- Studies on the ileum-contracting mechanisms and identification as a complement C3a receptor agonist of oryzatensin, a bioactive peptide derived from rice albumin. Takahashi, M., Moriguchi, S., Ikeno, M., Kono, S., Ohata, K., Usui, H., Kurahashi, K., Sasaki, R., Yoshikawa, M. Peptides (1996)