TY - JOUR
T1 - Coronary and systemic hemodynamic effects of tetramethylpyrazine in the dog
AU - Dai, Xue Zheng
AU - Bache, Robert J
PY - 1985
Y1 - 1985
N2 - The hemodynamic effects of tetramethylpyrazine were examined in 27 anesthetized open chest dogs with electromagnetic flowmeter probes on the left circumflex coronary artery and ascending aorta. Tetramethylpyrazine, 2-15 mg/kg i.v., caused prominent systemic and coronary vasodilation, with a maximum reduction of mean aortic pressure from 92 ± 5 mm Hg during control conditions to 62 ± 7 mm Hg (p < 0.01), a peak increase in cardiac output from 3.0 ± 0.4 to 4.1 ± 0.7 L/min (p < 0.05), and a peak reduction of systemic vascular resistance from 2.450 ± 400 to 1.210 ± 329 dyne·s·cm-5 (p < 0.01). Simultaneously, heart rate increased from 143 ± 9 to 174 ± 8 beats/min (p < 0.01), and maximum left ventricular dP/dt increased from 2.410 ± 120 to 4.020 ± 60 mm Hg/s (p < 0.01). Dose-related increases of coronary blood flow occurred from 37.3 ± 3.7 to a maximum of 74.1 ± 6.6 ml/min (p < 0.01), while mean coronary vascular resistance decreased from 1.770 ± 240 to 700 ± 260 dyne·s·cm-3 (p < 0.01). Myocardial oxygen consumption increased in proportion to the increase in coronary blood flow. Following β-adrenergic blockade with propranolol (1 mg/kg. i.v.), ganglionic blockade with hexamethonium, or catecholamine depletion with reserpine (1.0 mg/kg. i.p.), the systemic and coronary vasodilator effects of tetramethylpyrazine persisted, but the increases in heart rate, maximum left ventricular dP/dt, and myocardial oxygen consumption were markedly attenuated. These data demonstrate that tetramethylpyrazine has potent vasodilating activity in both systemic and coronary circulations. However, the increases in heart rate, maximum left ventricular dP/dt, and myocardial oxygen consumption produced by tetramethylpyrazine appear principally related to reflex activation of the sympathetic nervous system by the drug.
AB - The hemodynamic effects of tetramethylpyrazine were examined in 27 anesthetized open chest dogs with electromagnetic flowmeter probes on the left circumflex coronary artery and ascending aorta. Tetramethylpyrazine, 2-15 mg/kg i.v., caused prominent systemic and coronary vasodilation, with a maximum reduction of mean aortic pressure from 92 ± 5 mm Hg during control conditions to 62 ± 7 mm Hg (p < 0.01), a peak increase in cardiac output from 3.0 ± 0.4 to 4.1 ± 0.7 L/min (p < 0.05), and a peak reduction of systemic vascular resistance from 2.450 ± 400 to 1.210 ± 329 dyne·s·cm-5 (p < 0.01). Simultaneously, heart rate increased from 143 ± 9 to 174 ± 8 beats/min (p < 0.01), and maximum left ventricular dP/dt increased from 2.410 ± 120 to 4.020 ± 60 mm Hg/s (p < 0.01). Dose-related increases of coronary blood flow occurred from 37.3 ± 3.7 to a maximum of 74.1 ± 6.6 ml/min (p < 0.01), while mean coronary vascular resistance decreased from 1.770 ± 240 to 700 ± 260 dyne·s·cm-3 (p < 0.01). Myocardial oxygen consumption increased in proportion to the increase in coronary blood flow. Following β-adrenergic blockade with propranolol (1 mg/kg. i.v.), ganglionic blockade with hexamethonium, or catecholamine depletion with reserpine (1.0 mg/kg. i.p.), the systemic and coronary vasodilator effects of tetramethylpyrazine persisted, but the increases in heart rate, maximum left ventricular dP/dt, and myocardial oxygen consumption were markedly attenuated. These data demonstrate that tetramethylpyrazine has potent vasodilating activity in both systemic and coronary circulations. However, the increases in heart rate, maximum left ventricular dP/dt, and myocardial oxygen consumption produced by tetramethylpyrazine appear principally related to reflex activation of the sympathetic nervous system by the drug.
KW - Blood pressure
KW - Left ventricular afterload
KW - Myocardial blood flow
KW - Myocardial oxygen consumption
KW - Vasodilators
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U2 - 10.1097/00005344-198509000-00005
DO - 10.1097/00005344-198509000-00005
M3 - Article
C2 - 2413290
AN - SCOPUS:0021930455
SN - 0160-2446
VL - 7
SP - 841
EP - 849
JO - Journal of Cardiovascular Pharmacology
JF - Journal of Cardiovascular Pharmacology
IS - 5
ER -