Effects of nitroglycerin on cardiac function and regional blood flow distribution in conscious dogs

S. F. Vatner, M. Pagani, J. D. Rutherford

Research output: Contribution to journalArticlepeer-review

94 Scopus citations

Abstract

The effects of intravenous infusion of nitroglycerin (NTG), 8 and 32 ug/kg/min. for 7 min., and of sublingual NTG, 1.2 mg, were examined on direct and continuous measurements of systemic, coronary, and regional hemodynamics, left ventricular (LV) dimensions, pressures, and myocardial contractility in conscious dogs. NTG induced sustained reductions in LV dimensions and transient increases in heart rate and dP/dt, and decreases in mean arterial pressure. Initially, NTG increased cardiac output and flows to the coronary, mesenteric, renal, and iliac beds, while systemic and regional vascular resistances fell. Later, cardiac output, cardiac work, and mesenteric and iliac flows fell significantly below control, and significant vasoconstriction in the systemic as well as mesenteric, iliac, and coronary beds was observed at a time when LV end-diastolic dimensions were still significantly reduced. Peripheral vasoconstriction was not observed with systemic NTG in deafferented dogs or when NTG, 1 μg/kg x min, was infused intra-arterially into the iliac bed. Thus, systemic NTG induces a biphasic response consisting of initial arteriolar vasodilation followed by vasoconstriction in the mesenteric, iliac, coronary and systemic beds, which is presumably due to longer lasting effects on preload and to secondary reflex responses to the drug.

Original languageEnglish (US)
Pages (from-to)H244-H252
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume3
Issue number3
DOIs
StatePublished - 1978

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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