Effects of Diet on PCB-Induced Changes in Xenobiotic Metabolism in the Liver of Channel Catfish (Ictalurus punctatus)

1988 ◽  
Vol 45 (1) ◽  
pp. 132-137 ◽  
Author(s):  
Gerald T. Ankley ◽  
Vicki S. Blazer

Effects of nutrition on xenobiotic-metabolizing enzymes in fishes are not well known. We fed three groups of channel catfish (Ictalurus punctatus) either a synthetic, laboratory-prepared diet or one of two commercial catfish rations. After 3 mo on each diet, fish were treated with the enzyme inducer Aroclor 1254. Hepatic microsomal monooxygenase (MO) activity was lower in untreated fish fed a commercial diet than in those fed the laboratory diet. Aroclor 1254 increased MO activity to a lesser degree in fish fed that same commercial diet compared with those receiving the laboratory or other commercial diet. Hepatic microsomal UDP-glucuronosyltransferase (UDPGT) activity was similar in all control fish; however, Aroclor 1254 increased UDPGT activity to differing degrees in the three diet groups. Hepatic cytosolic glutathione S-transferase (GST) activity was increased by Aroclor 1254 to a similar extent in all diet groups; however, levels of GST activity generally were higher in fish fed the commercial diets than in those fed the laboratory ration. These data indicate that diet can affect the toxicity of xenobiotics to fishes through alterations in hepatic enzyme systems, and thus should be considered a potential source of variation in toxicological studies with fishes.

1976 ◽  
Vol 33 (6) ◽  
pp. 1343-1352 ◽  
Author(s):  
L. G. Hansen ◽  
W. B. Wiekhorst ◽  
J. Simon

Channel catfish (Ictalurus punctatus) fingerlings fed a diet containing 20 ppm Aroclor® 1242 for 20 wk responded with a reduced weight gain and liver hypertrophy when compared to controls. When treated fish were fed the control diet for 8 subsequent wk followed by 8 additional wk of Aroclor® feed, they approached control values for liver weight and surpassed the rate of gain for control fish. No histopathological lesions were observed in the fish fed PCB. The total PCB in fish declined slightly during an 8-wk PCB-free period beginning at week 12, but the PCB burden remained constant when the PCB-free period was begun at week 20. During PCB-free periods, there was a shift in residues from the edible carcass to the offal. Residues are discussed as components as well as total PCB. We found that a tetrachlorobiphenyl is more persistent than some higher chlorinated components and that various tissues accumulated different profiles of components.


2002 ◽  
Vol 9 (1) ◽  
pp. 176-181 ◽  
Author(s):  
Xuting Wang ◽  
Harry W. Dickerson

ABSTRACT Channel catfish (Ictalurus punctatus) that survive infection with the parasitic ciliate Ichthyophthirius multifiliis acquire immunity to subsequent challenge and produce specific antibodies in serum that immobilize the parasite in vitro. Cellular surface protein antigens targeted by these antibodies are referred to as immobilization antigens (i-antigens). By using an immobilizing mouse monoclonal antibody as a ligand, the i-antigen of I. multifiliis isolate G5 was purified to homogeneity by immunoaffinity chromatography, and its immunogenicity was confirmed by inoculating rabbit and channel catfish to produce immobilizing antisera. To test the purified i-antigen as a subunit vaccine, channel catfish fingerlings were injected intraperitoneally (i.p.) with purified i-antigen at a dose of 10 μg/fish in complete Freund’s adjuvant on day 1, followed by a second i.p. injection of the same amount of i-antigen in incomplete Freund’s adjuvant on day 15. Negative control fish were immunized similarly with either bovine serum albumin (BSA) or an immobilization-irrelevant I. multifiliis protein. On day 84, the fish were challenged with live I. multifiliis G5 theronts at a dose of 15,000 cells per fish. Seventy-two percent of the fish immunized with i-antigen survived the challenge. All negative control fish died within 16 days of exposure. There was a significant difference in the median days to death between the negative control fish injected with BSA and the fish that died following vaccination with i-antigen. Fish injected with i-antigen developed high immobilizing antibody titers in serum. This is the first demonstration of a direct role for i-antigens in the elicitation of protective immunity, suggesting that these proteins by themselves serve as effective subunit vaccines against I. multifiliis.


1975 ◽  
Vol 32 (11) ◽  
pp. 2197-2204 ◽  
Author(s):  
Ray L. Argyle ◽  
George C. Williams ◽  
Clara B. Daniel

Fingerling channel catfish (Ictalurus punctatus) were given diets containing 0, 0.4, 0.8, or 4.0 μg dieldrin/g of food (dry weight) for 210 days, followed by a dieldrin-free diet for 56 days. Catfish receiving 4.0 μg dieldrin/g of food gained about 17% less weight than the control fish in 210 days and about 35% less weight during the last 126 days of the 210-day period. No growth differences were attributable to the ingestion of 0.4 or 0.8 μg dieldrin/g of feed. Mortality during the experiment was random and not appreciable.Dieldrin accumulations were characterized by an immediate rapid rise of residue levels in the tissues, followed by a period during which concentrations were relatively stable. Residues in tissues decreased rapidly after dieldrin was withdrawn from the diet. Dieldrin half-life was 9.6 days (mean for the three groups).Theoretical residue concentrations calculated from the growth, feeding, and half-life data were similar to the empirical concentrations, although the theoretical values were consistently the higher. The recoverable concentration accounted for 25.7% (mean of the three treatments) of the theoretical concentration.


