Abstract
Abstract The responses of the adaptive enzymes, serine dehydrase (l-serine hydro-lyase (deaminating), EC 4.2.1.13), ornithine transaminase (l-ornithine: 2-oxoacid aminotransferase, EC 2.6.1.13), glucose 6-phosphate dehydrogenase (d-glucose 6-phosphate:NADP oxidoreductase, EC 1.1.1.49), and glucokinase (ATP:d-glucose 6-phosphotransferase, EC 2.7.1.2), in rat liver were studied in relation to changes in the level of dietary protein and treatments with cortisone. The administration of cortisone markedly altered the responses of the enzymes to the diet, and the effects of the hormone depended both on the route of its administration (intraperitoneal or intramuscular injection) and on the dietary regimen of the rats. The response of each enzyme to the regulatory stimuli (diet and cortisone) showed elements of both uniqueness and similarity with respect to the responses of the other three enzymes to these stimuli. The results indicate that the regulatory system for each enzyme responds to a specific set of effectors (e.g. amino acids or carbohydrate or both, of dietary or endogenous origin) and that cortisone alters the capacity of the regulatory systems to interact with the appropriate effectors.
Highlights
2.7.1.2), in rat liver were studied in relation to changes in the level of dietary protein and treatments with cortisone
The presence of glucocorticoids is not required for the induction of these enzymes (I), cortisone treatment permits the dietary induction of these enzymes in the presence of a normally inhibitory amount of dietary carbohydrate [6]
Cortisone alone does not cause their induction, under these conditions. These findings indicate that cortisone exerts a regulatory influ
Summary
Male Sprague-Dawley rats were obtained at an age of 5 weeks (body weight, 100 to 150 g) from the animal facilities of the Biology Division at Argonne, and were housed under conditions of constant temperature (25O) and regulat,ed lighting (12 hours of light and 12 hours of dark). They had free access to food and water. Adrenalectomies were performed on some of these rats, when they were 5 weeks old, at the Hormone Assay Laboratories, Inc., Chicago They were given both food and 1% NaCl solution ad Zibitum thereafter, and were placed on experiment on the 7th day after adrenalectomy. A standard laboratory animal diet, containing 24% protein (Wayne Lab Blox, Allied Mills, Inc., Chicago, Illinois), was given in some cases
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
