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Enhanced coronary ET‐1 responsiveness and altered K + channel Ca 2+ sensitivity in aortic‐banded miniature swine is attenuated by aerobic interval training
Author(s) -
Emter Craig A.,
Tharp Darla L.,
Ivey Jan R.,
Bowles Douglas K.
Publication year - 2010
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.24.1_supplement.1034.5
Subject(s) - cardiology , medicine , vascular resistance , interval training , heart rate , sed , heart failure , endocrinology , hemodynamics , coronary circulation , basal (medicine) , aerobic exercise , in vivo , blood flow , blood pressure , biology , microbiology and biotechnology , insulin
Altered responsiveness to mediators of vascular tone is observed in several models of congestive heart failure (HF). Recent evidence indicates exercise training is beneficial for patients with HF but the precise intensity and underlying mechanisms are unknown. The purpose of this study was to examine coronary vascular function (CVF) in aortic‐banded (AB) sedentary (HFSED, n=6), AB exercise trained (HFTR, n=5) and control sedentary (SED, n=5) male Yucatan miniature swine. In vivo coronary blood flow (CBF) responses to intracoronary infusion of ET‐1 (1–20 ng/kg/min) and adenosine (ADO; 0.5–5 ug/kg) were measured in the left anterior descending coronary artery (LAD) under anesthesia. Resting CBF was reduced and coronary vascular resistance (CVR) increased (p<0.05) in HFSED animals. The diminished CBF response to ADO in HFSED was attenuated with exercise training and occurred despite unaltered capillarization. ET‐1 induced reductions in conductance (p≤0.05) and increases in resistance (p=0.056) were greater in HFSED vs. SED and HFTR groups. A shift from 200 to 500 nM internal Ca 2+ increased total K + current (whole‐cell voltage clamp) in HFTR and SED but not HFSED LAD smooth muscle cells. In conclusion, interval exercise training attenuates increased basal CVR in AB miniature swine. Increased in vivo ET‐1 and altered K + channel Ca 2+ sensitivity potentially underlie altered CVF. NIH HL093982 & HL52490