lung> erythrocytes> plasma =0. In English sparrows and chickens, activity 
in kidney exceeded that in liver (669). 
The rate of degradation of parathion by rat and human liver was low 
(944). When rat liver microsomes metabolized parathion, the major metab- 
olites identified were: desethyl paraoxon, paraoxon, diethyl phosphate, 
diethyl phosphorothionate and p-nitrophenol. Similar results were obtained 
with guinea pigs and rabbits (899, 1068, 1076, 1077, 1239, 1630). When 
methyl parathion was used, the desmethyl analog was observed (499). 
During studies of the inhibition of trypsin and chymotrypsin, p- 
nitrophenol was released (624, 791). This material was capable of forming 
a complex with glutamic acid in the myosin molecule (844). 
Parathion-S-> was applied to a cranberry bog. Flooding was done 24 
hours after application. One liter of the water was added to an aquarium 
containing fresh water mussels (Elliptio companatus Solander) and estu- 
arine fish (Fundulus heteroclitus L.). Three metabolites were detected in 
the fish. One was identified as aminoparathion. However, it was possible 
that the aminoparathion was formed by microorganisms rather than by the 
metabolism of the fish (1006). 
Activation and degradation of methylparathion by liver microsomes of 
chickens, muscovey ducks, albino rats, mice guinea pigs, sheep, cattle, 
and hogs was studied. Percent activation of methyl parathion (see table II) 
was calculated from the following formula (737). 
Tey directly assay P(0) analogue 
Ploy ~ Ico incubated insecticide 
X 10 
After incubation of methyl, ethyl, propyl or isopropyl parathion 
with microsomes from houseflies, rat liver or rabbit liver, the corresponding 
phenol was found in each case. Each compound was also converted to its 
corresponding oxon analog. Some conversion of the oxons to phenols also 
occurred. These reactions occurred only in the presence of NADPH, + 0, 
(1700). 
265 
