Changes in Behavior and Blood Corticosterone Level in Male and Female Rats after Single Administration of Obestatin Fragment 1-4.

Single administration of the obestatin fragment 1-4 (300 nmol/kg) to male Wistar rats produced a significant weight loss in male rats on observation days 5-8, while in female rats only on day 8. In addition, males demonstrated decreased risk factor in the elevated plus-maze test, but no effect of the preparation on behavior of female rats was revealed. Obestatin fragment 1-4 had no effect on corticosterone level 1 week after single administration in both females and male rats.

Antioxidant Defense System after Single and Chronic Administration of Obestatin and Its Fragment (1-4) to Normal and Overweight Male Rats.

We studied the effects of anorectic peptide obestatin and its fragment (1-4) on the antioxidant defense system in animals with normal and experimentally induced increased body weight. In rats with normal body weight, no changes in activity of the antioxidant defense system 1 week after single administration of the substances. After chronic administration of obestatin and fragment (1-4) for 1 week, total antioxidant capacity of the plasma decreased; obestatin also lowered the content of TBA-reactive products. In the overweight rats, SOD-like activity in the plasma increased 1 week after chronic administration of obestatin. Hence, obestatin and its fragment (1-4) induced changes in the antioxidant defense system only after chronic administration.