J. Neurochem. (2012) 122, 356–362.
Abstract
We found that tryptic digest of ovalbumin after oral (p.o.) and intraperitoneal (i.p.) administration exhibited anxiolytic‐like activity in mice, and then searched for orally active low‐molecular‐weight peptides with anxiolytic‐like activity in the tryptic digest. Val‐Tyr‐Leu‐Pro‐Arg, named ovolin, corresponding to ovalbumin (280‐284), mimicked the anxiolytic‐like activity after p.o. and i.p. administration. The anxiolytic‐like activity of ovolin was inhibited by indomethacin, a cyclooxygenase (COX) inhibitor, or BWA868C, an antagonist of the DP1 receptor for prostaglandin (PG) D2. Ovolin‐induced anxiolytic‐like activity was also blocked by SCH58261 or bicuculline, antagonists of the adenosine A2A and GABAA receptors, respectively. Ovolin has no affinity for the DP1, A2A and GABAA receptors. Taken together, ovolin may exhibit anxiolytic‐like activity in a manner dependent on the PGD2‐DP1 system coupled to the A2A and GABAA receptors.