsomal enzyme that requires NADPH and molecular oxygen. The TMH-ferrocenase activity is heat labile, requires a physiologic temperature, is induced by phenobarbital, and is inhibited by carbon monoxide and piperonyl butoxide but not by dicoumarol. The enzyme follows Michaelis-Menten kinetics and has a Km of 58.5 microM and a Vmax of 57.5 nmol Fe released/mg protein/min. We conclude that TMH-ferrocene is degraded by a phenobarbital-inducible cytochrome P-450.

Anaerobiosis↗