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In 3T6 mouse fibroblast cultures, ascorbate has two separate roles in the hydroxylation of collagen proline. In one of these, its co-factor role in vitro, it can be replaced by a variety of reducing agents, notably low molecular weight thiol compounds; the latter however also cause irreversible inactivation of the enzyme. In its second role, ascorbate appears to act in the same manner as high lactate concentration and high cell density: by catalysing the formation of active enzyme inside the cell. Reduction in oxygen tension, an uncoupling agent and several other circumstances, can also produce this effect. The in vivo activation effect seems to be largely responsible for the stimulation of proline hydroxylation by ascorbate in growing cultures.

Macaluso-Aleo G. I primi passi del l'Italia in Africa. In: Revue d'histoire des colonies, tome 20, n°88, Juillet-août 1932. pp. 289-368.

The effect of sodium salicylate on the metabolism of 3T6 fibroblasts treated with the lathyrogen β-aminopropionitrile was studied. A 5 mM concentration of the lathyrogen and/or 0.5 mM sodium salicylate was used to study proliferation, collagen synthesis, and mucopolysaccharide synthesis as measured by 35SO4 incorporation. Sodium salicylate was able to reverse all lathyrogen-mediated changes to control or near control values. The diversity of these biosynthetic activities suggests that the influence of sodium salicylate on lathyrogen-treated cells is a result of a general metabolic effect rather than a specific one; the exact mechanism of action remains unknown.

The lathyrogen, beta-aminopropionitrile (BAPN), in ascorbate-free medium increased the synthesis of both collagenous and non-collagenous proteins in 3T6 fibroblasts. Cell layer collagen was underhydroxylated and more easily extracted with neutral salt in treated cultures. The ratios of proline: hydroxyproline in sequentially extracted collagen in the cell layer of both BAPN and control cultures showed virtually no difference in the acid soluble and insoluble fractions; however, the BAPN salt-soluble fraction was definitely underhydroxylated when compared to control cultures. The data suggest that the salt-soluble macromolecule represents, in addition to a cross-linking defect, an underhydroxylated intracellular collagen precursor.

Enterobacter aerogenes was examined for its ability to utilize a known lathyrogen or chemically related compounds for use in developing an in vitro model system to study experimental lathyrism. Enterobacter aerogenes grew in a minimal medium containing the lathyrogen, beta-aminopropionitrile fumarate. Related compounds or combinations of related compounds which together contained all the constituents of the lathyrogen failed to support growth. The specificity of this compound in supporting growth of this polysaccharide-producing microorganism suggests that this microorganism may be useful in developing an in vitro model system to study polysaccharide metabolism in experimental lathyrism.

SummaryThe exposure of 3T6 fibroblasts to the lathyrogen β-aminopropionitrile fumarate caused a reduction in proliferation of the cells but had no effect upon viability. Chemical analysis for the production of collagen as measured by free, peptide, and protein-bound hydroxyproline showed that the lathyrogen exerted a stimulative effect. The lathyrogen-treated cells produced approximately twice the amount of hydroxyproline as did the control cells. The data also indicate that the initial stages of collagen production are not altered and that the depression in proliferation signifies a change in overall metabolism rather than a direct toxic effect.

The purpose of this investigation was to compare the relative cytotoxic effects of methyl 2-cyanoacrylate, isobutyl 2-cyanoacrylate, and n-octyl 2 cyanoacrylate. Filter paper disks were saturated with these monomers and placed on monolayers of L-929 fibroblasts. Plates containing the cells and disks were incubated and observed at various intervals. zones of cytotoxicity appeared first around the methyl-saturated disks. The cytotoxic response was greatest to the methyl-saturated disks and less severe to the isobutyl and octyl disks. This is in agreement with previous in vivo investigations.

An assay-plate assembly has been described to be used in tissue culture for screening solid materials for toxicity, as well as for testing the cytotoxicities of various liquids such as antibiotics, anticancer agents and miscellaneous chemicals. This apparatus, in which the test sample is completely immobilized and is in direct contact with the cell monolayer, can be used for testing objects of any shape or density.

β-Aminopropionitrile verhindern wirkungsvoll die zellulare Einlagerung vonβ-Alaninen (strukturmassig zu den Aminosauren gehorend) in grosser Konzentrationsbreite. Aus diesem Grunde wirken Lathyrogene als Antagonisten durch Veranderung der zellularen Konzentration der Analogen. Die veranderten Produkte haben wahrscheinlich eine abnorme Funktion und die Erkrankung zur Folge.

Fur 11 bekannte lathyrogenische Substanzen wurden In-vitro-Modellsysteme entwickelt. Die gunstigste Dosierung entsprach der hochsten atoxischen Konzentration des Lathyrogens.