The invention provides methods of modulating gastric acid secretion by administering an amount of a prokineticin receptor antagonist effective to alter one or more indicia of gastric acid secretion, wherein the antagonist contains an amino acid sequence at least 80% identical to amino acids to 7 to 77 of SEQ ID NO:3, which includes (a) the 10 conserved cysteine residues of SEQ ID NO:3, and (b) from 0 to 9 of amino acids 78 to 86 of SEQ ID NO:3, wherein amino acids 1 to 6 of the antagonist do not consist of amino acids AVITGA (SEQ ID NO:21). In another embodiment, the antagonist contains an amino acid sequence at least 80% identical to amino acids to 7 to 77 of SEQ ID NO:6, which includes (a) the 10 conserved cysteine residues of SEQ ID NO:6, and (b) from 0 to 4 of amino acids 78 to 81 of SEQ ID NO:6, wherein amino acids 1 to 6 of the antagonist do not consist of amino acids AVITGA (SEQ ID NO:21).