Non-invasive measurement of the haemodynamic effects of inhaled salbutamol, intravenous L-arginine and sublingual nitroglycerin.
OBJECTIVE
To examine the effects of salbutamol and L-arginine, two compounds acting largely on the endothelium, and the endothelium-independent agent nitroglycerin on blood pressure, arterial compliance, cardiac function and vascular resistance.


METHODS
Continuous radial pulse wave analysis, whole-body impedance cardiography, and plethysmographic blood pressure from fingers in the supine position and during head-up tilt were recorded in nine healthy subjects. Data were captured before and after L-arginine (10 mg mg(-1) min(-1)) or saline infusion, salbutamol (400 microg) or placebo inhalation, and sublingual nitroglycerin (0.25 mg) or placebo resoriblet.


RESULTS
The results of all measurements were comparable before drug administration. The effects of inhaled salbutamol were apparent in the supine position: systemic vascular resistance (-9.2 +/- 2.6%) and augmentation index (-4.0 +/- 1.5%) decreased, and heart rate (8.6 +/- 2.5%) and cardiac output (8.8 +/- 3.1%) increased. L-arginine had no clear effects on supine haemodynamics, but during head-up tilt blood pressure was moderately decreased and reduction in aortic reflection time prevented, indicating improved large arterial compliance. Nitroglycerin reduced supine vascular resistance (-6.7 +/- 1.8%) and augmentation index (-7.4 +/- 1.6%), and increased cardiac output (+9.2 +/- 2.7%). During head-up tilt, nitroglycerin increased cardiac output (+10.6 +/- 5.6%) and heart rate (+40 +/- 7.5%), decreased vascular resistance (-7.8 +/- 5.8%) and augmentation index (-18.7 +/- 3.2%), and prevented the decrease in aortic reflection time.


CONCLUSIONS
Inhaled salbutamol predominantly changed supine haemodynamics, whereas the moderate effects of L-arginine were observed during the head-up tilt. In contrast, small doses of nitroglycerin induced major changes in haemodynamics both supine and during the head-up tilt. Altogether, these results emphasize the importance of haemodynamic measurements in both the supine and upright positions.
Tahvanainen
Anna
A
Department of Internal Medicine, University of Tampere, Tampere, Sweden. anna.tahvanainen@uta.fi
Leskinen
Miia
M
Koskela
Jenni
J
Ilveskoski
Erkki
E
Alanko
Juha
J
Kähönen
Mika
M
Kööbi
Tiit
T
Lehtimäki
Lauri
L
Moilanen
Eeva
E
Mustonen
Jukka
J
Pörsti
Ilkka
I
D000328:Adult; D000420:Albuterol / Q000494:pharmacology*; D001120:Arginine / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D002302:Cardiac Output / Q000187:drug effects / Q000502:physiology; D002307:Cardiography, Impedance / Q000187:drug effects; D004333:Drug Administration Routes; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology; D005260:Female; D006439:Hemodynamics / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D008297:Male; D009569:Nitric Oxide; D005996:Nitroglycerin / Q000494:pharmacology*; D016683:Supine Position; D018667:Tilt-Table Test; D014655:Vascular Resistance / Q000187:drug effects / Q000502:physiology; D014665:Vasodilator Agents / Q000494:pharmacology
D014665:Vasodilator Agents; D009569:Nitric Oxide; D001120:Arginine; D005996:Nitroglycerin; D000420:Albuterol