Liver intoxication

Some authorities question whether dmnkeimess can result from the inhalation of ethyl alcohol vapors. Experience has demonstrated that in any event such intoxication is indeed rare (281). There is no concrete evidence that the inhalation of ethyl alcohol vapor will cause cirrhosis. Liver function is definitely impaired during alcohol intoxication (282), making the subject more susceptible to the toxic effects of chlorinated hydrocarbons. 

The ability to identify and quantify cyanobacterial toxins in animal and human clinical material following (suspected) intoxications or illnesses associated with contact with toxic cyanobacteria is an increasing requirement. The recoveries of anatoxin-a from animal stomach material and of microcystins from sheep rumen contents are relatively straightforward. However, the recovery of microcystin from liver and tissue samples cannot be expected to be complete without the application of proteolytic digestion and extraction procedures. This is likely because microcystins bind covalently to a cysteine residue in protein phosphatase. Unless an effective procedure is applied for the extraction of covalently bound microcystins (and nodiilarins), then a negative result in analysis cannot be taken to indicate the absence of toxins in clinical specimens. Furthermore, any positive result may be an underestimate of the true amount of microcystin in the material and would only represent free toxin, not bound to the protein phosphatases. Optimized procedures for the extraction of bound microcystins and nodiilarins from organ and tissue samples are needed. 

Hepatic Effects. Liver lesions have been reported in humans acutely intoxicated by methyl parathion formulation (Wolfatox) (Fazekas 1971 Fazekas and Rengei 1964). These studies are discussed in detail in Section 3.2.2.1. Liver lesions were hepatocellular swelling, degeneration, and fatty change. 

Intoxicated patients surviving for 28 hours to 9 days had hepatocytes free in central or hepatic veins this finding was described as mobilization of liver cells. The role of methyl parathion in the induction of all of these lesions is unclear. 

The ammonia produced by enteric bacteria and absorbed into portal venous blood and the ammonia produced by tissues are rapidly removed from circulation by the liver and converted to urea. Only traces (10—20 Ig/dL) thus normally are present in peripheral blood. This is essential, since ammonia is toxic to the central nervous system. Should portal blood bypass the liver, systemic blood ammonia levels may rise to toxic levels. This occurs in severely impaired hepatic function or the development of collateral links between the portal and systemic veins in cirrhosis. Symptoms of ammonia intoxication include tremor, slurred speech, blurred vision, coma, and ultimately death. Ammonia may be toxic to the brain in part because it reacts with a-ketoglutarate to form glutamate. The resulting depleted levels of a-ketoglutarate then impair function of the tricarboxylic acid (TCA) cycle in neurons. 

Of particular interest in brevetoxin research are the diagnosis of intoxication and identification of brevetoxins and their metabolites in biological fluids. We are investigating the distribution and fate of radiolabeled PbTx-3 in rats. Three model systems were used to study the toxicokinetics and metabolism of PbTx-3 1) rats injected intravenously with a bolus dose of toxin, 2) isolated rat livers perfused with toxin, and 3) isolated rat hepatocytes exposed to the toxin in vitro. 

Bautista, A.P. and Spitzer, J.J. (1992). Acute ethanol intoxication stimulates superoxide anion production by in situ perfused rat liver. Hepatology 15, 892-898. 

Sinaceur, J., Ribiere, C., Sabourault, D. and Nordmann, R. (1985). Superoxide formation in liver mitochondria during ethanol intoxication possible role in alcohol toxicity. In Free Radicals in Liver Injury (eds. G. Poli, K.H. Cheeseman, M.U. Dianzani and T.F. Slater) pp. 175-177. IRL Press, Oxford. 

Ohya I, Komoriya H, Bunai Y. 1985. [Discoloration of surface of the brain and liver in a case of fatal hydrogen sulfide intoxication.] Research and Practice in Forensic Medicine 28 119-123. (Japanese)... 

Iron appeared to reduce the effects of orally or subcutaneously administered lead on blood enzyme and liver catalase activity (Bota et al. 1982). Treatment of pregnant hamsters with iron- or calcium-deficient diets in conjunction with orally administered lead resulted in embryonic or fetal mortality and abnormalities (ranting, edema) in the litters, while treatment with complete diets and lead did not (Carpenter 1982). Inadequate levels of iron in association with increased body burdens of lead enhanced biochemical changes associated with lead intoxication (Waxman and Rabinowitz 1966). Ferrous iron was reported to protect against the inhibition of hemoglobin synthesis and cell metabolism by lead it has been speculated that iron competes with lead uptake by the cell (Waxman and Rabinowitz 1966). In... 

Giurgea R, Baba I, Haller J, et al. 1989. Modifications in the liver and thymus of Wistar rats intoxicated with lead. Revue Romaine de Biologie Serie Biologie Animale 34 113-115. 

There are over 400 constituent compounds in marijuana. More than 60 of these are pharmacologically active cannabinoids, of which 4 are the most important. The most psychoactive is delta-9-tetrahydrocannabinol (A-9-THC). The other three important natural cannabinoids are A-8-THC, cannabinol and cannabidiol (Kumar et al., 2001). In addition, some of the metabolites of THC, such as 11-hydroxy-A-9-THC, are also psychoactive. As a consequence and contrary to many other drugs, the metabolism of THC in the liver does not decrease intoxication, rather it prolongs it. 

Dwivedi, R.S., G. Kaur, R.C. Srivastava, and C.R.K. Murti. 1985a. Metabolic activity of lysosomes in tin-intoxicated regenerating rat liver. Toxicol. Lett. 28 133-1.118. 

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