Effect of acute exercise on cardiovascular hemodynamic and red blood cell concentrations of purine nucleotides in hypertensive compared with normotensives rats

Abstract

SHRs were more tolerant to increases in HR and SBP induced by exercise, and have more profound postexercise hemodynamic effects than SDRs. The hemodynamic effects were linked closely with RBC concentrations of ATP and GTP in both SDRs and SHRs.

A Pilot Study to Assess Adenosine 5’-triphosphate Metabolism in Red Blood Cells as a Drug Target for Potential Cardiovascular Protection

“…It also significantly increased RBC concentrations of ATP which may contribute to the post exercise BP effects [35, 36]. Our current study found similar results with significantly higher RBC ATP levels in the LowEx group more than one hour after the exercise compared to the other groups (Fig.…”

“…In addition, a significant increase of RBC ATP concentrations was found in the rats with exercise (LowEx and VigEx) and also in those without receiving isoproterenol (NoIso) (p < 0.05 paired t-test), but not in the NoEx group (Table 3 ). We have previously observed an increase in RBC ATP concentrations in rats even when they were kept in a restrainer and the increase was greater in SHR than in SDR [36]. The mechanism for the increase ATP concentrations in the RBC in the NoIso group is not currently known.…”

“…After 2 brief sessions of 3 – 5 minutes (min) each of training to acclimatize the rat with the treadmill on the day before the study, each rat was exercised on the treadmill for 15 min at 10 m/min and 10% grade 
(n = 7) (LowEx), or 15 min at 14 m/min and 22% grade 
(n = 8) (VigEx). Another group of rats without exercise was used as control (NoEx, n = 10) as described previously [35, 36]. Two hours after the exercise, each rat received a single dose of isoproterenol (30 mg/kg) by subcutaneous (sc) injection.…”

“…The total length of the experiment was about 6 hrs from the start of the final exercise. Hemodynamic variables (SBP, DBP and HR) were continuously recorded (except interrupted briefly during each blood sample collection) via the intra-vascular catheter using a TruWave ® disposable pressure transducer (Model PX601, Edwards Lifesciences Canada, Inc., Mississauga, ON, Canada) coupled to a Siemens hemodynamic monitor (Sirecust ® 400) and chart recorder (Siredoc ® ) (Erlangen, FRG) as previously described [35, 36]. The hemodynamic data presented were averages of 10 – 15 seconds (sec) recording.…”

“…Previous studies have shown that exercise preconditioning offered cardioprotective effect against injury induced by isoproterenol in rats [32, 33], and cardiotoxicity induced by doxorubicin [34]. We have recently shown that exercise improved cardio-
vascular hemodynamic profiles and increased red blood cell (RBC) concentrations of ATP in both normotensive Sprague Dawley rat (SDR) and spontaneously hypertensive rats (SHR) although the post exercise effects were more profound in the SHR [35, 36]. The increase of ATP concentrations in the RBC may be a key contributing factor for the acute effects of post exercise preconditioning and in the long term effects of program of regular exercise in cardiovascular protection.…”