The potential role of angiotensin II in the vasculature.

Arterial hypertension is associated with marked changes in the structure of both resistance and large arteries. The renin-angiotensin system is largely involved in these alterations; chronic blockade of the renin-angiotensin system prevents and/or reverses most of the alterations of the vasculature in experimental and clinical hypertension. In this review we have analysed the differential role of AT1 and AT2 receptors in the response of the vessels to arterial hypertension. It emerges that the relative involvement of each receptor depends on cell type, the studied specie, and experimental condition. Several points must be investigated in the near future, and especially: (1) the precise role of angiotensin receptors in different cell types and different stages of differentiation; (2)the transduction pathway used by the AT2 receptor in different cell types; (3) the possible interactions between the two receptor subtypes; and finally, (4) a possible role of (a) new subtype(s) of angiotensin II receptor.