blood hormone amount EFO:0008391 VT:0005418 ATOL:0000527 EFO:0007972 CMO:0003032 blood hormone content CMO:0003030 EFO:0010245 Trait.ontology The proportion, quantity, or volume in whole blood, serum, or plasma of any of the chemical substances that have specific regulatory effects on the activity of a certain organ or organs; originally applied to substances secreted by various endocrine glands and transported in the bloodstream to the target organs, it is sometimes extended to include substances that are not produced by the endocrine glands but that have similar effects. circulating hormone level EFO:0004769 EFO:0020621 EFO:0004730 EFO:0020363 blood molecular composition trait