Effects of food deprivation and handling stress on head kidney 17alpha-hydroxyprogesterone 21-hydroxylase activity, plasma cortisol and the activities of liver detoxification enzymes in rainbow trout.
The 21-hydroxylation of 17alpha-hydroxyprogesterone is one step in the biosynthesis of corticosteroids. Both 7 days of handling-induced stress and 7 weeks of food deprivation significantly elevated head kidney microsomal 17alpha-hydroxyprogesterone 21-hydroxylase activity in juvenile rainbow trout. The increased 21-hydroxylase activity was not paralleled by changes in plasma cortisol levels induced by handling stress whereas food deprivation for 3 and 7 weeks increased both 21-hydroxylase activity and plasma cortisol levels significantly. Food deprivation in rainbow trout affected detoxification enzyme activities, namely glutathione-S-transferase (GST), uridine-di-phosphate glucuronosyltransferase (UGT) and glutathione reductase (GR) activities in the liver. Together our observations suggest that experimental conditions can affect experimental results, especially the values of parameters like GST, UGT and GR. Furthermore, alterations in the metabolic state of the liver caused by stress or food deprivation can alter the balance between detoxification enzymes in rainbow trout liver.
Blom
S
Department of Zoophysiology, University of Gotenburg, Box 463, SE 405 30, Gotenburg, Sweden
Andersson
TB
Förlin
L