GI hormones vs gastrin

GI hormones and gastrin both are nouns.

Word	Noun	Adjective	Verb	Adverb
GI hormones	Yes	No	No	No
gastrin	Yes	No	No	No

As nouns, gastrin is a hyponym of GI hormones; that is, gastrin is a word with a more specific, narrower meaning than GI hormones:

GI hormones: hormones that affect gastrointestinal functioning
gastrin: polypeptide hormone secreted by the mucous lining of the stomach; when peptides and amino acids are present in the small intestine the secretion of gastric acid is stimulated

Other hyponyms of GI hormones include cholecystokinin, secretin, ghrelin, motilin.

GI hormones (noun)	gastrin (noun)
hormones that affect gastrointestinal functioning	polypeptide hormone secreted by the mucous lining of the stomach; when peptides and amino acids are present in the small intestine the secretion of gastric acid is stimulated