Differential effects of local versus systemic angiotensin II in the regulation of leptin release from adipocytes.

Adipocytes secrete a variety of factors, including angiotensinogen, the only known precursor to Angiotensin II (AngII). Recent studies suggest that adipocyte-derived angiotensinogen can contribute to circulating angiotensinogen concentrations and modulate blood pressure; however, an autocrine role for adipocyte-derived angiotensinogen and/or AngII has not been well defined. We sought to determine whether locally produced AngII influences the release of leptin from adipocytes and thus circulating leptin concentrations. In adipocytes from rats treated for 3 d with captopril demonstrating reductions in AngII release, leptin release and plasma leptin concentration were decreased. Incubation of adipocytes with AngII resulted in an increase in leptin mRNA expression and leptin release. To determine the effect of elevated systemic AngII on leptin, rats were infused with AngII (175 ng/kg·min) or saline for 1, 2, or 7 d. Plasma leptin concentration progressively declined with duration of AngII exposure. Basal and ...