Alterations in sympathetic nervous system activity do not regulate adipsin gene expression in mice

Area of Science:

• Adipose tissue biology
• Neuroendocrinology
• Obesity research

Background:

• Adipsin gene expression is reduced in rodent obesity models with decreased sympathetic nervous system (SNS) activity.
• Sympathomimetic drugs reversed obesity and restored adipsin levels in obese mice, suggesting SNS regulation of adipsin.

Purpose of the Study:

• To investigate the role of the sympathetic nervous system (SNS) in regulating adipsin gene expression.
• To determine if altered SNS activity impacts adipsin levels in normal mice.

Main Methods:

• Mice were exposed to cold (4°C) to activate SNS.
• Mice underwent chemical sympathectomy using 60H-dopamine.
• Lean mice were treated with an atypical beta-adrenoreceptor agonist (BRL 26830A).
• Adipsin mRNA levels in white (WAT) and brown adipose tissue (BAT) and serum adipsin concentrations were measured.

Main Results:

• Cold exposure and sympathectomy did not alter serum adipsin or adipsin mRNA levels in normal mice.
• Treatment with BRL 26830A significantly decreased both serum adipsin concentrations and adipsin mRNA levels.
• These findings contradict the initial hypothesis that SNS activity regulates adipsin expression.

Conclusions:

• SNS activity does not appear to regulate adipsin gene expression in normal mice.
• Atypical beta-adrenoreceptor agonists may suppress adipsin expression in vivo.
• Further research is needed to elucidate the mechanisms and physiological significance of BRL 26830A-induced adipsin suppression.