The Development of Angiotensin II - induced Hypertension During Various Salt Intakes in Cre/lox Conditional Knockout Mice for Bradykinin Receptors in The Collecting Duct

Bradykinin is an important antihypertensive peptide acting mostly via the kinin B2 receptor (gene: Bdkrb2; protein: B2R). We elucidated the role of collecting duct B2R in the development of salt-sensitivity and angiotensin II (ANG II)-induced hypertension. We used a Cre-Lox recombination strategy to generate mice lacking Bdkrb2 gene for B2R in the collecting duct (Hoxb7-Cretg/+:Bdkrb2flox/flox). In 3 groups of control (Bdkrb2flox/flox) and 3 groups of UBBdkrb2-/- mice, systolic blood pressure (SBP) responses to high salt intake (4 or 8% NaCl; HS) were monitored by radiotelemetry in comparison with standard salt diet (0.4% NaCl) prior to and during subcutaneous ANG II infusion (1000 ng/min/kg) via osmotic pumps. High salt intakes alone for 2 weeks did not alter SBP in either strain. ANG II significantly increased SBP equally in control (121 ± 2 to 156 ± 3 mmHg) and UBBdkrb2-/- mice (120 ± 2 to 153 ± 2 mmHg). The development of ANG II-induced hypertension was exacerbated by 4%HS in both control (125 ± 3 to ...