The effect of cortisol administration on hepatic and plasma estradiol-binding capacity in immature female rainbow trout (Oncorhynchus mykiss).
Implantation of a cortisol-containing pellet into the peritoneal cavity of immature female rainbow trout raised plasma cortisol levels within the range commonly observed in chronically stressed fish. In cortisol-implanted fish there was a significant decline in the concentration of hepatic estradiol-binding sites relative to sham-implanted controls. This consisted of a 35% drop in cytosolic binding sites and a 29% reduction in the number of nuclear estradiol-binding sites, by 4 weeks postimplantation. Plasma estradiol-binding capacity was also influenced by cortisol treatment. After 2 weeks there was a 33% increase in plasma estradiol-binding capacity of cortisol-implanted fish. Plasma estradiol levels were unaffected by cortisol implantation, suggesting that the effects of cortisol on estradiol-binding sites were not mediated by altering the rate of estradiol secretion. The results indicate a possible mechanism by which environmental stress may suppress vitellogenesis.
Pottinger
T G
TG
Institute of Freshwater Ecology, Ambleside, Cumbria, United Kingdom.
Pickering
A D
AD
D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D004958:Estradiol / Q000097:blood / Q000378:metabolism*; D005260:Female; D006854:Hydrocortisone / Q000097:blood / Q000494:pharmacology*; D008099:Liver / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D011959:Receptors, Estradiol / Q000187:drug effects / Q000378:metabolism*; D014337:Trout / Q000378:metabolism*; D014818:Vitellogenesis
D011959:Receptors, Estradiol; D004958:Estradiol; D006854:Hydrocortisone