Decreased responsiveness of the hepatic cytochrome P450 1A1 system in rainbow trout (Oncorhynchus mykiss) after prolonged exposure to PCB

1995 ◽  
Vol 33 (2) ◽  
pp. 141-153 ◽  
Author(s):  
Malin Celander ◽  
Lars Förlin
1997 ◽  
Vol 37 (2-3) ◽  
pp. 237-251 ◽  
Author(s):  
Jun-Lan Wang Buhler ◽  
Xine Zhao ◽  
Yea-Huey Yang ◽  
Cristobal L. Miranda ◽  
Donald R. Buhler

1996 ◽  
Vol 69 (6) ◽  
pp. 1419-1441 ◽  
Author(s):  
S. F. Perry ◽  
S. G. Reid ◽  
E. Wankiewicz ◽  
V. Iyer ◽  
K. M. Gilmour

1998 ◽  
Vol 157 (1) ◽  
pp. 63-70 ◽  
Author(s):  
JM Wilson ◽  
MM Vijayan ◽  
CJ Kennedy ◽  
GK Iwama ◽  
TW Moon

We report for the first time that beta-naphthoflavone (BNF) abolishes ACTH stimulation of cortisol production in rainbow trout (Oncorhynchus mykiss). There was significantly higher hepatic cytochrome P450 content and ethoxyresorufin O-de-ethylase and uridine-5'-diphosphoglucuronic acid transferase activities in BNF-treated fish than in sham-treated controls. BNF did not significantly affect either plasma turnover or tissue distribution of [3H]cortisol-derived radioactivity. Hepatic membrane fluidity and hepatocyte capacity for cortisol uptake were not altered by BNF as compared with the sham-treated fish. These results taken together suggest that BNF does not affect cortisol-clearance mechanisms in trout. A 3 min handling disturbance period elicited a plasma cortisol response in the sham-treated fish; however, the response in the BNF-treated fish was muted and significantly lower than in the sham fish. This in vivo response corroborates the lack of interrenal sensitivity to ACTH in vitro in the BNF-treated fish, suggesting that BNF affects the ACTH pathway in trout. Our results suggest the possibility that cytochrome P450-inducing compounds may affect cortisol dynamics by decreasing interrenal responsiveness to ACTH stimulation in fish, thereby impairing the physiological responses that are necessary for the animal to cope with the stressor.


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