Em. Zou et M. Fingerman, Effects of estrogenic agents on chitobiase activity in the epidermis and hepatopancreas of the fiddler crab, Uca pugilator, ECOTOX ENV, 42(2), 1999, pp. 185-190
The effects of exposure of the fiddler crab, Uca pugilator, to the estrogen
ic xenobiotics Aroclor 1242, diethylstilbestrol (DES), endosulfan, and 4-oc
tylphenol on chitobiase activity in the epidermis and hepatopancreas were i
nvestigated. Endosulfan at 0.05 and 0.20 mg/liter significantly inhibited c
hitobiase in the epidermal and hepatopancreatic tissues of U. pugilator exp
osed for 3 days. After a 7-day exposure there was a significant decrease in
epidermal chitobiase activity in the animals exposed to Aroclor 1242 at 8.
0 mg/Iiter, DES at 5.0 mg/liter, and endosulfan at 0.05 and 0.20 mg/liter,
while Aroclor 1242 at 2.0 and 8.0 mg/liter and endosulfan at 0.05 and 0.20
mg/liter significantly inhibited chitobiase activity in the hepatopancreas.
4-Octylphenol at 2.0 and 10.0 mg/liter had no significant effect on epider
mal chitobiase activity, while 7 days of exposure to 10.0mg/liter 4-octylph
enol significantly inhibited hepatopan-creatic chitobiase activity. Because
chitobiase is necessary for the partial digestion of the chitinous exoskel
eton as part of the molting process, inhibition of this enzyme by these est
rogenic agents can account for at least some of the slowing of molting that
occurs when crustaceans are exposed to these agents. Possible mechanisms r
egarding the decline of chitobiase activity in the presence of estrogenic a
gents are presented. (C) 1999 Academic Press.