Immunosuppressive effects of (2R,5R)-6-heptyne-2,5-diamine, an inhibitor of polyamine synthesis: II. Beneficial effects on the development of a lupus-like disease in MRL-lpr/lpr mice.

(2R,5R)-6-heptyne-2,5-diamine (MAP; MDL 72175), a potent irreversible inhibitor of L-ornithine decarboxylase (ODC), possesses immunosuppressive activities in vitro as the result of inhibition of lymphocyte polyamine biosynthesis. The effects of MAP were now studied in vivo in MRL-lpr/lpr female mice, an animal model for human systemic lupus erythematosus (SLE). Administration of MAP (0.

Immunosuppressive effects of (2R,5R)-6-heptyne-2,5-diamine an inhibitor of polyamine synthesis: I. Effects on mitogen-induced immunoglobulin production in human cultured lymphocytes.

The consequences of specific inhibition of polyamine biosynthesis by (2R,5R)-6-heptyne-2,5-diamine (MAP) a potent inhibitor of L-ornithine decarboxylase (ODC), on immunoglobulin (Ig) production were studied in cultured human peripheral blood lymphocytes stimulated with pokeweed mitogen (PWM). MAP inhibits the usual PWM-induced increase of polyamine (putrescine, spermidine and spermine) concentrations and reduces concomitantly cell replication. In parallel with these biochemical effects, IgG and IgM production are diminished, a 95% decrease being observed at 100 microM MAP concentration.

Post-translational modification of the protein-synthesis initiation factor eIF-4D by spermidine in rat hepatoma cells.

The rates of synthesis and turnover of the rare amino acid hypusine [N6-(4-amino-2-hydroxybutyl)-2,6-diaminohexanoic acid] in protein were studied in relationship to polyamine metabolism and growth rates in rat hepatoma tissue-culture (HTC) cells. Hypusine is selectively formed in the eukaryotic translation initiation factor eIF-4D, by a post-translational mechanism involving spermidine [Cooper, Park, Folk, Safer & Braverman (1983) Proc. Natl.

Effects of (2R, 5R)-6-heptyne-2,5-diamine, a potent inhibitor of L-ornithine decarboxylase, on rat hepatoma cells cultured in vitro.

DL-alpha-Difluoromethylornithine (F2MeOrn), the most widely-used inhibitor of L-ornithine decarboxylase, has been a useful tool to demonstrate that polyamine biosynthesis is required to maintain maximum rates of cell proliferation. However, in most eukaryotic cell systems, F2MeOrn exerts cytostatic rather than cytotoxic effects. This may be due to the fact that this inhibitor creates only incomplete polyamine deficiency.

Metabolism of N8-monoacetylspermidine in rat hepatoma cells. Investigation of its effect on the activity of L-ornithine decarboxylase.

Recent evidence has indicated a role for the acetyl derivatives of polyamines, particularly N8-monoacetylspermidine, as activators of L-ornithine decarboxylase in rat hepatoma tissue culture (HTC) cells. This is in contrast with the well-described negative regulatory control of ornithine decarboxylase exerted by their non-acetylated counterparts. Because of the possibility of a rapid extracellular and intracellular catabolism of the acetyl derivatives of polyamines, the metabolism of N8-monoacetylspermidine and its effect on HTC cell ornithine decarboxylase have been investigated, under conditions which eliminate its extracellular catabolism.