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Eyenga P, Roussel D, Rey B, Ndille P, Teulier L, Eyenga F, Romestaing C, Morel J, Gueguen-Chaignon V, Sheu SS. Mechanical ventilation preserves diaphragm mitochondrial function in a rat sepsis model. Intensive Care Med Exp 2021; 9:19. [PMID: 33825987 PMCID: PMC8025065 DOI: 10.1186/s40635-021-00384-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 03/24/2021] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND To describe the effect of mechanical ventilation on diaphragm mitochondrial oxygen consumption, ATP production, reactive oxygen species (ROS) generation, and cytochrome c oxidase activity and content, and their relationship to diaphragm strength in an experimental model of sepsis. METHODS A cecal ligation and puncture (CLP) protocol was performed in 12 rats while 12 controls underwent sham operation. Half of the rats in each group were paralyzed and mechanically ventilated. We performed blood gas analysis and lactic acid assays 6 h after surgery. Afterwards, we measured diaphragm strength and mitochondrial oxygen consumption, ATP and ROS generation, and cytochrome c oxidase activity. We also measured malondialdehyde (MDA) content as an index of lipid peroxidation, and mRNA expression of the proinflammatory interleukin-1β (IL-1β) in diaphragms. RESULTS CLP rats showed severe hypotension, metabolic acidosis, and upregulation of diaphragm IL-1β mRNA expression. Compared to sham controls, spontaneously breathing CLP rats showed lower diaphragm force and increased susceptibility to fatigue, along with depressed mitochondrial oxygen consumption and ATP production and cytochrome c oxidase activity. These rats also showed increased mitochondrial ROS generation and MDA content. Mechanical ventilation markedly restored mitochondrial oxygen consumption and ATP production in CLP rats; lowered mitochondrial ROS production by the complex 3; and preserved cytochrome c oxidase activity. CONCLUSION In an experimental model of sepsis, early initiation of mechanical ventilation restores diaphragm mitochondrial function.
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Affiliation(s)
- P. Eyenga
- Center for Translational Medicine, Department of Medicine, Thomas Jefferson University, Philadelphia, PA 19107 USA
- Université Claude Bernard Lyon 1, 69008 Lyon, France
| | - D. Roussel
- Laboratoire d’Ecologie des Hydrosystèmes Naturels et Anthropisés, UMR 5023, Université de Lyon, Université Lyon1, CNRS, 69622 Villeurbanne, France
| | - B. Rey
- Laboratoire de Biométrie et Biologie Evolutive, UMR 5558, Université de Lyon, Université Lyon1, CNRS, 69622 Villeurbanne, France
| | - P. Ndille
- Département de Chirurgie, Centre Hospitalier D’Ebomé, Kribi, Cameroun
| | - L. Teulier
- Laboratoire d’Ecologie des Hydrosystèmes Naturels et Anthropisés, UMR 5023, Université de Lyon, Université Lyon1, CNRS, 69622 Villeurbanne, France
| | - F. Eyenga
- Université Claude Bernard Lyon 1, 69008 Lyon, France
| | - C. Romestaing
- Laboratoire d’Ecologie des Hydrosystèmes Naturels et Anthropisés, UMR 5023, Université de Lyon, Université Lyon1, CNRS, 69622 Villeurbanne, France
| | - J. Morel
- Service de réanimation chirurgicale, CHU de Saint Etienne, 42000 Saint Etienne, France
| | - V. Gueguen-Chaignon
- Protein Science Facility, ENS de Lyon, Inserm, US8, SFR Biosciences UMS 3444 - CNRS Université Claude Bernard Lyon 1, 69007 Lyon, France
| | - S-S. Sheu
- Center for Translational Medicine, Department of Medicine, Thomas Jefferson University, Philadelphia, PA 19107 USA
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Peineau N, Mongo KG, Le Guennec JY, Garnier D, Argibay JA. Alteration of the L-type calcium current in guinea-pig single ventricular myocytes by heptaminol hydrochloride. Br J Pharmacol 1992; 107:104-8. [PMID: 1422567 PMCID: PMC1907608 DOI: 10.1111/j.1476-5381.1992.tb14470.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
1. The effects of heptaminol on calcium current amplitude and characteristics were studied in single ventricular myocytes of guinea-pig by use of the whole cell configuration of the patch clamp technique. 2. A concentration-dependent decrease in ICa amplitude was observed. At heptaminol concentration as low as 10(-6) M, this effect was observed in only two cells (n = 6). At 10(-5) M the reduction of ICa was of 30 +/- 15% (n = 11). 3. The current recovery from inactivation at -40 mV holding potential (HP) seemed less sensitive to perfusion with heptaminol (greater than 10(-6) M). However, at -80 mV HP the overshoot of the recovery curve was decreased by heptaminol. 4. Both at -40 mV and -80 mV HP, heptaminol (10(-5) M) significantly increased the steady state inactivation of ICa. 5. As previously proposed by others to explain the effects of membrane active substances, the effects of heptaminol may result from alterations in cell membrane properties and possibly from an increase in intracellular free calcium ion concentration.
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Affiliation(s)
- N Peineau
- Laboratoire d'électrophysiologie, et de pharmacologie cellulaires, Faculté des Sciences, Tours, France
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