The effect of light on the toxicity of paraquat in the mouse

The role of light is known to be important in the herbicidal action of paraquat, the active ingredient of Gramoxon. Experiments were therefore performed to establish whether illumination influences paraquat toxicity in some way in mice. Besides the 72-hr survival rate, studies were made of the body weight/lung weight ratio, the antioxidant enzyme activity and the lipid peroxidation in mice treated with the LD50 of paraquat and kept in the dark or under illumination. All of the measured parameters indicate that illumination enhances the toxic properties of paraquat in mice.

Effects of ascorbic acid in vivo on the fatty acid composition of the tissues of mice treated with Gramoxone

The effects of the simultaneous administration of ascorbic acid and the LD50 of paraquat (an ingredient of Gramoxone), and of ascorbic acid pretreatment followed by the LD50 of paraquat, were studied on the phospholipid and triglyceride fatty acid levels in homogenates of mouse lung, liver and kidney. Ascorbic acid treatment increases the content of polyunsaturated fatty acids in the lung considerably, i.e. the pulmonary membrane fluidity decreases significantly in response to ascorbic acid. In the liver homogenate, the membrane fluidity is significantly increased by ascorbic acid pretreatment, and significantly decreased by simultaneous ascorbic acid treatment. In the renal tissue, the result of ascorbic acid pretreatment exhibits a similar tendency to that of paraquat treatment, but a more significant one, while the administration of ascorbic acid together with paraquat does not cause a substantial change in the fluidity index compared to the control.

The fatty acid content of the Bordetella pertussis endotoxin

The fatty acid content of Bordetella pertussis endotoxin has been estimated by several methods. Expressed as 3-hydroxytetradecanoic acid, it was 0.74 mumol (mg lyophilized material)-1, 0.38 mumol being ester-bound, and 0.32 mumol in amide linkage. Reported molar ratios of ester-bound to amide-bound fatty acids in endotoxins of various bacterial species range from 2.4 to 2 in B. pertussis, to 5 to 2 in Salmonella minnesota; according to these figures large differences must exist in the degree of substitution, and the substitution pattern of the glucosaminyl-beta-1,6-glucosamine unit present in the hydrophobic region of endotoxins. When fatty acids, released by acid and alkaline hydrolyses of the B. pertussis endotoxin, were extracted into chloroform, unidentified chromogenic substances appearing in the extract interfered with their colorimetric estimation; no interference was observed when hexane was used instead of chloroform.

Effects of various thiols on paraquat toxicity

It was demonstrated that cysteine and D-penicillamine are able to replace reduced glutathione to some extent in the glutathione peroxidase reaction. An in vivo study was made of the role played by--SH compounds in the antioxidant enzyme system involved in the detoxication of the LD50 of paraquat (PQ), and hence of their role in the detoxication of PQ. The effectiveness was D-PA greater than GSH greater then Cys in the liver and GSH greater than Cys greater than D-PA in the lung.

Chemical synthesis and immunological activities of glycolipids structurally related to lipid A

Complete chemical syntheses of a number of monosaccharides derived from 2-deoxy-2-[(3R)-3-hydroxytetradecanamido]-D-glucopyranose and structurally related to the hydrophobic moiety (lipid A) of several bacterial endotoxins are described. Selected humoral (complement activation) and cellular (mitogenicity and induction of interleukin 1 production) in vitro activities of a lipid A preparation obtained from the Bordetella pertussis endotoxin were compared with those of ten of these monosaccharides and with those of previously synthesized, analogous disaccharides. Results show that each of these in vitro activities of the lipid A preparation can be efficiently induced by at least one of the monosaccharide derivatives.

Investigations on the chemistry of berbanes. 10. Synthesis of raunescinone analogues with hypotensive and antihypertensive activity

The pharmacologically active (methylenedioxy)- and diethoxyepialloberbane keto esters I have been synthesized with use of the readily available keto esters 2 as starting material. By choice of the appropriate reaction sequence both antipodes of keto ester 2a can be employed to provide any enantiomer of the desired raunescinone analogue 1a. Hypotensive, antihypertensive, and central depressant effects of 1a are described. The principle effect observed for 1a was a potent hypotensive and antihypertensive effect of long duration without depression of the central nervous system.

