<prompt> Which of the following statements about Histamine is true:Is found in Mast cellsIncreases gastric acid secretionRelated to arousal and blood pressureAll of the above  <response>: D i.e. All Histamine is formed by decarboxylation of amino acid histidineQ, and is found in mast cell, basophils, enterochromaffin like cells of gastric mucosa and brainQ. It has been related to arousal, sexual behaviourQ, regulation of secretion of some anterior pituitary hormones, blood pressure, drinking pain threshold. 