The Toxicity of Low‐molecular Triglycerides.

Abstract

Summary. The LD50 of low‐molecular triglycerides has been determined by intravenous injection into mice. The triglycerides were administered in the form of emulsions. The LD50 is found to be lowest in triisovalerin (82 ± 4 mg/kg) and to increase when the fatty acid chain contains less than 5 carbon atoms, reaching 1,600 ± 81 mg/kg in triacetin. With more than 5 carbon atoms in the fatty acid chain, LD50 rises successively and lies over 10,000 mg/kg for trinonylin, tricaprinin and triunde‐cylin. With lethal doses the symptom complex is somewhat variable, but generally includes respiratory arrest or respiratory embarrassment with a rapid onset, this being the probable cause of death.

Tissue‐specific distribution and whole‐body burden estimates of persistent organic pollutants in the bottlenose dolphin (Tursiops truncatus)

“…Chem. 29,2010tions were calculated from the slope and y intercept generated by at least a three-point calibration curve. …”

“…The authors proposed that the melon does not serve as an energetic reserve because short-chain fatty acids are not significant sources of metabolic energy and melon lipids are of critical importance in maintaining acoustic function, and therefore should be preserved at all cost [31]. Mobilization of melon lipids is also unlikely due to its high concentrations of isovaleric acid, a fatty acid that has proven toxic when introduced into the circulation of other mammalian species [29][30][31]. In comparison, blubber lipids typically consist of longer-chain, unsaturated, straight fatty acids [36,37].…”

“…Although both blubber and the melon consist predominantly of neutral lipids such as triacylglycerols, the fatty acid composition of the melon is unique, consisting of short-and medium-chain (C5-C12), branched, saturated fatty acids specialized for sound transmission [21,24,28]. A major constituent of melon fatty acids, isovaleric acid, has been associated with toxic effects-vomiting, convulsions, coma, death-when introduced into circulation of other mammalian species [29,30]. Thus, it is probable that melon lipids are synthesized in situ and are not mobilized into circulation in response to energetic demands, as are blubber lipids [21,31].…”

Function and evolution of specialized endogenous lipids in toothed whales

“…The accumulation of i-5:0 in the blood of patients with isovaleric acidemia causes a suite of neurological abnormalities (severe mental deficiencies, convulsions and coma), and is fatal in 50% of patients if not treated within two weeks of birth (Nyhan, 1984). Wretlind (1957) demonstrated that i-5:0 was highly toxic to mice, having a lower LD 50 compared with that of other short chains. The specific mechanisms of its toxicity are not well known, but i-5:0 is known to produce coma and EEG changes, and to inhibit mitochondrial respiration (Haas and Stumpf, 1981).…”

Life history constrains biochemical development in the highly specialized odontocete echolocation system

“…Rather than being produced via the sequential addition of two-carbon units in the liver, these FA are believed to be synthesized as intermediates in amino acid degradation (Morii & Kaneda 1982). i-5 : 0 is highly toxic to other mammals ( Wretlind 1957;Tanaka et al 1966), and in fact the only mammals in which this molecule is known to accumulate are human patients suffering from isovaleric acidemia, a heritable disease that can be fatal ( Tanaka et al 1966). Yet in some odontocete acoustic fats, i -5 : 0 can comprise more than two-thirds of all FA present (Koopman et al 2003(Koopman et al , 2006.…”