The hph-1 mice (originally in CBA background) 19 (link) were backcrossed with C57BL6 mice for more than 10 generations and genotyped based on a protocol by Koo et al. 21 (link). Only homozygote hph-1 mice were used for experiments. Wild-type (WT) and hph-1 male mice at 24 weeks of age were infused with Ang II (0.7 mg/kg/day) using subcutaneously implanted osmotic pumps (Durect Corp.). During the 14-day infusion, blood pressure was monitored by telemetry method. Wireless blood pressure probes were implanted into the animals 10 days prior to the implantation of the osmotic pumps. The catheter of the blood pressure probe was inserted into the left carotid artery, while the body of the probe was inserted into the right flank. Animals were given 1 week to recover from the surgery. After this period, blood pressure was measured for 3 days to obtain a baseline. The osmotic pumps were then implanted on the 10th day after surgery. Measurements were made daily from 9am to 4pm at 250 Hz sampling rate. Average blood pressure was calculated daily as the average of the entire recording period. The use of animals and experimental procedures were approved by the Institutional Animal Care and Usage Committee at the University of California Los Angeles (UCLA).
Electron spin resonance determination of aortic nitric oxide and superoxide production, HPLC determination of aortic H4B content, and Western Blot determination of endothelial DHFR expression were performed as previously published 1 (link),2 (link).
Electron spin resonance determination of aortic nitric oxide and superoxide production, HPLC determination of aortic H4B content, and Western Blot determination of endothelial DHFR expression were performed as previously published 1 (link),2 (link).
