اثر گرسنگي بر سطح كلسترول، گلوكز و پروتئين پلاسماي خون قزل آلاي رنگين كمان ONCORHYNCHUSMYKISS

Effects of Starvation on Plasma Levels of Cholesterol, Glucose and Protein in Rainbow Trout, Oncorhynchus mykiss

The influence of starvation on cholesterol, glucose, and protein plasma levels and tissue gluconeogensis was assesed. After acclimation to the experimental conditions, two groups of 45 fish were assigned to two outdoor concrete tanks (4mx2.7mxl.5m). Before starting the experiment, fish were fed twice daily at the rate of 1.7 % body weight with the commercial diet. Upon starting the experiment, one group of fish was deprived of food and the second group continued receiving food on similar basis. Sampling was carried out at the beginning and 10 days intervals up to 60 days by taking five fish randomly from each group. Blood samples were obtained from tail vein, centrifuged to extract serum for measuring cholesterol, glucose, and protein spectrophotometrically. Results showed a decline in cholesterol level at early days and increased towards the end of the experiment, so that no significant differences between fed and unfed group was found. Significant differences was found between serum protein level of fed (4.50 mg/dl) and unfed (3.74 mg/dl) fish (p<0.05). Blood glucose levels declined significantly, reaching from 113.90 to 60.60 mg/dl in unfed fish (p<0.05), whereas in fed fish remained unchanged. The results also suggest that rainbow trout are well adapted for prolonged starvation and glycogen and lipid body reserves meets the metabolic requirements during feed deprivation. The effects of gluconeogensis on fat tissues and changes in blood cholesterol level are discussed.