[Modulations by stimulation of angiotensin II type 1 receptor of gastrointestinal functions]

Electrolytes and water are bidirectionally transported across the epithelial cells of mammalian small and large intestines. In animals with chronic renal failure, plasma levels of angiotensin II and specific 125I-angiotensin II binding sites increase and result in enhanced excretions of K+, Cl- and urate from distal colon, in an AT1-receptor sensitive manner. Angiotensin-converting enzyme activity and mRNA levels for renin-2 and AT1A-receptor are blunted or lowered transiently by gastric intake of low Na+ in rodent, suggesting that angiotensin II serves as a humoral mediator for "gastric Na+ monitor". Angiotensin II causes also very potent contractions of gastrointestinal smooth muscles as shown in vascular smooth muscles. This review is focused on understanding potential roles of angiotensin II in gastrointestinal functions.