scholarly journals Interaction of cadmium and oestradiol-17β on metallothionein and vitellogenin synthesis in rainbow trout (Oncorhynchus mykiss)

1995 ◽  
Vol 307 (1) ◽  
pp. 197-203 ◽  
Author(s):  
P E Olsson ◽  
P Kling ◽  
C Petterson ◽  
C Silversand
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Intraperitoneal Injection ◽  
High Molecular Mass ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Vitellogenin Synthesis ◽  
Liver Somatic Index ◽  
Somatic Index ◽  
Rainbow Trout Liver ◽  
Vitellogenin Mrna

The induction of metallothionein and vitellogenin synthesis in rainbow trout liver was studied after injection of oestradiol-17 beta alone or in combination with cadmium or zinc. Intraperitoneal injection of oestradiol-17 beta increased the liver somatic index, with subsequent induction of vitellogenin synthesis. Oestradiol-17 beta did not induce metallothionein synthesis. Injection of cadmium induced the synthesis of metallothionein mRNA and metallothionein. Injection of oestradiol-17 beta in combination with cadmium resulted in inhibition of transcription and translation of both vitellogenin and metallothionein. Chromatography of liver cytosols revealed that cadmium, when co-injected with oestradiol-17 beta, did not bind to metallothionein but would initially bind to high-molecular-mass (HMr) cytosolic proteins. In fish injected with cadmium in combination with oestradiol-17 beta, cadmium was gradually redistributed from HMr proteins to metallothionein. This resulted in induction of metallothionein synthesis and in binding of most of the cadmium to metallothionein. Induction of vitellogenin mRNA was observed 15 days after injection, as cadmium was being redistributed to newly synthesized metallothionein. These findings indicate that cadmium inhibits the transcription of vitellogenin. The binding of cadmium to these non-metallothionein proteins represses the induction of metallothionein and results in increased toxicity of the metal. Preinduction of metallothionein by zinc injections resulted in decreased cadmium sensitivity of the fish and a decrease in the repression of vitellogenin mRNA. Furthermore, a role for metallothionein in the detoxification of cadmium is indicated by the induction of vitellogenin synthesis that occurs once metallothionein has begun sequestering cadmium.

scholarly journals A role of metallothionein in zinc regulation after oestradiol induction of vitellogenin synthesis in rainbow trout, Salmo gairdneri

1989 ◽  
Vol 257 (2) ◽  
pp. 555-559 ◽  
Author(s):  
P E Olsson ◽  
M Zafarullah ◽  
L Gedamu
Keyword(s):  
Rainbow Trout ◽  
Experimental Period ◽  
Differential Pulse ◽  
Salmo Gairdneri ◽  
Differential Pulse Polarography ◽  
Pulse Polarography ◽  
Vitellogenin Synthesis ◽  
Zinc Concentrations ◽  
Liver Somatic Index ◽  
Vitellogenin Mrna

The regulation of metallothionein (MT) biosynthesis in rainbow-trout liver was studied after a single intraperitoneal injection of oestradiol-17 beta. Sampling was performed after 2, 7, 14, 21, 28 and 35 days. Following induction of vitellogenin synthesis in the liver, liver somatic index (LSI) rose from 1.25 to 2.00 in 14 days. Associated with the increase in LSI was an elevation of hepatic vitellogenin mRNA and zinc concentrations. The vitellogenin mRNA concentrations peaked at 7 days after treatment. The zinc concentrations increased to a peak at day 14. MT was analysed by using differential pulse polarography and a rainbow-trout MT RNA probe. The MT mRNA concentrations rose after 14 days and remained elevated at 21 and 28 days. The MT concentrations increased after 14 days and remained elevated throughout the experimental period. The concentrations of MT-bound zinc increased in association with the elevation in MT concentrations in the oestradiol-treated rainbow trout. These findings indicate that MT is involved in the regulation of zinc during the period of vitellogenin induction and that MT may function by maintaining the pool of available zinc at an appropriate concentration.

Suspended sediment pulse effects in rainbow trout (Oncorhynchus mykiss) — relating apical and systemic responses

2013 ◽  
Vol 70 (4) ◽  
pp. 630-641 ◽  
Author(s):  
Christian Michel ◽  
Heike Schmidt-Posthaus ◽  
Patricia Burkhardt-Holm
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Condition Factor ◽  
Mineral Particle ◽  
Physical Damage ◽  
Tubular Cells ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Metabolic Adaptations ◽  
Systemic Responses ◽  
Somatic Index

To provide an integrated perspective on mineral particle effects in salmonids, juvenile rainbow trout (Oncorhynchus mykiss) were exposed to daily mica particle pulses for 8 and 24 days. On day 8, increased immature erythrocyte proportions indicated a previous stress response. This response was absent on day 24, on which condition factor as well as plasma protein and aspartate aminotransferase activity decreased. The latter two related negatively to the hepato-somatic index, suggesting metabolic adaptations. The hepato-somatic index increased on days 8 and 24, while spleen-somatic index increased on day 24. No histopathological damage occurred in gills, liver, spleen, or kidney. However, splenic melano-macrophages increased on both days, and hyaline degenerations of kidney tubular cells were apparent on day 24. Overall, particle pulses affected rainbow trout more via turbidity rather than by physical damage. We conclude that (i) rainbow trout may adapt to sediment pulses as early as 8 days of exposure and (ii) particle pulses over 24 days can cause structural and metabolic changes in rainbow trout, even when gill damage is absent and apical effects on condition are moderate.

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