Fluoride spleen

Perchloryl fluoride is white as a solid and colorless as a liquid and gas. It possesses a characteristic sweetish odor 92). Its toxicity is moderate and comparable to that of CH2OHCN or Clg. Tests on mice showed an acute vapor toxicity (LD50) of 630 ppm at 4-hr exposure time. Exposure of monkeys to 40 ppm FClOs in air for 3 months resulted in enlarged spleens and lungs together with some evidence of red cell destruction 222). 

Milk acid phosphatase has been purified to homogeneity by various forms of chromaotgraphy, including affinity chromatography purification up to 40 000-fold has been claimed. The enzyme shows broad specificity on phosphate esters, including the phosphoseryl residues of casein. It has a molecular mass of about 42 kDa and an isoelectric point of 7.9. Many forms of inorganic phosphate are competitive inhibitors, while fluoride is a powerful non-competitive inhibitor. The enzyme is a glycoprotein and its amino acid composition is known. Milk acid phosphatase shows some similarity to the phosphoprotein phosphatase of spleen but differs from it in a number of characteristics. 

Sodium fluoride did not induce reverse mutations in Salmonella typhimurium, nor did it induce gene conversion in Saccharomyces cerevisiae. A fluoride level of 0.4-1.0mgl inhibited DNA repair after irradiation of mouse spleen cells in vitro. Sodium fluoride was not mutagenic in cell cultures of human leukocytes at concentrations of 18 and 54mgl . Little or no effect was noted on chromosomes when mouse oocytes were exposed in vitro to a fluoride concentration of 200 mg 1 in media for up to 14 h. 

In addition to activation by heparin, lipoprotein lipase requires the addition of cations and of a fatty acid acceptor such as serum albiunin (254). The enzyme is inhibited by high concentrations of NaCl (M), 5% sodium taurocholate and 5% protamine (376, 393), sodium fluoride and diethyl p-nitrophenyl phosphate (394), and polyamino acids (395). Particle-free extracts of human or rabbit spleen, kidney, and liver are also stated to be inhibitory (396). 

Pinkse MWH, Merkx M, Averill BA. 1999. Fluoride inhibition of bovine spleen purple acid phosphatase characterization of a ternary enzyme-phosphate-fluoride complex as a model for the active enzyme-substrate-hydroxide complex. Biochemistry 38 9926-9936. 

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