( Gastrin ( ( is ( ( the hormone ) ( responsible ( for ( gastric secretion ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Gastrin)) (VP (VBZ is) (NP (NP (DT the) (NN hormone)) (ADJP (JJ responsible) (PP (IN for) (NP (JJ gastric) (NN secretion)))))) (. .)))
Gastrin is the hormone responsible for gastric secretion.
(ROOT (S (NP (NNP Gastrin)) (VP (VBZ signals) (NP (NP (DT the) (NN secretion)) (PP (IN of) (NP (JJ gastric) (NN acid))))) (. .)))