2.3- Dimercaptopropanol , effect acids

Coumarin, the lactone of o-hydroxycinnamic acid, and some of its derivatives have been isolated from many plant species 31). Thimann and Bonner 141) attributed the growth-inhibiting effects of coumarin to its action on enzyme sulfhydryl groups. Inhibitory effects of coumarin on Avena coleoptiles and pea stem sections could be overcome by 2,3-dimercaptopropanol (BAL). Coumarin has also been reported to disrupt mitosis 29,30). 

Lead is widely destributed in the environment, especially in industrial and urban areas, and it is readily absorbed into the mammalian body where it exerts a number of undesirable physiological effects. Its most dramatic action is the inhibition of human red cell 5-aminolaevulinic acid dehydrase activity71), but it also depresses the activities of many enzymes having functionsl -SH groups. Attempts to remove lead from the body using agents such as dimercaptopropanol can result in the formation of lipid-soluble lead complexes that may be carried to the brain and exacerbate the effects of lead poisoning. 

The mechanism of this eflFect is not known. Hill and Starcher (49) postulated that reduction of copper from its divalent (cupric) state to its monovalent (cuprous) state accounted for the impaired absorption of copper in the presence of ascorbic acid they produced the same effect with another reducing agent, dimercaptopropanol (BAL). This explanation has been accepted by others (56), although the oxidation state of copper for maximum intestinal absorption has not been established. An intramucosal competition of ascorbic acid for sulfhydryl sites on metallo-thioneins was demonstrated (57). If this ligand has any regulatory role in copper uptake, this alternative mechanism of ascorbic acid-copper interaction could explain the mechanism. Experimental confirmation of an ascorbic-acid-induced inhibition of copper absorption in the human intestine has not been presented. 

Syrup of ipecac (purging solution) and gastric lavage should be administered within 4-6 h of oral exposure to arsenic. Antidotes include 3-5 mg kg BAL (2,3-dimercaptopropanol) administered intramuscularly. Penicilamine has also been administered with optical neuritis as a side effect. Certain synthetic, water-soluble dimercapto compounds (DMSA - meso-2, 3-dimercaptosuccinic acid and 2,3-dimercaptopro-pane-l-sulfonate) have been found effective. 

For acute toxicity, emesis is recommended. Treatment is symptomatic. A combination of BAL (British AntiLewisite 2,3-dimercaptopropanol) and calcium-ethylene diamine tetraacetic acid has been used successfully in a poisoned infant. Penicillamine has also been used. Recently, oral administration of 2,3-dime-rcaptol-propane sulfonate was found to be effective in experimental rodents. Electrolyte balance must be maintained when gastric lavage is indicated. Potassium ferrocyanide should be added to precipitate the copper. 

The toxic effects of arsenic can be counteracted with (1) saline purgatives, (2) various demulcents that coat irritated gastrointestinal mucous membranes, (3) sodium thiosulfate, and (4) mono- and dithiol-containing compounds and 2,3-dimercaptopropanol. Arsenic uptake in rabbit intestine is inhibited by phosphate, casein, and various metal-chelating agents. Mice and rabbits are significantly protected against sodium arsenite intoxication by A-(2,3-dimercaptopropyl)phthalamidic acid. Conversely, the toxic effects of arsenite are potentiated by excess dithiols, cadmium, and lead, as evidenced by reduced food efficiency and disrupted blood chemistry in rodents. 

Inhibitory effect on intestinal vitamin K synthesis, VI, 41 7,12-DiketochoIanic acid, configuration, VIII, 261 Dimenformon, see Estradiol benzoate 2,3-Dimercaptopropanol (BAL), as antidote against lewisite, VII, 106 mercury, VII, 106 mustard gas, VII, 106... 

As might be expected, the inhibition of kininase activity results in the enhancement and prolongation of kinin effects. This can be achieved with various agents. e.g. cystein. dimercaptopropanol (BAL). Ca-EDTA. e-aminocaproic acid. etc. Most of them are effective chelating agents and also block metalloenzymes such as alcohol dehydrogenase. However, the inhibition of kininase does not satisfactorily explain all the reported potentiations of kinin action... 

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