Induction of Angiotensinogen mRNA in Hepatocytes by Angiotensin II and Glucocorticoids

ABSTRACT

In isolated rat hepatocytes, exposed to angiotensin II and glucocorticoids, angiotensinogen mRNA increased within 30-60 min, and angiotensinogen secretion with a time lag of about 2 hours. After 4 hours, angiotensinogen mRNA, estimated by liquid hybridization with radiolabeled cRNA, was 5.9 ± 0.4 in control, and 10.8 ± 0.8, 11.7 ± 0.4, 16.1 ± 0.8 and 21.7 ± 0.2 pg/μg of total RNA in cells exposed to angiotensin II (9 nM and 90 nM), hydrocortisone (100 μM) and dexamethasone (10 μM) respectively. The corresponding secretion rates of angiotensinogen were 72 ± 7, 124 ± 4, 132 ± 12, 220 ± 19 and 217 ± 18 fmol angiotensinogen/mg wet weight/hour. Thus, angiotensin II stimulates angiotensinogen synthesis and secretion by acting at a pretranslational site.

Key words::

• Angiotensinogen
• angiotensin II
• isolated hepatocytes
• induction
• feed back control
• glucocorticoids
• renin-angiotensin-system
• secretion
• transcription
• angiotensinogen-mRNA