Abstract
Relationship between the dietary protein levels (0.8 and 20%) and enzyme activities of liver (hexokinase, glucose-6-phosphate dehydrogenase, glucose-6-phosphatase, arginase and serine dehydratase) was studied on rats administered insulin for three weeks.
Although higher level of protein in diets brought the better growth of rats, insulin (1 iu/100g body weight/day) injected intraperitoneally affected scarcely (at any protein level) on the growth rate as well as on dietary intake.
In rats fed a protein-free diet, hexokinase, glucose-6-phosphatase and serine dehydratase little responded to insulin, but glucose-6-phosphate dehydrogenase activity was increased twice as much as the control.
In the low (8%) protein level, activities of hexokinase and glucose-6-phosphatase increased about 100% and 40%, respectively, with insulin administration.
In the normal (20%) protein level, activities of hexokinase increased 240%, while glucose-6-phosphate dehydrogenase and arginase decreased about 40% in response to insulin administration.
Some discrepancy on the behavior of glucose-6-phosphate dehydrogenase between the present results and those obtained in other laboratories with shorter period (less than a week) of insulin administration was discussed.
