Effects of oleamide and N-oleoylglycine administration on serum levels of oleamide. Groups of rats (N=8) were administered either vehicle, oleoylglycine (80 mg/kg) or oleamide (80 mg/kg) via intraperitoneal injection. After 60 min, the animals were sacrificed, blood samples collected and serum oleamide levels measured by ELISA as described under Materials and Methods. Circulating levels of oleamide were 16 ± 4 ng/ml, 27 ± 6 ng/ml and 209 ± 64 ng/mL for the vehicle control, oleoylglycine and oleamide treatment groups, respectively. * p<0.01