Aims: 

Obestatin is a 23 amino acid ghrelin-associated peptide, produced in the gastric mucosa from preproghrelin. Both ghrelin and obestatin are considered multifunctional, being involved in the control of energy balance and modulation of higher brain functions, such as learning, memory and anxiety-like behavioral patterns.

Methods: 

We investigated whether the centrally administered obestatin could influence the effects of morphine on locomotion and anxiety in CFLP mice. Conducta system was used for the experiments, which was specifically designed to monitor the different motoric and behavioral patterns of rodents, such as vertical (jumping) and horizontal activity (distance travelled in cm and ambulation time), rearing, as well as percent time spent in center area, as a marker for anxiety.

Results: 

Co-treatment with obestatin (0.8 mg/2ml aCSF) and morphine (2 mg /kgbw s.c.) significantly increased the distance travelled in cm, compared to the morphine-treated group, while ambulation time remained unchanged. The number of rearings was decreased when morphine was given alone and in combination with obestatin, 1.5mg/2ml aCSF. The injection of morphine alone or together with obestatin decreased the number of jumpings. Obestatin when given alone or in combination with morphine caused a significant decrease in percent time spent in the center area of Conducta system,compared to control animals.The most prominent anxiogenic effect was observed after combined injection of Obestatin (1.5mg/2ml aCSF) and morphine.

Conclusions: 

Several studies have demonstrated a strong correlation between hedonic reward systems, energy homeostasis and compulsive addictive behaviors such as eating disorders and drug abuse. According to our preliminary findings, obestatin might modulate the behavioral effects of morphine. Further studies are needed however to exactly elucidate the metabolic and behavioral properties of this pleiotropic peptide.

Support: 

ETT 355-08/2009 and TÁMOP 4.2.1B