Formation of lipoperoxide in isolated sciatic nerve by chinoform-ferric chelate

Summary Effects of chinoform and chinoform-ferric chelate on formation of lipoperoxide in isolated sciatic nerve were investigated. Free chinoform did not increase the lipoperoxide level, while chinoform-ferric chelate significantly increased it. Assuming that the lipoperoxide formed denatures the associated protein in the nerve, the effect of chinoform-ferric chelate could explain, at least partly, the demyelination of nerve tissues caused by massive doses of chinoform.     

Degeneration of retinal neuroblasts by chinoform-ferric chelate

The possible mechanism of neuropathic effect of chinoform was investigated using cultured retinal neuroblasts from chick embryos. Retinal neuroblasts completely degenerated by chinoform-ferric chelate within a day. This change, however,, was not observed with free chinoform or ferric ion alpha-Tocopherol had a potent protective effect on the toxicity of the chelate. From these results, it was concluded that the lipid peroxidation due to ferric ion chelated with chinoform incorporated into the membrane of nerve tissues is the most important step in induction of the neuropathy.     

Degeneration of retinal neuroblasts by chinoform-ferric chelate

Summary The possible mechanism of neuropathic effect of chinoform was investigated using cultured retinal neuroblasts from chick embryos. Retinal neuroblasts completely degenerated by chinoform-ferric chelate within a day. This change, however, was not observed with free chinoform or ferric ion.a-Tocopherol had a potent protective effect on the toxicity of the chelate. From these results, it was concluded that the lipid peroxidation due to ferric ion chelated with chinoform incorporated into the membrane of nerve tissues is the most important step in induction of the neuropathy.This work was supported in part by a grant from the Ministry of Health and Welfare of Japan.Correspondence should be addressed to K. Yagi, Institute of Biochemistry, Faculty of Medicine, University of Nagoya, Nagoya 466, Japan.     

Lipid peroxidation caused by chinoform-ferric chelate in cultured neural retinal cells

Incorporation of chinoform-ferric chelate was demonstrable in cultured neural retinal cells of chick embryos after 1 h of incubation, and the lipid peroxide level in the cells was increased strikingly 1 h thereafter. On the other hand, free ferric ions were scarcely incorporated into the cells, and a significant increase in the lipid peroxide level in the cells was not observed. These data indicate that chinoform is carrier of iron for its passage through cell membranes and that the incorporated iron induces lipid peroxidation which in turn leads to neural cell degeneration.     

Lipid peroxidation caused by chinoform-ferric chelate in cultured neural retinal cells

Summary Incorporation of chinoform-ferric chelate was demonstrable in cultured neural retinal cells of chick embryos after 1 h of incubation, and the lipid peroxide level in the cells was increased strikingly 1 h thereafter. On the other hand, free ferric ions were scarcely incorporated into the cells, and a significant increase in the lipid peroxide level in the cells was not observed. These data indicate that chinoform is carrier of iron for its passage through cell membranes and that the incorporated iron induces lipid peroxidation which in turn leads to neural cell degeneration.This work was supported in part by a grant from the Ministry of Health and Welfare of Japan     

Effect of albumin on uncoupling of oxidative phosphorylation by chinoform in rat liver mitochondria.

Addition of serum albumin diminished the uncoupling effect of chinoform on oxidative phosphorylation in rat liver mitochondria. Upon increasing the concentration of magnesium ions in the medium, the action of serum albumin was diminished. These results indicate that serum albumin combines with chinoform in competition with magnesium ions.     

Formation of lipoperoxide in the retina of rabbit exposed to high concentration of oxygen.

When rabbit was exposed to high concentrations of oxygen, lipoperoxide in the retina was increased at 12 h of the exposure, after which period amplitude of electro-retinogram decreased. The degeneration was observed in the visual cell layer of the retina of the exposed animal.The exposure increased lipoperoxide in isolated retina. These data show the intervention of lipoperoxide in retinal degeneration by exposure to high concentration of oxygen.     

Formation of lipoperoxide in the retina of rabbit exposed to high concentration of oxygen

Summary When rabbit was exposed to high concentration of oxygen, lipoperoxide in the retina was increased at 12 h of the exposure, after which period amplitude of electro-retinogram decreased. The degeneration was observed in the visual cell layer of the retina of the exposed animal. The exposure increased lipoperoxide in isolated retina. These data show the intervention of lipoperoxide in retinal degeneration induced by exposure to high concentration of oxygen.     

Lipoperoxide formation in the retina in ocular siderosis

Summary Insertion of iron nail into the vitreous cavity provoked the formation of lipoperoxide in the retina. In accord with the increase in lipoperoxide in the retina, ERG began to decrease. In vitro experiment using isolated retina, lipoperoxide was found to be increased in the presence of ferric or ferrous ions, while it was inhibited by adding antioxidants or ethylenediamine tetraacetate. From these results, direct cause of retinal degeneration in siderosis could be ascribed to the formation of lipoperoxide by iron-ions liberated from the piece of iron, resulting into the degeneration of the visual cell layers of the retina.     

Cadmium-induced changes in renal hemodynamics in the domestic fowl

Low i.v. doses of cadmium chloride (15 micrograms Cd) given to pullets resulted in a significant reduction in urine flow (UF), glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). However, in hens treated with the heavy metal chelate FeNa EDTA prior to cadmium treatment no oliguria or reduction in GFR or ERPF was observed. It is suggested that the renal changes following the i.v. administration of cadmium to diuretic hens and alleviated in hens primed with the heavy metal chelate may result from changes in glomerular hemodynamics.     

