Central angiotensin 1-7 triggers brown fat thermogenesis
F S Evangelista1,2, T J Bartness2
1School of Arts, Science and Humanities, University of Sao Paulo, Sao Paulo, Brazil.
Physiological Reports
|March 11, 2023
Summary
Third ventricular injections of angiotensin 1-7 (Ang 1-7) boost brown adipose tissue (BAT) thermogenesis. This effect is mediated by the Mas receptor, highlighting its role in metabolic regulation.
Area of Science:
- Physiology
- Endocrinology
- Metabolism
Background:
- Brown adipose tissue (BAT) plays a crucial role in thermogenesis and energy expenditure.
- The renin-angiotensin system, including angiotensin 1-7 (Ang 1-7), is implicated in metabolic regulation.
- The Mas receptor is a key component of the Ang 1-7 signaling pathway.
Purpose of the Study:
- To investigate the effect of third ventricular (3V) Ang 1-7 injections on BAT thermogenesis.
- To determine if the Mas receptor mediates the thermogenic response to Ang 1-7.
- To explore the impact of Ang 1-7 on specific lipolytic enzymes in BAT.
Main Methods:
- Male Siberian hamsters received 3V injections of Ang 1-7, Mas receptor antagonist A-779, or saline.
- Interscapular BAT (IBAT) temperature and core body temperature were monitored.
- Expression of phosphorylated hormone-sensitive lipase (p-HSL) and adipose triglyceride lipase (ATGL) was assessed in IBAT.
Main Results:
- 3V Ang 1-7 administration significantly increased IBAT temperature in a dose-dependent manner.
- The thermogenic effect of Ang 1-7 was blocked by the Mas receptor antagonist A-779.
- Ang 1-7 increased p-HSL expression in IBAT, suggesting enhanced lipolysis.
Conclusions:
- Third ventricular Ang 1-7 induces thermogenesis in BAT through a Mas receptor-dependent mechanism.
- Ang 1-7 influences BAT lipolysis via modulation of HSL activity.
- These findings suggest a novel central regulatory pathway for energy expenditure involving Ang 1-7 and the Mas receptor.
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