Bidrin (3-Hydroxy-N,N-dimethylcrotonamide dimethyl phosphate) 
SD 9129 (3-Hydroxy-N-methylcrotonamide dimethylphosphate) (N-methyl bidrin) 
Using p>*-labeled bidrin and rats, 83% of the recovered activity after 
injection was in the form of dimethylphosphate after 20 hours. Metabolites 
were excreted rapidly. Within 24 hours, 83% of the injected dose had been 
excreted. Extensive oxidation occurred with the formation of hydroxymethyl 
bidrin and N-methyl bidrin. Subsequent hydrolysis gave rise to dimethyl- 
phosphate, bidrin acid, desmethyl bidrin acid, monomethylphosphate, and 
finally inorganic phosphate. Hydrolysis of bidrin itself gave rise to des- 
methyl bidrin (Bull and Lindquist, 1964). 
When administered orally to rats, 63-71% of the p32 was excreted in 
48 hours. No marked sex or compound differences were noted. Most of the 
radioactivity was excreted in urine within 6 hours. An additional 5-67 
appeared in the feces within 48 hours following treatment. Residual p32 
in the tissues did not vary with sex. An additional 12% was recovered as 
clo, within 48 hours after treatment of male rats with bidrin-N-methy1-c!4 
(Menzer, 1965; Menzer and Casida, 1965). 
Significant amounts of N-hydroxymethylamide analog of SD 9129 appeared 
following administration of either bidrin or SD 9129 while the N-methyl-N- 
hydroxymethylamide compound was present only following bidrin treatment, 
and the unsubstituted amide only following SD 9129 treatment (Menzer and 
Casida, 1965). 
Goats treated orally with bidrin or SD 9129 excreted in the urine a 
high proportion of the administered p32 or N-methy1-cl4 labels. Trace 
amounts of bidrin, SD 9129, the N-hydroxymethylamide analog of SD 9129, 
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