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Procaine in Cardioplegia: Does It Affect the Endothelial Function?
Author(s) -
Yang Qin,
Liu YaoChun,
Zou Wei,
Yim Anthony PC,
He GuoWei
Publication year - 2002
Publication title -
journal of cardiac surgery
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.428
H-Index - 58
eISSN - 1540-8191
pISSN - 0886-0440
DOI - 10.1046/j.1540-8191.2002.101432.x
Subject(s) - procaine , medicine , bradykinin , coronary arteries , anesthesia , myograph , isometric exercise , vasodilation , cardiology , artery , receptor
Objective: Cardioplegic solutions are widely used in cardiac surgery and hyperkelemia in cardioplegia has been demonstrated to impair the endothelium‐derived hyperpolarizing factor (EDHF)‐mediated endothelial function. The present study examined the effect of procaine in St. Thomas Hospital Cardioplegia on the EDHF‐mediated response in porcine coronary arteries. Methods: Isometric force study: Porcine coronary micro‐arteries were studied in a myograph. Two rings taken from the same artery (diameter 200–450 μm, n = 8 ) were incubated with Kreb's solution as control or Kreb's solution plus procaine (1 mM) at 37 °C for 1 h, respectively. The EDHF‐mediated relaxation was induced by bradykinin (BK, −10 ∼−6.5 log M) in the presence of indomethacin (Indo, 7 μM), NG‐nitro‐L‐arginine (L‐NNA, 300 μM), and hemoglobin (HbO, 20 μM) after U46619‐precontraction (−8 log M). Electrophysiological study: The membrane potential of a single smooth muscle cell in coronary arteries was measured by a microelectrode after superfusion with Kreb's solution or Kreb's containing procaine (1 mM) for 1 h. Results: Procaine had little effect on the resting force of porcine coronary micro‐arteries ( 0.94 ± 0.74 mN vs. 0.67 ± 0.23 mN in control, P > 0.05 ) and did not alter the U46619‐induced precontraction ( 10.7 ± 1.7 mN vs. 12.0 ± 1.7 mN, P > 0.05 ). The BK‐induced, EDHF‐mediated relaxation was increased by the treatment with procaine with the EC50 shifted leftward ( 97.3 ± 0.6% vs. 83.0 ± 5.1% at −7 log M and 99.4 ± 0.6% vs. 96.7 ± 1.6% at −6.5 log M, P < 0.05 ; EC50: −8.57 ± 0.24 vs. −7.92 ± 0.23 log M, P < 0.05 ). Procaine slightly depolarized the smooth muscle cell ( −56.3 ± 1.0 vs. −59.3 ± 0.7 mV, P > 0.05 ) and decreased the BK‐induced hyperpolarization from −70.3 ± 0.4 mV to −68.0 ± 0.8 mV (−7 log M, P < 0.05) and from −72.3 ± 0.7 mV to −68.8 ± 0.8 mV (−6.5 log M, P < 0.01) . Conclusions: In the coronary arteries, procaine has depolarizing effect but it enhances the EDHF‐mediated relaxation. Therefore, addition of procaine in cardioplegia may preserve the EDHF‐mediated endothelial function.