Okadaic acid decreases the leptin content in isolated mouse fat pads.

Okadaic acid (OA) decreased the leptin content in isolated mouse fat pads in a time and dose-dependent manner. MG-132, a membrane-permeable proteasome inhibitor, prevented the decrease by OA, suggesting the involvement of proteasome in the OA action. No significant decrease in the incorporation of [(3)H]leucine into leptin was observed with a 4-h incubation, although the amino acid incorporation was stimulated by insulin and decreased by cycloheximide.