Exercise hemodynamic and neurohormone responses as sensitive biomarkers for diltiazem in rats

Abstract

Purpose. To investigate the potential of exercise hemodyanamic and neurohormone variables as sensitive biomarkers for pre-clinical evaluation of diltiazem (DTZ). Methods. Sprague Dawley (SD) rats were randomly divided into 3 groups (n = 6-8 each), and each group received DTZ 10 mg/kg twice daily for 5 doses or saline followed by a treadmill exercise protocol for 7 min with speed set at 7 m/min at 3% grade. The 3rd group received saline but no exercise. Results. Exercise increased SBP from 108 +/- 2 to 131 +/- 3 mmHg, and HR from 437 +/- 6 to 503 +/- 6 bpm, and plasma epinephrine concentrations from 2.0 +/- 0.6 to 5.8 +/- 1.7 ng/mL in control rats (p 0.05). Conclusion. Exercise hemodynamic and neurohormone responses are sensitive biomarkers which could be used for safety and efficacy evaluation of DTZ and perhaps also other calcium antagonists in pre-clinical animal models.