2003 ◽  
Vol 60 (4) ◽  
pp. 415-420 ◽  
Author(s):  
Natasa Strelic ◽  
Zorica Saicic ◽  
Zvonko Magic ◽  
Mihajlo Spasic ◽  
Natasa Trutic ◽  
...  

Background. The influence of low doses of aflatoxin B1 (AFB1) and partial hepatectomy (PH) on glutathione-S-transferase (GST) activity was studied in the plasma and liver of the rat. Methods. The animals were divided into four groups. The first (I) and the second (II) group were treated with AFB1 freshly dissolved in dimethyl sulphoxide (DMSO), and administered as a single intraperitoneal dose of 50 mg/rat 24 hrs after the rats had undergone either sham operation or, 40% PH, respectively. The third group (III) of animals was treated with a total dose of 1 mg AFB1 - 5 days per week during a period of 8 weeks. The non-treated animals were used as controls (C). Results. We observed a significant increase of GST activity in the plasma of all experimental groups compared to the controls (C), (p<0.02 to p<0.005). In the liver, the GST activity of all experimental groups was also significantly increased, compared to the controls (from p<0.02 to p<0.005). Conclusion. The administration of both single and multiple doses of AFB1 led to long term increase of GST activity in the rat plasma and liver, and partial hepatectomy had no significant effect on this phenomenon.


1990 ◽  
Vol 270 (2) ◽  
pp. 483-489 ◽  
Author(s):  
J A Johnson ◽  
T L Neal ◽  
J H Collins ◽  
F L Siegel

Glutathione S-transferase (GST) subunits in rat liver cytosol were separated by reverse-phase h.p.l.c.; five major proteins were isolated and identified as subunits 1, 2, 3, 4 and 8. F.p.l.c. chromatofocusing resolved the affinity-purified GST pool into nine different isoenzymes. The five basic (Alpha class) dimeric peaks of GST activity were 1-1, 1-2a, 1-2b, 2-2a and 2-2b. Reverse-phase h.p.l.c. analysis revealed that subunit 8 was also present in the protein peaks designated 1-1, 1-2a and 1-2b. The four neutral (Mu class) isoenzymes were 3-3, 3-4, 3-6 and 4-4. The GST pool was methylated in vitro before reverse-phase h.p.l.c. or f.p.l.c. chromatofocusing. Chromatofocusing indicated that the Mu class isoforms (3-3, 3-4 and 4-4) were the primary GSTs methylated, and h.p.l.c. analysis confirmed that subunits 3 and 4 were the major methyl-accepting GST subunits. The addition of calmodulin stimulated the methylation in vitro of GST isoenzymes 3-3, 3-4 and 4-4 by 3.0-, 7.5- and 9.9-fold respectively. Reverse-phase h.p.l.c. also indicated that only the methylation of GST subunits 3 and 4 was stimulated by calmodulin. Basic GST isoenzymes were minimally methylated and the methylation was not enhanced by calmodulin. Investigation of the time course of methylation of GST subunits 3 and 4 indicated that at incubation times less than 4 h the methylation of both Mu class subunits was stimulated by calmodulin, and that under such conditions subunit 4 was the preferred substrate. In contrast, there was essentially no calmodulin-stimulated methylation at incubation times of 4 or 6 h, and the methylation of subunit 3 was predominant. Kinetic parameters at 2 h of incubation were determined in the presence and in the absence of calmodulin. The addition of calmodulin doubled the Vmax. for methylation of both subunits 3 and 4 and decreased the Km of subunit 4 for S-adenosyl-L-methionine 3.6-fold. Finally, methylation was substoichiometric and after 6 h of incubation ranged from 2.8 to 7.6% on a mole-to-mole basis for subunits 4 and 3 respectively.


2001 ◽  
Vol 43 (2) ◽  
pp. 155-160 ◽  
Author(s):  
L. Xu ◽  
J. Chen ◽  
Y. Zhang ◽  
C. C. Cheung ◽  
P. K. Lam

Gold-lined sea bream (Rhabdosargus sarba) were intraperitoneally injected with 35 mg/kg benzo[a]pyrene (in DMSO), with fish administered DMSO as the solvent control. Fish were sacrificed 3 days post injection and their livers dissected for the analysis of adenosine triphosphates (ATPase), glutathione-S-transferase (GST), DNA adducts and ethyoxyresorufin-O-deethylase (EROD). Exposure to B[a]P resulted in reduced ATPase activity, elevated GST activity and DNA adduct level, but no apparent change in EROD activity.


2012 ◽  
Vol 36 (2) ◽  
pp. 314
Author(s):  
Jian-feng LU ◽  
Chang-wei MENG ◽  
Jin LI ◽  
Zi-hui GONG ◽  
Lin LIN ◽  
...  

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