Change of Blood Sugar and Plasma Insulin Levels of Fishes in Glucose Tolerance Test

Abstract

In order to compare the ability to utilize carbohydrate of carp Cyprinus carpio, red sea bream Chrysophrys major, and yellowtail Seriola quinqueradiata (which were reared on the diets with 0%, 10%, and 40% dextrin for 30 days), they were subjected to a glucose tolerance test. The fishes istration than the response of normal human beings. The glucose tolerance of yellowtail was lowest, followed by red sea bream, and carp in increasing order. The fishes exhibited a similar pattern of change in plasma insulin levels after the administration of glucose. However, the maximum level of plasma insulin and a ratio of the maximum plasma insulin level to the maximum blood sugar level (Max. IRI/Max. BS) was lowest in yellowtail, followed by red sea bream and carp in increasing order. Futhermore, in all species, the 40% dextrin diet groups showed a higher response of blood sugar, a lower response of insulin, and a lower value of Max. IRI/Max. BS than those of the 0% and 10% groups.