Interleukin 1 secretion by human monocytes stimulated by the isolated polysaccharide region of the Bordetella pertussis endotoxin

The isolated polysaccharide chain, PS-1, of the Bordetella pertussis endotoxin was examined by isoelectric focusing, SDS-polyacrylamide gel electrophoresis and gel filtration for heterogeneity and for possible contamination by the parent endotoxin. This polysaccharide, previously found to be a very potent, macrophage-dependent, polyclonal B-cell activator and to mediate the specific binding of the endotoxin to macrophages, stimulated the interleukin 1 (IL 1) secretion by human monocytes; its potency was similar to that measured for the endotoxin. It was concluded that endotoxin-induced IL 1 production may be initiated by the interaction of the polysaccharide chain of the B. pertussis endotoxin and a specific structure present on macrophages.

Effects of paraquat on peroxide metabolism enzymes and lipid peroxidation in the rat

Investigation has been made of how the LD50 and LD100 of PQ influence the peroxide metabolism enzymes and lipid peroxidation in organ homogenates and blood samples of the rat. The peroxide metabolism enzyme activities were changed in a concentration dependent manner. In general, the effect of the lower doses of PQ on the superoxide dismutase, catalase activities and lipid peroxidation are increased. The glutathione peroxidase activity was decreased. Higher doses of PQ enhanced all of enzyme activities and lipid peroxidation studied.

Heme oxygenase activity is decreased by D-penicillamine in neonates

A 3-day D-penicillamine treatment of neonatal rats caused a significant decrease in heme oxygenase activity. This change was not observed in adult rats. The data indicate age-related differences in the effects of D-penicillamine.

Changes induced by Gramoxon in tissue phospholipids and phospholipid fatty acids in mouse and guinea-pig

Following administration of the LD50 or the LD100 of Gramoxon (PQ), the phospholipids (PL) of the lung, liver and kidney were separated and both the PLs and the fatty acids isolable from them were examined quantitatively. The different doses of PQ caused different changes of the saturated and unsaturated fatty acids in the various organs. The changes in the PL unsaturated fatty acids point to PQ-induced lipid peroxidation enhancement and membrane damage.

Some further data on the effects of two organophosphate pesticides on the oxidative metabolism in the liver

Sumithion is the most active cholinesterase inhibitor. The cholinesterase inhibiting action of the organophosphates (OPs) is better compensated by vitamin E in normal animals, but by vitamin A in vitamin A-deficient animals. The lipid peroxidation (LP) is enhanced by the antioxidant vitamins in the liver of normal rats; although they decrease it in the liver of vitamin A-deficient animals, in no case do they prevent the LP-enhancing effect of the OPs examined. The OPs examined inhibit protein synthesis in the liver of vitamin A-deficient animals.

Effects of neuroleptics on the lipid peroxidation and peroxide metabolism enzyme activities in various discrete areas of the rat brain

The effects of a 7-day treatment with Haloperidol or reserpine (in both cases 0.1 mg/kg per day) were studied on the superoxide dismutase and catalase activities and the lipid peroxidation in various discrete regions of the rat brain. It was found that these neuroleptics change the lipid peroxidation and the activities of the enzymes in similar directions in the brain areas tested.

Altered peroxide metabolism in erythrocytes from children with cystic fibrosis

The superoxide dismutase and catalase activities and the lipid peroxidation values in the blood of healthy volunteers were compared with those of children of various ages and of both sexes with cystic fibrosis and with those of the heterozygous parents of these children. The red blood cell superoxide dismutase and catalase activities in children with cystic fibrosis and in their parents are significantly increased. At the same time, the lipid peroxidation of the red blood cells (the quantity of thiobarbituric acid reactive substance) is significantly reduced.