Coda 8

The CODA-8 (Kent Scientific) noninvasive volume pressure recording tail-cuff BP system was employed to record BP measurements as performed previously [2 (link)]. Offspring were acclimated to the machine beginning at week 3 and measurements began at week 4 and ran until sacrifice at the end of week 14. Animals were also acclimated to the machine for 10 minutes prior to measurements. A total of 25 readings were taken per day over the course of 25 minutes, and three days of each week were recorded to form an average measurement per week. Measurements were recorded prior to any husbandry duties and within the hours of 9 am to 6 pm to avoid diurnal variation in BP.

Two to three days before euthanasia, ECG and blood pressure were non-invasively recorded in rats from both control and T1D groups. For each animal, ECG lasting at least 15 min was recorded in three limb leads using ecgTUNNEL (EMKA Technologies, Paris, France). Standard ECG peaks (P, Q, R, S, T) and intervals (RR, PQ, QRS, and QT) were assessed from approximately ten beats using ECG auto software (EMKA Technologies, Paris, France). Periods with motion artifacts were excluded from the analysis. The QT interval was corrected according to Fridericia’s formula (QTcF) [23 (link)]. TcFP interval was calculated using the following formula: RR − PQ − QTcF.
Blood pressure measurements were performed using CODA 8 (Kent Scientific Corporation, Torrington, CT, United States) for at least 15 min for each animal. The systolic and diastolic pressure values and tail blood flow velocity were defined as means calculated from 10 measuring cycles in each measurement.

Pups from each group were sexed and weaned at 3 weeks of age and separated into groups of 2–3. Body weight was recorded from week 3 forward to reduce early life handling stress which has been shown to impact HPA-axis, which may skew results [25 (link)]. Blood pressure measurements were recorded using the non-invasive volume blood pressure system CODA 8 (Kent Scientific, Torrington, CT, USA) as depicted previously [6 (link),7 (link)]. The CODA 8 high throughput system involves the animal being placed into a plexiglass tube and gentle warming on the warming pad provided. Pups were acclimated to restraint and the blood pressure system for a week before measurements (week 3) and for 10 min prior to recording each day’s measurements. Blood pressure was measured thrice a week from weeks 4–14, as previously described [6 (link),7 (link)]. Care was taken to ensure measurements were taken prior to any husbandry practices and between 9 a.m. and 6 p.m. to prevent natural diurnal fluctuations in blood pressure.

Blood pressure, heart rate, and activity were measured using a radiotelemetry (PA-C10, DSI), as previously described^{10 (link)–12 (link)} in AngII-infused C57BL/6J mice. For the characterization of the systemic dose of αAnalogue, blood pressure was measured by tail-cuff plethysmography (CODA 8, Kent Scientific) in conscious mice.^{7 (link),10 (link)} Following AAC-induced cardiac hypertrophy, blood pressure was measured via carotid artery in anesthetized mice.