Catecholamine and Endocrine

Catecholamine noun - Any of a group of chemicals including epinephrine and norepinephrine that are produced in the medulla of the adrenal gland.

Endocrine and catecholamine are semantically related. In some cases you can use "Endocrine" instead a noun "Catecholamine".

Endocrine noun - Any of the glands of the endocrine system that secrete hormones directly into the bloodstream.

Catecholamine and endocrine are semantically related. Sometimes you can replace term "Catecholamine" with "Endocrine", this nouns are similar.