A substance,usually a peptide or steroid,produced by one tissue and conveyed by the bloodstream to another to effect physiological activity,such as growth or metabolism.

• 荷尔蒙一种物质，通常为肽或类固醇，由一组织产生，经由血液循环到达另一组织来影响生理活动，例如生长或新陈代谢。