Leptin secretion is related to glucose-derived lipogenesis in isolated adipocytes

Abstract

Objective: Leptin secretion in rats is regulated acutely by nutritional state. Insulin plays an important role in this acute nutritional regulation both directly and indirectly through effects on glucose metabolism. The aim of this study was to investigate if the fasting-induced suppression of leptin secretion was reversed by incubation under conditions mimicking nutritional repletion. Design: Leptin secretion and glucose metabolism were measured following incubation with glucose and insulin in adipocytes isolated from fed and fasted rats. Results: Leptin secretion was stimulated by incubation with glucose and insulin in adipocytes isolated from fed but not from fasted rats as was glucose flux through oxidative and lipogenic pathways. Ob expression and intracellular leptin content were decreased in adipocytes isolated from fasted rats throughout the whole incubation period. Suppression of glucose metabolism with cytochalasin B was accompanied by suppression of leptin secretion. The amount of leptin secretion correlated with the glucose incorporated into lipid under insulin-stimulated conditions. Conclusions: It is proposed that glucose incorporation into lipid, at least during insulin-stimulated conditions, reflects the metabolic status of the adipocyte and may be a more important regulator of leptin production and secretion than circulating glucose or insulin levels.

Chronic Social Isolation Is Associated with Metabolic Gene Expression Changes Specific to Mammary Adipose Tissue

“…Both adipocyte glucose metabolism and lipid synthesis are suspected to be important regulators of production and secretion of the adipokine, leptin (32, 33). Furthermore, previous in vitro and in vivo studies have implicated leptin in cancer cell proliferation and tumor growth (34–37).…”

Activation of Peripheral Blood Mononuclear Cells and Leptin Secretion: New Potential Role of Interleukin-2 and High Mobility Group Box (HMGB)1

“…We may speculate that leptin can act in a paracrine way to increase IL-1β secretion affecting pancreatic β cell failure [ 63 ]. In adipocyte cells, insulin may induce leptin secretion and mRNA expression through a different number of potential mechanisms even if strong evidence outlines either an action mediated by cAMP (Cyclic adenosine monophosphate) [ 64 ], or through glucose metabolism and its incorporation into lipid [ 65 ]. Glucose may also modulate leptin secretion through a cAMP dependent mechanism at a concentration of 5.5 mM [ 64 ].…”

Adipocyte pyruvate dehydrogenase kinase 4 expression is associated with augmented PPARγ upregulation in early‐life programming of later obesity

“…[16], with minor modifications as described in Ref. [17]. Adipocyte numbers were determined by counting under phase‐contrast microscopy.…”