AdipoRon exerts opposing effects on insulin sensitivity via fibroblast growth factor 21-mediated time-dependent mechanisms.

Increasing evidence has shown that AdipoRon, a synthetic adiponectin receptor agonist, is involved in the regulation of whole-body insulin sensitivity and energy homeostasis. However, the mechanisms underlying these alterations remain unclear. Here, using hyperinsulinemic-euglycemic clamp and isotopic tracing techniques, we show that short-term (10 days) AdipoRon administration indirectly inhibits lipolysis in white adipose tissue via increasing circulating levels of fibroblast growth factor 21 in mice fed a high-fat diet. This led to reduced plasma-free fatty acid concentrations and improved lipid-induced whole-body insulin resistance. In contrast, we found that long-term (20 days) AdipoRon administration directly exacerbated white adipose tissue lipolysis, increased hepatic gluconeogenesis, and impaired the tricarboxylic acid cycle in the skeletal muscle, resulting in aggravated whole-body insulin resistance. Together, these data provide new insights into the comprehensive understanding of multifaceted functional complexity of AdipoRon.