Cadmium-induced changes in renal hemodynamics in the domestic fowl

Summary Low i.v. doses of cadmium chloride (15 g Cd) given to pullets resulted in a significant reduction in urine flow (UF), glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). However, in hens treated with the heavy metal chelate FeNa EDTA prior to cadmium treatment no oliguria or reduction in GFR or ERPF was observed.It is suggested that the renal changes following the i. v. administration of cadmium to diuretic hens and alleviated in hens primed with the heavy metal chelate may result from changes in glomerular hemodynamics.     

Chelate treatment in acute cadmium poisoning

Summary Treatment of cadmium-poisoned rats with mixed ligand chelates does not decrease the lethality of cadmium more than treatment with one chelate alone.     

Inhibition of paraquat phytotoxicity by a novel copper chelate with superoxide dismutating activity.

A chelate with superoxide dismutase activity, D-penicillamine copper complex, was shown to inhibit paraquat toxicity in flax cotyledons (Linum usitatissimum var. Reina). Paraquat-stimulated chlorophyll loss and ethane production were markedly reduced by this complex. The role of superoxide in the action of paraquat is briefly discussed.     

Cadmium-induced changes in avian renal morphology

Summary The effects of i.m. administered cadmium on growth rate and nephromorphology were studied in young pullets. The growth rate of pullets treated with 0.6 mg Cd²⁺/kg at 48-h intervals was severely retarded, reaching only 50% of normal growth by 21 days. Such a decrease in growth rate was prevented when cadmium was given with either ferric or magnesium EDTA chelate. Electron micrographs of kidney tissue from cadmium intoxicated birds revealed massive intracellular disorganisation of proximal tubular cells, showing increased vacuolation and dilated endoplasmic reticulum. Mitochondria were few and swollen with reduced cristae. Some disorganisation was noted in the group treated with MgEDTA in conjunction with cadmium, with normal morphology observed in the group treated FeEDTA plus cadmium.In general, glomerular morphology of intoxicated pullets appeared normal, except that a 25% increase in thickness of the glomerular basement membrane was evident. No such membrane thickening was observed in any of the chelate treated groups.These findings indicate that both chelates can provide certain levels of protection, in terms of growth rate and morphology, from cadmium intoxication. The possible mechanisms by which chelates offer protection have been discussed, but many questions remain unanswered.     

Schwefel als Ligandatom in Chelatkomplexen

Summary The hitherto unknown compounds 5-(2-pyridyl)thiazole, 2-(2-thienyl)pyridine and methyl--picolyl sulphide have been synthesized. The structure of all three substances allows the formation of a chelate ring with N and S as ligand atoms. 5-(2-Pyridyl)thiazole yields with Fe²⁺ at a pH of 2.5 a significant change in absorption, which is attributed to chelate formation.     

Inhibition of paraquat phytotoxicity by a novel copper chelate with superoxide dismutating activity

Summary A chelate with superoxide dismutase activity, D-penicillamine copper complex, was shown to inhibit paraquat toxicity in flax cotyledons (Linum usitatissimum var. Reina). Paraquat-stimulated chlorophyll loss and ethane production were markedly reduced by this complex. The role of superoxide in the action of paraquat is briefly discussed.This work was supported by grants from the German Academic Exchange Service to R.J. Youngman and by I.C.I. Ltd, Plant Protection Division.     

Vergleichende Untersuchungen über die Toxizität der Ca- und Zn(II)-Chelate der Diäthylentriaminpentaessigsäure

Summary The lethal effect of daily intraperitoneal administrations of Ca-DTPA and Zn(II)-DTPA was studied in mice. Due to recovery processes, single chelate doses are non-additive and the cumulative LD₅₀ increases with decreasing daily dosage. At a given number of administrations, Zn(II)-DTPA is 2.5 times less toxic than Ca-DTPA. However, if the daily dosage is kept constant and the number of administrations variable, Zn(II)-DTPA is 30 times less toxic.     

Synkinesis in hemifacial spasm: results of recording intracranially from the facial nerve

Summary We show evidence that the motonucleus of the facial nerve is involved in producing the synkinesis in patients with hemifacial spasm. These results were obtained by recording from the intracranial portion of the facial nerve and from the orbicularis oculi muscle in patients operated upon for hemifacial spasm during electrical stimulation of the mandibular branch of the facial nerve. Also, the electromyographic response from the same muscle was recorded when the facial nerve was electrically stimulated at a location near the brainstem. The results show that it is unlikely that the symptoms of patients with hemifacial spasm can be explained on the basis of ephaptic transmission at the site of lesion of the facial nerve.     

Synkinesis in hemifacial spasm: results of recording intracranially from the facial nerve

We show evidence that the motonucleus of the facial nerve is involved in producing the synkinesis in patients with hemifacial spasm. These results were obtained by recording from the intracranial portion of the facial nerve and from the orbicularis oculi muscle in patients operated upon for hemifacial spasm during electrical stimulation of the mandibular branch of the facial nerve. Also, the electromyographic response from the same muscle was recorded when the facial nerve was electrically stimulated at a location near the brainstem. The results show that it is unlikely that the symptoms of patients with hemifacial spasm can be explained on the basis of ephaptic transmission at the site of lesion of the facial nerve.     

Peptidergic innervation of the temporomandibular disk in the rat

Summary The peptidergic innervation of the temporomandibular disk was investigated in the postnatal young rat by using an indirect immunofluorescence method. Calcitonin gene-related peptide-containing nerve fibers were located around the blood vessels and terminated as free nerve endings in the disk. These nerve fibers may be of a sensory nature.