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Exercise training‐induced increase in coronary blood flow in Yucatan swine is blunted by hypercholesterolemia
Author(s) -
Sheehy Alexander,
Henderson Kyle K.,
Laughlin M. Harold,
Sturek Michael
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a394
Subject(s) - heart rate , medicine , treadmill , blood pressure , dobutamine , blood flow , cholesterol , rate pressure product , endocrinology , cardiology , hemodynamics
We tested the hypothesis that aerobic exercise training would prevent a high‐fat/cholesterol diet‐induced attenuation of coronary blood flow (CBF) response to a dobutamine stress test in swine. Adult male Yucatan pigs were fed a low‐fat control diet (C) or a high‐fat/cholesterol diet (H; hypercholesterolemic; 46% kcal from fat, 2% cholesterol) for 20 wk. Pigs fed these diets were either exercise trained (X) or remained sedentary (SED); thus, we studied four groups: CSED, CX, HSED, HX. Exercise was treadmill running up to 75 min/day, 5 days/wk for 16 wk. Pigs were instrumented under anesthesia, and a coronary flow wire determined average peak velocity in response to intravenous dobutamine (5μg/kg/min for 5 min) followed by a 5‐min recovery period. Heart rate and blood pressure were continuously recorded. Intravascular ultrasound determined coronary cross sectional area for calculation of CBF (CBF = (1/2) APV*CSA). Rate pressure product (RPP) was used as an assessment of myocardial work, and CBF was standardized to myocardial work (CBF/work). Results: CBF/work ratio of CX was greater than all other groups (p<.05). CBF/work was also higher in the HX compared to CSED and HSED. Surprisingly, the CSED and HSED groups did not differ from each other. Conclusions: Exercise training increased the CBF/work ratio in control and H pigs, relative to sedentary; however, the high fat diet blunted the effects of exercise. Support: NIH HL52490, HL62552.