(B), regulation by endothelin (EDN1); (C), regulation of natruretic peptide (NPPA, NPPB, NPPC); and (D), the bradykinin-killikrien pathway. Figure 7 shows a simplified version of the pathways and their inter-relationships, derived from browsing the interface, reviews [68,69], and on-line data [70]. The pathways are highly interconnected. For example, both natruretic peptide and bradykinin also act as antagonists of the rennin-angiotensin pathway, and are able to relax vascular contraction and down-regulate blood pressure. Conversely, ACE, which activates AGT in the renin-angiotensin pathway, can inactivate bradykinin.
