DDVP (Vapona) (2,2-dichlorovinyl dimethyl phosphate) 
Using whole homogenates of rat and rabbit tissues, the course of 
metabolism of DDVP-P24 was followed. In liver, kidney, spleen, and adrenal 
glands, the principal metabolite was dimethyl phosphate (50-85%). The 
remainder appeared as O-methyl 2,2-dichlorovinyl phosphate, monomethyl 
phosphate, and inorganic phosphate. In plasma, 98-100% of the DDVP 
hydrolyzed was accounted for as dimethyl phosphate. When dimethyl phosphate- 
p?? was incubated with liver homogenates or plasma, all radioactivity was 
recovered as unchanged dimethyl phosphate. In the presence of a rat liver 
soluble preparation, DDVP was degraded to dichloroacetaldehyde and some 
dichloroacetic acid. The aldehyde was reduced to the corresponding 
alcohol which was excreted as the glucuronide. Similar results were obtain- 
ed with a rat, cow, and goat following oral or intraperitoneal administration 
(Casida et al., 1962; Hodgson and Casida, 1962). 
Studies with houseflies have shown that dipterex is converted to DDVP 
which in turn is degraded to dimethyl phosphate and dichloroacetaldehyde 
(Metcalf et al., 1959). 
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