Synonyms:GCAP II, GCAP II Uroguanylin, Guanylate cyclase activator 2B, GUCA2B, UGN Background:Uroguanylin, also named as GUCA2B, is a candidate intestinal natriuretic hormone that controls the sodium and water balance between the intestine and the kidneys. It has been reported that the uroguanylin knockout mouse exhibits elevated blood pressure. Therefore, the GUCA2B gene is thought to be a susceptibility gene for essential hypertension(EH).