Different Forms of Vanadate on Sugar Transport in Insulin Target and Nontarget Cells

The effects of several vanadates (ie, orthovanadate, pervanadate, and two stable peroxovanadium compounds) on basal and insulin-stimulated 2-DG transport in insulin target and nontarget cell lines are reported, herein. In nontarget cells, exposure to vanadates (5 × 10(−6) to 10(−4) mol/L) resulted in 2-DG transport stimulatory responses similar to those observed in 2-DG transport post exposure to 667 nmol/L insulin alone, or insulin in combination with vanadates. In 3T3-L1 adipocytes and L6 myotubes, exposure to a vanadate compound or 67 nmol/L insulin, stimulated 2-DG transport dramatically. Again, this effect on stimulated transport was similar to 2-DG transport post-treatment with the effective vanadates in combination with insulin. While pervanadate or stable peroxovanadates stimulated 2-DG transport at 10(−5) to 10(−6) mol/L, orthovanadate up to 10(−4) mol/L was not effective in stimulating 2-DG transport in any of the cell lines tested. The data indicate that the various peroxovanadates are clearly superior insulin mimetics while a more limited insulin mimesis is observed with orthovanadate over a wide variety of cell types

Studies of cellular sensitization to myelin antigens in multiple sclerosis: Dissociation of MIF and LBT production in response to a peptide encephalitogenic in rhesus monkeys

The macrophage migration inhibitory factor (MIF) assay and the lymphoblastic transformation (LBT) technique were utilized simultaneously to measure immune responses to peptide Y, the 17 amino acid C-terminal fragment of basic myelin protein, in patients with multiple sclerosis (MS). Ten normals and 67 MS patients from the Montreal Neurological Hospital and affiliated institutions were examined. A prospective attempt was made to correlate the measured responses with phasic clinical activity of the disease. The LBT results indicate some degree of cellular sensitization to peptide Y which parallels the clinical course of the illness, and resembles earlier positive findings obtained with the whole basic myelin protein molecule. These findings, however, are in contrast to a negative MIF response to the Y peptide used in the present study and further contrast the positive MIF results obtained earlier using the whole protein. It is not evident from the results of the present study whether sensitization may be of any pathogenetic significance, but the findings show that differing portions of the basic myelin protein molecule may selectively stimulate specific lymphokine elaboration by sensitized lymphocytes