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Effects of enoximone on peripheral and central chemoreflex responses in humans.
- Source :
-
American journal of physiology. Heart and circulatory physiology [Am J Physiol Heart Circ Physiol] 2008 Jan; Vol. 294 (1), pp. H322-9. Date of Electronic Publication: 2007 Oct 26. - Publication Year :
- 2008
-
Abstract
- cAMP plays an important role in peripheral chemoreflex function in animals. We tested the hypothesis that the phosphodiesterase inhibitor and inotropic medication enoximone increases peripheral chemoreflex function in humans. In a single-blind, randomized, placebo-controlled crossover study of 15 men, we measured ventilatory, muscle sympathetic nerve activity, and hemodynamic responses to 5 min of isocapnic hypoxia, 5 min of hyperoxic hypercapnia, and 3 min of isometric handgrip exercise, separated by 1 wk, with enoximone and placebo administration. Enoximone increased cardiac output by 120 +/- 3.7% from baseline (P < 0.001); it also increased the ventilatory response to acute hypoxia [13.6 +/- 1 vs. 11.2 +/- 0.7 l/min at 5 min of hypoxia, P = 0.03 vs. placebo (by ANOVA)]. Despite a larger minute ventilation and a smaller decrease in O(2) desaturation (83 +/- 1 vs. 79 +/- 2%, P = 0.003), the muscle sympathetic nerve response to hypoxia was similar between enoximone and placebo (123 +/- 6 and 117 +/- 6%, respectively, P = 0.28). In multivariate regression analyses, enoximone enhanced the ventilatory (P < 0.001) and sympathetic responses to isocapnic hypoxia. Hyperoxic hypercapnia and isometric handgrip responses were not different between enoximone and placebo (P = 0.13). Enoximone increases modestly the chemoreflex responses to isocapnic hypoxia. Moreover, this effect is specific for the peripheral chemoreflex, inasmuch as central chemoreflex and isometric handgrip responses were not altered by enoximone.
- Subjects :
- Adult
Apnea physiopathology
Cardiac Output drug effects
Central Nervous System physiopathology
Chemoreceptor Cells physiopathology
Cross-Over Studies
Enoximone administration & dosage
Hand Strength
Hemodynamics drug effects
Humans
Infusions, Intravenous
Male
Muscle, Skeletal drug effects
Muscle, Skeletal innervation
Peripheral Nervous System physiopathology
Phosphodiesterase Inhibitors administration & dosage
Pulmonary Ventilation drug effects
Single-Blind Method
Sympathetic Nervous System drug effects
Time Factors
Central Nervous System drug effects
Chemoreceptor Cells drug effects
Enoximone pharmacology
Hypercapnia physiopathology
Hyperoxia physiopathology
Hypoxia physiopathology
Peripheral Nervous System drug effects
Phosphodiesterase Inhibitors pharmacology
Reflex drug effects
Subjects
Details
- Language :
- English
- ISSN :
- 0363-6135
- Volume :
- 294
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- American journal of physiology. Heart and circulatory physiology
- Publication Type :
- Academic Journal
- Accession number :
- 17965284
- Full Text :
- https://doi.org/10.1152/ajpheart.00790.2007