Human metabolism, effects

Smedman, A., and Vessby, B. (2001) Conjugated Linoleic Acid Supplementation in Humans—Metabolic Effects, Lipids 36, 773-781. 

Metabolic Effects. Severe metabolic acidosis with high anion gap and hyperglycemia was reported in humans after acute poisoning with endosulfan (Blanco-Coronado et al. 1992 Lo et al. 1995). In five of the six cases reported by Blanco-Coronado et al. (1992), the metabolic acidosis was corrected with gastric lavage with activated charcoal and intravenous sodium bicarbonate and diazepam. No further information regarding metabolic effects in humans after exposure to endosulfan was located. 

Comparative Toxicokinetics. In humans, the targets for trichloroethylene toxicity are the liver, kidney, cardiovascular system, and nervous system. Experimental animal studies support this conclusion, although the susceptibilities of some targets, such as the liver, appear to differ between rats and mice. The fact that these two species could exhibit such different effects allows us to question which species is an appropriate model for humans. A similar situation occurred in the cancer studies, where results in rats and mice had different outcomes. The critical issue appears to be differences in metabolism of trichloroethylene across species (Andersen et al. 1980 Buben and O Flaherty 1985 Filser and Bolt 1979 Prout et al. 1985 Stott et al. 1982). Further studies relating the metabolism of humans to those of rats and mice are needed to confirm the basis for differences in species and sex susceptibility to trichloroethylene s toxic effects and in estimating human heath effects from animal data. Development and validation of PBPK models is one approach to interspecies comparisons of data. 

Birnboim, H.C. (1988). A superoxide anion induced DNA strand-break metabolic pathway in human leukocytes effect of vanadium. Biochem. Cell. Biol. 66, 374-381. 

Metabolic Effects. No reports were located regarding metabolic effects in humans following acute-, intermediate-, or chronic-duration inhalation exposure to americium. 

No data were located regarding respiratory effects, cardiovascular effects, gastrointestinal effects, hepatic effects, renal effects, endocrine effects, dermal effects, ocular effects, body weight effects, or metabolic effects in humans or animals following acute-, intermediate-, or chronic-duration dermal exposure to americium ... 

Metabolic Effects. Metabolic effects have not been reported in humans after exposure to -hexane. In animal studies where metabolic parameters (blood pH, electrolytes, glucose) were measured, no effects were seen after inhalation exposure to -hexane in rats at up to 10,000 ppm for 6 hours a day, 5 days a week for 13 weeks (Cavender et al. 1984) or in B6C3Fj mice similarly exposed (Dunnick et al. 1989 ... 

For the last forty years, many reports have emerged on the hormone-like effects of chemical compounds such as pesticides and industrial chemicals upon wildlife and humans. The effects of these materials are believed to be either direct or indirect. Direct effects involve positive or negative interactions with the hormone receptors. Indirect effects may result when the synthesis of hormones or their receptors is altered, or the transport, metabolism, or elimination of hormones is modified in some way. The discovery of hormone-like properties of some compounds was made long after their release into the environment. It was shown soon after their introduction that aviation crop dusters handling DDT had low sperm counts and workers at a plant producing the insecticide kepone were reported to have low libido, sperm counts and to be impotent. Subsequently, experiments conducted in laboratory animals demonstrated unambiguously the oestrogenic activity of these pesticides. 9 refs. 

In attempting to reconcile these findings, it should be pointed out that rats may not be appropriate models for the study of calcium metabolism in humans. Unlike humans, the rat does not undergo epiphyseal plate closure and does not have a significant haversian remodeling sequence (21) Furthermore, rats excrete only l-270 of their calcium intake in their urine whereas humans excrete approximately 20-30% or more. This fact is especially significant, since most of the known effects of phosphates on calcium retention in humans are effected by alterations in urinary calcium. 

We have conducted two human metabolic studies (5,6) to compare the effects of increasing phosphorus intake on calcium utilization in healthy young adults maintained at low (ca. 400 mg/day) and high (ca. 1200 mg/day) levels of calcium intake. Increasing dietary phosphorus, as orthophosphate, caused a slight reduction in fecal calcium and a substantial reduction in urinary calcium losses (Table III). 

Primary hepatocytes are a common in vitro system to evaluate metabolism, toxicity and enzyme induction [67-69]. Human hepatocytes are considered the most relevant system to evaluate or predict human metabolism or effects of a new dmg. A significant... 

Human Health At present, studies on the impact of POPs on human health are very limited in China. Most of the existing literature is focused on dietary studies, as the food chain is considered a major pathway for POPs to effect human health. Information on human health effects such as body burden and metabolism is insufficient and generally extrapolated from modeling data because few doctors have been involved in research on POPs exposures in China. Other exposures through respiration and skin as well as air and soil are seldom studied. 

D. K. Monteith, S. C. Storm, A Comparison of the Inhibition of Deacetylase in Primary Cultures of Rat and Human Hepatocytes Effecting Metabolism and DNA-Binding of 2-Acetylaminofluorene , Cell Biol. Toxicol. 1990, 6, 269-284. 

Blin J, Piercey MF, Giuffra ME, Mouradian MM, Chase TN. (1994). Metabolic effects of scopolamine and physostigmine in human brain measured by positron emission tomography. J Neurol Sci. 123(1-2) 44-51. 

No studies were loeated regarding respiratory, hematological, hepatic, renal, or body weight effects in humans after oral exposure to 3,3 -dichlorobenzidine. No studies were located regarding cardiovascular, gastrointestinal, musculoskeletal, endocrine, dermal, ocular, or metabolic effects in hmnans or animals after oral exposure to 3,3 -dichlorobenzidine. 

Metabolic Effects. No studies were located regarding metabolic effects in humans or animals after exposure to 3,3 -diehlorobenzidine by any route. However, since this effeet was not reported in any of the existing epidemiologieal and animal studies, it is imlikely that metabolie effeets will oeem in hmnans exposed to 3,3 -dichlorobenzidine at levels found at hazardous waste sites. 

Absorption, Distribution, Metabolism, and Excretion. Available data are insufficient to allow accurate evaluation of absorption, metabolism, or persistence of 3,3 -dichlorobenzidine in human tissues. Additional studies to identify and quantify metabolites of 3,3 -dichlorobenzidine in humans and animals would be useful in establishing the relevance of animal studies in predicting human health effects. Metabolic handling of 3,3 -dichlorobenzidine in humans needs to be better characterized before urinary levels of the compound or its metabolites can be used to quantitate human exposure. 

No reports were located in which cardiovascular, musculoskeletal, dermal, ocular, or metabolic effects were associated with oral exposure of humans or animals to chlorine dioxide or chlorite. 

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