Endotoxin biological effects

Antweller ( ) in 1961 injected Salmonella abortus equl and E. coll endotoxins Intraperltoneally into rats and looked for mast cells in the mesentery and the histamine content of the abdominal fluid. Negative results were obtained with amounts of the endotoxins (up to 10 yg) thought to be similar to that in cotton dust although large doses of endotoxin were known to cause rapid histamine release in cats and dogs. He concluded that endotoxins did not produce histamine release or the biological effect of cotton dust extracts. 

Endotoxin. A heat-stable bacterial toxin not freely liberated into the surrounding medium. Endotoxins are released only when the integrity of the cell wall is disturbed, are less potent than most exotoxins, are less specific, and do not form toxoids. When injected in large quantities, endotoxins produce hemorrhagic shock and severe diarrhea. Smaller amounts cause fever, altered resistance to bacterial infections, leukopenia followed by leukocytosis, and numerous other biological effects. 

Toxicity is the property or properties of a material that produces a harmful effect upon a biological system. A toxicant is the material that produces this biological effect. The majority of the chemicals discussed in this text are of man-made or anthropogenic origin. This is not to deny that extremely toxic materials are produced by biological systems venom, botulinum endotoxin, and some of the fungal aflatoxins are extremely potent materials. However, compounds that are derived from natural sources are produced in low amounts. Anthropogenically derived compounds can be produced in millions of pounds per year. 

WolffSM. 1973. Biological effects of bacterial endotoxins in man. J. Infect. Dis. 128(Suppl.) 733... 

It is too early to definitively identify the molecular mechanism(s) by which CLA, or specific isomers thereof, modulate immune reactivity and reduce disease. Peroxisomal proliferator-activated receptor-y (PPAR-y) activation has been proposed as a mechanism by which CLA exerts some of its biological effects (23). Although PPAR-y may play a role in some of the effects caused by dietary CLA, and these effects could be mediated via the downregulation of the NFkB pathway (24), there are some inconsistencies in the isomer-specific effects on the regulation of COX-2 and some of the products of the NFkB pathway. For example, Yu et al. (23) demonstrated that both the t9,cll and the tl0,cl2 isomers of CLA increase PPAR-y, and decrease TNFa however, only the c9,tll isomer decreased endotoxin-induced TNFa (12). If CLA-fed animals are more resistant to endotoxin (above) and if endotoxin downregulates PPAR-y (24), could PPAR-y regulation explain the wide array of effects attributed to dietary CLA ... 

The antiviral and antitumor activity as well as the lymphocyte activation and modulation of the sensitivity to bacterid endotoxine are biological effects of DIVEMA based on the modification of the immunological responsiveness of the organism. Because of its antitumor activity, DIVEMA has been included under the code number NSC 46015 in a broad antitumor testing. Later it was found that the original NSC 46015 preparation was polydisperse and more narrow fractions were used It can be concluded from these studies that the activation of macrophages to kill the tumor cells is the predominant if not the only mechanism of antitumor activity of DIVEMA This is very probably true for many other synthetic polymers that... 

In humans, contact with LPS may occur not only during a bacterial infection but also via LPS-contaminated medicaments and solutions administrated intravenously (parenteralia). Since the biological effects of LPS may appear even at concentrations of 1 ng per 1 kg of body weight, drugs intended for parenteral use, have to be endotoxin-free , i.e., thoroughly depyrogenated. In fact parenteralia have to comply with LPS threshold limits (in EU , endotoxin unit) regulated by pharmacopoeias. For example, tetracycline hydrochloride may not contain more than 0.5 ELf/mg. Similar limits exist for insulin (0.8 EU/insulin unit), hyaluronidase (2.3 EU/ hyaluronidase unit), the sodium salt ofheparin for injection (0.003 EU/heparin unit). ... 

Doran JE. Biological effects of endotoxin. Curr Stud Hematol Blood Trans 1992 66-99. 

SWAIN p, NAYAK SK, NANDA PK, DASH s (2008), Biological effects of bacterial lipo-polysaccharide (endotoxin) in fish a review . Fish Shellfish Immunol, 25, 191-201. 

A link between bacteria and tumor therapy was found early, at the beginning of the XVIII century [10]. By the end of the XIX century, Coley [11] developed a treatment for cancer with a mixture of bacterial toxins. In 1943 Shear and Turner [4] found that the antitumor effect of Coley s toxin was due to endotoxins, and after several decades it was shown that the biological activity of LPS was due to the lipid A [5]. We investigated the structures of lipids A with regard to their antitumor activities [12], finding that the optimum in vivo activity is obtained with diglucosamines acylated by 3 long chain fatty acids. 

The biological properties associated with the polysaccharides are those relating to serological specificity, and, at least to some extent, they serve as bacteriophage receptors. The somatic antigens are also referred to as Endotoxins, but their toxic properties and manifold physiological effects are due to the lipide component, and this subject has been adequately reviewed. ... 

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