Interactions among Antioxidant Defenses in Liver of Rainbow Trout (Oncorhynchus mykiss) Exposed to Cadmium

1993 ◽  
Vol 50 (1) ◽  
pp. 156-162 ◽  
Author(s):  
V. P. Palace ◽  
H. S. Majewski ◽  
J. F. Klaverkamp

Rainbow trout (Oncorhynchus mykiss) (mean weight 180 ± 10 g) fed diets deficient in ascorbic acid, tocopherol, both, or neither were exposed to one of three cadmium concentrations (0, 2, or 4 μg Cd/L). After 181 d of exposure, liver and whole blood were sampled. Cadmium exposure was found to significantly increase the Cd content in liver, especially in fish fed a diet deficient in ascorbic acid. Hepatic stores of ascorbic acid decreased in fish exposed to Cd and in fish fed diets deficient in tocopherol and ascorbic acid. Depletion of tocopherol in liver occurred only in those fish fed a diet deficient in tocopherol and exposed to Cd. Superoxide dismutase activity in liver increased with Cd exposure and with dietary deficiencies of tocopherol and ascorbic acid, while catalase was inhibited by exposure to Cd alone. Glutathione peroxidase activity was unaffected by Cd but was lower in fish fed a diet deficient in both tocopherol and ascorbic acid. Erythrocyte fragility, measured by spontaneous hemolysis of red blood cells in physiological saline, was increased by Cd exposure and the deficiencies of dietary tocopherol and ascorbic acid.

1990 ◽  
Vol 47 (8) ◽  
pp. 1518-1525 ◽  
Author(s):  
Konrad Dabrowski ◽  
Reinhard Lackner ◽  
Cristine Doblander

The concentrations of ascorbic acid in several tissues of rainbow trout (Oncorhynchus mykiss) are significantly influenced by various dietary treatments. Ascorbic acid was taken up readily by erythrocytes, kidney, liver, intestine, spleen, and brain in fish fed an ascorbate supplemented diet (AA group), the concentration being from 1.5 to 14.8-fold higher than in fish fed a diet lacking ascorbate (control group). In fish fed a diet supplemented with an equimolar amount of ascorbic acid in the form of ascorbic sulfate (AS group) the ascorbic acid concentrations in kidney, intestine, and erythrocytes were significantly elevated above those of the control group. Ascorbic sulfate was found in kidney, liver, and intestine of the AS group, but not in other groups. In fish fed a diet devoid of vitamin C the ascorbic acid concentrations in kidney, liver, intestine, and spleen were signficantly lower than in fasting fish over the same period of time (28 d), suggesting a high demand for vitamin C in an actively feeding animal. Salmonid fish are therefore probably unable to utilize ascorbic sulfate sufficiently to prevent the appearance of vitamin C deficiency, and thus resemble scurvy-prone mammals in this respect.


Aquaculture ◽  
1999 ◽  
Vol 180 (1-2) ◽  
pp. 79-87 ◽  
Author(s):  
J.H Blom ◽  
K Dabrowski ◽  
J.D Rapp ◽  
Y Sakakura ◽  
K Tsukamoto

1997 ◽  
Vol 200 (3) ◽  
pp. 607-614 ◽  
Author(s):  
S Currie ◽  
B Tufts

Unlike enucleated mammalian red blood cells (rbcs), the nucleated rbcs of lower vertebrates are capable of protein synthesis and may, therefore, serve as a valuable model to investigate the adaptive significance of stress protein synthesis in cells. This study examined the synthesis of stress protein 70 (Hsp70) in rbcs of the temperature-sensitive rainbow trout Oncorhynchus mykiss in response to heat shock and anoxia. Through western blot analysis, we have demonstrated that rainbow trout rbcs synthesize Hsp70 both constitutively and in response to an increase in temperature. Radioisotopic labelling experiments indicated that the temperature at which Hsp70 synthesis was induced in fish acclimated to 10 °C was between 20 and 25 °C. Actinomycin D blocked de novo Hsp70 synthesis, implying that synthesis of Hsp70 is regulated at the level of transcription in rainbow trout rbcs. Since trout rbcs rely heavily on aerobic metabolism, but may also experience very low oxygen levels within the circulation, we also examined the relative importance of (1) anoxia as a stimulus for Hsp70 synthesis and (2) oxygen as a requirement for protein synthesis under control and heat-shock conditions. We found that trout rbcs were capable of protein synthesis during 2 h of anoxia, but did not increase Hsp70 synthesis. Moreover, rbcs subjected to combined anoxia and heat shock exhibited increases in Hsp70 synthesis that were similar in magnitude to those in cells exposed to heat shock alone. The latter results suggest that rainbow trout rbcs are (1) able to synthesize non-stress proteins during anoxia, (2) capable of tolerating periods of reduced oxygen availability without increased synthesis of stress proteins and (3) able to maintain the integrity of their heat-shock response even during periods of anoxia.


2019 ◽  
Vol 25 (6) ◽  
pp. 1345-1353
Author(s):  
Jun‐Ming Deng ◽  
Xin‐Dang Zhang ◽  
Jian‐Wei Zhang ◽  
Bao‐Liang Bi ◽  
Heng‐Zhi Wang ◽  
...  

1989 ◽  
Vol 46 (11) ◽  
pp. 1952-1957 ◽  
Author(s):  
K. Dabrowski ◽  
G. Köck

The sites of absorption of ascorbic acid (AA) in the rainbow trout (Oncorhynchus mykiss) gut were located in the stomach (20.7%), pyloric caecae region (23.4%), middle intestine (21.9%) and posterior intestine (20.1%). Ascorbic sulfate (AS) were found to be absorbed in the stomach (27.7%) although it is likely that the figure obtained is an overestimate. This conclusion is based on the concentration factor of the intestinal contents (faeces/food ratio) being much higher for ascorbic sulfate than for an external dietary marker, chromic oxide. The apparent protein absorption rates from the three diets used were not significantly different (P < 0.01), ranging from 86.9 to 91.5%. Three subsequent samplings, one week apart, did not reveal changes in AA or AS absorption in trout, suggesting that fish were neither "saturated" with AA nor had they developed the means to utilize the dietary AS. In most cases, the mineral contents in faeces were similar for all diets, although the concentration factors (faeces/food level), varied greatly during the course of the trial (1.9–7.1 for Zn, 1.8–4.9 for Fe, and 2.4–3.7 for Cu). The concentrations of Fe and Zn in the contents of the posterior intestine were lower in the fish fed an AA-supplemented diet than in fish fed on AS and deficient diets, which may suggest an increased absorption of these elements.


Parasitology ◽  
1997 ◽  
Vol 114 (4) ◽  
pp. 375-382 ◽  
Author(s):  
X. ZUO ◽  
P. T. K. WOO

Natural anti-proteases (α1-protease inhibitor (α1-PI; α1-antitrypsin) and α2-macroglobulin (α2-M)) were found in the blood of rainbow trout, Oncorhynchus mykiss and brook charr, Salvelinus fontinalis. The α2-M inhibited Cryptobia salmositica proteases and was significantly higher in brook charr than in rainbow trout. Under in vitro conditions it took longer for the same number of parasites to neutralize the α2-M in charr than in trout blood. The haemolysis which occurred when C. salmositica was incubated in the blood of rainbow trout was due to neutralization of α2-M. This in vitro study also showed that it was the metalloprotease of C. salmositica that lysed red blood cells and the plasma of the two species of fishes initially prevented haemolysis by inhibiting the proteolytic activity. We suggest that the natural plasma α2-M plays an important role in defence against cryptobiosis in fishes.


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