Characteristics of the Uptake of 3,5,3′-Triiodo-l-thyronine andl-Thyroxine into Red Blood Cells of Rainbow Trout (Oncorhynchus mykiss)

1996 ◽  
Vol 103 (2) ◽  
pp. 200-208 ◽  
Author(s):  
J.M. McLeese ◽  
J.G. Eales
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.


2018 ◽  
Vol 16 (4) ◽  
pp. 292-299
Author(s):  
K. Georgieva ◽  
G. Zhelyazkov

The present research aimed to examine the effect of dietary phytoextracts supplementation on the growth performance, haematological (white blood cells, red blood cells, hemoglobin, hematocrit) and biochemical (glucose, urea, creatinine, total protein, albumin, ASAT, ALAT) blood parameters of rainbow trout (Oncorhynchus mykiss W.), cultivated in a recirculation system. The fish were divided into 6 groups: one control (C) and five experimental groups in whose food was added phytoextracts of curcumin (EC), paprika (EP), thyme (ET), oregano (EO) and garlic (EG). The inclusion of phytoextracts had no significant effect on growth parameters of fish from EC, EP, ET, EO and EG groups (P>0.05). Statistically significantly lower feed consumption per unit weight gain was observed in EO group vs C (Р<0.05). The phytoextract supplementation had significant influence on some of the haematological (white blood cells, red blood cells, hemoglobin) and biochemical (urea, creatinine, total protein, albumin, ASAT, ALAT) blood parameters of rainbow trout.


2000 ◽  
Vol 203 (6) ◽  
pp. 1039-1045 ◽  
Author(s):  
M.C. Phillips ◽  
C.D. Moyes ◽  
B.L. Tufts

The effects of cell age on metabolism in the nucleated red blood cells of rainbow trout (Oncorhynchus mykiss) were examined. Red blood cells were separated according to age using fixed-angle centrifugation. The mean erythrocyte haemoglobin concentration in old red blood cells was found to be 120 % of that in young red blood cells. In young red blood cells, the activities of the mitochondrial enzymes citrate synthase and cytochrome oxidase were 135–200 %, respectively, of those measured in old red blood cells. The activity of the glycolytic enzyme lactate dehydrogenase in young red blood cells was 170 % of that in old red blood cells, whereas the activity of the glycolytic enzyme pyruvate kinase was not significantly affected by cell age. In addition, young red blood cells consumed over twice as much O(2) and devoted 50 % more O(2) to protein synthesis and the activity of Na(+)/K(+)-ATPase than old red blood cells. Red blood cell age did not significantly affect the rate of lactate production. This study shows that ageing in rainbow trout nucleated red blood cells is accompanied by a significant decline in aerobic energy production and the processes it supports, as well as a corresponding increase in the glycolytic contribution to metabolism.


2000 ◽  
Vol 203 (6) ◽  
pp. 1047-1058 ◽  
Author(s):  
S. Volkel ◽  
M. Berenbrink

A method for the quantitative determination of sulphaemoglobin (SHb) in a mixture of haemoglobin derivatives by spectral deconvolution is described. SHb formation was studied in haemolysates and in red blood cells of the sulphide-sensitive rainbow trout (Oncorhynchus mykiss) and of the sulphide-tolerant common carp (Cyprinus carpio). Addition of sulphide caused the formation of SHb in haemolysates of both animals. However, haemoglobin from common carp was much less sensitive to sulphide than was trout haemoglobin. The maximal obtainable SHb fraction was approximately 30 % in trout and 10 % in carp haemolysates. In both animals, the SHb fraction increased with increasing Hb and sulphide concentrations up to 100 micromol l(−)(1) and 1 mmol l(−)(1), respectively, and was favoured by a low pH. An increase of temperature between 5 and 25 degrees C strongly increased SHb formation in trout haemolysate. In contrast, temperature changes had almost no effect on SHb production in carp. Within trout red blood cells, approximately 7 % of total haemoglobin was converted to SHb during 60 min of incubation (with 2.5 mmol l(−)(1) sulphide), inducing a 20 % loss of haemoglobin oxygen-saturation. In carp red blood cells incubated under identical conditions, SHb formation was minimal and haemoglobin oxygen-saturation was not affected.


1998 ◽  
Vol 76 (7) ◽  
pp. 1325-1328 ◽  
Author(s):  
J M McLeese ◽  
J G Eales

We exposed rainbow trout, Oncorhynchus mykiss, to various environmental conditions known to alter thyroid function in order to determine their effects on the in vitro carrier-mediated transport rate (J) of 3,5,3prime-triiodo-L-thyronine (T3) into red blood cells (RBC). Values for J (fmol T3 transported/(106 cells · min)) were (i) increased by assay temperature from 0 to 12°C but not from 12 to 21°C, (ii) unaltered by acclimation for 14 d at 5 or 12°C, (iii) depressed by a restricted food ration (0.5% of mean body mass/d) but unaltered by 14 d of fasting, (iv) depressed by a T3 challenge created by feeding T3-supplemented food (12 ppm T3) for 14 d, and (v) depressed 10 d after transport to our laboratory. We conclude that certain conditions that alter thyroid function also alter the rate of T3 transport into trout RBC, with possible consequences for exchange of T3 between plasma and RBC.


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