The renin-angiotensin system in the bovine utero-placental unit

Renin, angiotensin converting enzyme, and angiotensin II receptors are expr essed in the bovine utero-placental unit, indicating the presence of a loca l renin-angiotensin system (RAS). Angiotensin II receptors of type AT(1) an d AT(2) as well as non-AT(1)/non-AT(2) binding sites were identified. The e xpression of both renin and the angiotensin II receptor types in the bovine utero-placental unit differs from that in humans. This fact is probably re lated to differences in placental architecture. The RAS in the bovine utero -placental unit might be important for growth processes in the endometrium and for placentation. It might also participate in the regulation of the ut ero-placental blood flow and secretion of hormones. Disturbances in the ute ro-placental RAS might cause a reduced utero-placental blood flow, intraute rine growth retardation and intrauterine death.