Signalling molecule secreted into circulation by endocrine gland, acting on distant target tissues. Classes: peptide/protein (insulin), steroid (cortisol), amine (epinephrine, T3), eicosanoid.
Signalling molecule secreted into circulation by endocrine gland, acting on distant target tissues. Classes: peptide/protein (insulin), steroid (cortisol), amine (epinephrine, T3), eicosanoid.