During their development from progenitor cells, adipocytes not only express enzymatic
activities necessary for the storage of triglycerides, but also achieve the capability
to produce a number of endocrine factors such as leptin, tumor necrosis factor α (TNFα),
complement factors, adiponectin/adipoQ, plasminogen activator inhibitor-1 (PAI-1),
angiotensin II and others. Angiotensin II is produced from angiotensinogen by the
proteolytic action of renin and angiotensin-converting enzyme; and several data point
to the existence of a complete local renin-angiotensin system in adipose tissue, including
angiotensin II receptors. In this study, we directly monitored the production of angiotensin
II type one receptor (AT1) and angiotensin II type two receptor (AT2) proteins during
the adipose conversion of murine 3T3-L1 preadipocytes by immunodetection with specific
antibodies. AT1 receptors could be detected throughout the whole differentiation period.
The strong AT2 signal in preadipocytes however was completely lost during the course
of differentiation, which suggests that expression of AT2 receptors is inversely correlated
to the adipose conversion program.
Key words
Renin-Angiotensin System - Metabolic Syndrome - Adiposity - Adipocyte Development
