Abstract
In most species the LD50 of triethylene glycol dinitrate (TEGDN) is two to five times as high as that of propylene glycol dinitrate (PGDN). Both compounds produce methemoglobinemia and hypotension in rats. However, TEGDN-poisoned rats tremor violently and expire, apparently in respiratory arrest, after acute convulsive episodes. PDGN-poisoned rats are lethargic and do not convulse. In Vitro TEGDN at concentrations above 1.5mM blocks nerve-stimulated contraction of a phrenic nervediaphragm preparation, and this interference with nerve-muscle communication appears to be the cause of the tremoring. Chronic daily dermal applications to rabbits of 21 mmoles/kg of both dinitrates cause death in 2 to 3 weeks. PGDN-treated rabbits gain weight normally, while those treated with TEGDN lose 20 to 30% of their body weight. Guinea pigs receiving as little as 100 nig/kg of TEGDN ip daily have decreased food intake and retarded weight gain. The toxic responses 0 these two dinitrates are therefore sufficiently different to preclude simple comparisons in hazard evaluations.