ISSN:
0095-9898
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
Glucocorticoid administration produces an increase in precursor incorporation into rat liver glutamic-alanine transaminase in the whole animal and in liver preparations incubated in vitro. The augmented incorporating ability was present in both the microsomal and cell sap fractions. The effect both in vivo and in vitro was specific, with little or no increase observed in the total soluble protein pool of the cell. From these results, together with information obtained from measurements of the biological half-life of the enzyme, it is concluded that the increase in tissue level of the enzyme consequent to glucocorticoid administration results from an increased rate of biosynthesis. The possible role of environmental control of enzyme levels in cells through effects on degradation rates is discussed. The increased rate of precursor incorporation into liver glutamic-alanine transaminase in vivo was aleady at a maximum value 12 hours after initiation of hormone administration, in contrast to the enzyme level which had not increased by 12 hours and reached a peak only after 5 days. These findings suggest the possibility that there is a simultaneous induction by glucocorticoids of all the liver enzymes responsive to the hormone.
Additional Material:
4 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcp.1030660404
Permalink
