In vitro and in vivo incorporation of 63Ni[II] into lung and liver subcellular fractions of Balb/C mice.

The binding of nickel to proteins in lung and in liver was investigated by analysis of 63Ni[II] incorporation into the nuclear, mitochondrial, microsomal and soluble fractions. Three different procedures were performed: (i) in vitro incorporation, (ii) a time course study of in vivo incorporation where the animals were sacrificed after 30 min, 1, 2 and 4 h after a single i.p. injection of 63NiCl2, (iii) in vivo incorporation after 7 successive i.p. injections of 63NiCl2 every 24 h and the animals were sacrificed 24 h after the last injection. In all cellular fractions (except the nuclear fractions) we could observe several nickel-binding proteins regardless of the type of incorporation performed. Most of these proteins were revealed after in vitro as well as in vivo incorporation, some of them, however, were labelled only after in vitro incorporation, others only after in vivo incorporation. Some proteins can only be revealed after successive injections. In addition, the 63Ni-labelled proteins are not all the same at the beginning of the incorporation (30 min) as after longer periods (1 and 2 h). The lung fractions (especially the mitochondrial fraction) were always more highly labelled than the liver fractions. These biochemical investigations not only confirm that the lung is a target organ for nickel-retention, but also demonstrate that Ni is preferentially bound to its mitochondrial and microsomal fractions. It is shown here that several cellular proteins are implicated in the transport and the metabolism of nickel in the cell.

63Ni[II]-incorporation into lung and liver cytosol of Balb/C mouse. An in vitro and in vivo study.

The kinetic studies of 63Ni[II]-incorporation in whole tissue show that after 6 days lung has the highest affinity to nickel of all studied organs. The same observation was made when 63Ni[II]-incorporation was carried out by 7 daily injections. In both experiments, kidneys take the second place in the relative distribution of nickel. For the studies of Ni-binding proteins in lung and liver cytosols, three different types of 63Ni[II]-incorporation were performed: (i) in vitro incorporation, (ii) kinetic study of in vivo incorporation where the animals were sacrificed after 30 min, 1, 2 and 4 h after a single i.p. injection of 63NiCl2, (iii) in vitro incorporation by 7 daily i.p. injections of 63NiCl2 with sacrifice of the animals 24 h after the last injection. Several Ni-binding proteins could be observed without regard to the type of incorporation performed. In liver cytosol most of these proteins can be revealed in vitro as well as in vivo. The in vivo labelled proteins are not the same at the beginning of the incorporation (30 min) and after an elapsed period (1 to 2 h). In lung cytosol in vitro and in vivo incorporation gave different results: although an intense labelling occurs after in vitro incubation, only few proteins are labelled after in vivo incorporation, two of which are only revealed after continuous exposure to 63Ni[II]. Most of the labelled proteins of lung and liver cytosols can be recovered after different fractionation experiments. These investigations confirm that nickel is preferentially bound to lung and demonstrate that nickel-incorporation is different in lung and in liver cytosols. It is shown here that several cellular proteins are implicated in the nickel-transport. The evolution of this phenomenon suggests the existence of a nickel-metabolism in the cell.

Structures of fifteen oligosaccharides isolated from new-born meconium.

New born meconium contains at least a hundred oligosaccharides. In this study the isolation and characterization of the major constituents is described. The structure elucidation of 15 neutral and acidic oligosaccharides was carried out by methylation analysis, mass spectrometry and 360-MHz 1H-NMR spectroscopy. The results show that the oligosaccharides accumulating in human meconium are probably products of the catabolism of the O- and N-linked carbohydrate chains of glycoproteins. It is proposed that endo-N-acetyl-alpha-D-galactosaminidase, endo-beta-D-galactosidase and endo-N-acetyl-beta-D-glucosaminidase are involved in the production of these compounds.

Structure of seven oligosaccharides excreted in the urine of a patient with Sandhoff's disease (GM2 gangliosidosis-variant O).

The urine of a patient with Sandhoff's disease (GM2 gangliosidosis-variant O) contains 10--12 N-acetylglucosamine-rich oligosaccharides in high amounts. The structures of seven of these have been determined: beta-GlcNAc(1--2)-alpha-Man-(1--3)-beta-man-(1--4)-GlcNAc; beta-GlcNAc-(1--4)-alpha-Man-(1--3)-beta-Man-(1--4)-GlcNAc; beta-GlcNAc-(1--2)-alpha-Man-(1--6)-beta-Man-(1--4)-GlcNAc; beta-GlcNAc-(1--4)-alpha-Man-(1--6)-beta-Man-(1--4)-GlcNAc; beta-GlcNAc-(1--2)-alpha-Man-(1--3)-[beta-GlcNAc-(1--2)-alpha-Man-(1--6)]beta-Man-(1--4)-GlcNAc; beta-GlcNAc-(1--2)-alpha-Man-(1--3)[beta-GlcNAc-(1--2)-alpha-Man-(1--6)][beta-GlcNAc-(1--4)]beta-Man-(1--4)-GlcNAc; beta-GlcNAc-(1--2)-alpha-Man(1)-(1--3)[beta-GlcNAc-(1--2)-alpha-Man(2)-(1--6)]beta-Man-(1--4)-GlcNAc, with additional beta-GlcNAc, with additional beta-GlcNAc-(1--4) on mannose (1) or (2). An unusual oligosaccharide, with a tri-branched beta-mannose, has been characterized as the major component excreted in urine.