Milrinone attenuates arteriolar vasoconstriction and capillary perfusion deficits on endotoxemic hamsters

• Published in: PloS one 2015-02, Vol.10 (2), p.e0117004-e0117004
• Main Authors: de Miranda, Marcos Lopes, Pereira, Sandra J, Santos, Ana O M T, Villela, Nivaldo R, Kraemer-Aguiar, Luiz Guilherme, Bouskela, Eliete
• Format: Article
• Language: English
• Subjects: Adrenergic alpha-Agonists - therapeutic use; Analysis; Animals; Anti-inflammatory agents; Blood pressure; Capillaries - drug effects; Capillary pressure; Catheters; Drugs; E coli; Endotoxemia; Endotoxemia - complications; Endotoxemia - drug therapy; Endotoxemia - microbiology; Endotoxemia - physiopathology; Experiments; Hamsters; Hematology; Hemodynamics; Hemodynamics - drug effects; Implantation; Inflammation; Inflammatory response; Intensive care; Internal medicine; Intravenous administration; Laboratory animals; Lipopolysaccharides; Male; Mesocricetus; Microcirculation - drug effects; Microscopy; Microvasculature; Milrinone; Milrinone - therapeutic use; Norepinephrine; Norepinephrine - therapeutic use; Pediatrics; Perfusion; Polyethylene; Quantitative analysis; Rodents; Sepsis; Skin; Survival; Vasoconstriction; Vasoconstriction - drug effects; Vasodilator Agents - therapeutic use
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0117004

Apart from its inotropic property, milrinone has vasodilator, anti-inflammatory and antithrombotic effects that could assist in the reversal of septic microcirculatory changes. This paper investigates the effects of milrinone on endotoxemia-related microcirculatory changes and compares them to those observed with the use of norepinephrine. After skinfold chamber implantation procedures and endotoxemia induction by intravenous Escherichia coli lipopolysaccharide administration (2 mg.kg-1), male golden Syrian hamsters were treated with two regimens of intravenous milrinone (0.25 or 0.5 μg.kg-1.min-1). Intravital microscopy of skinfold chamber preparations allowed quantitative analysis of microvascular variables. Macro-hemodynamic, biochemical, and hematological parameters and survival rate were also analyzed. Endotoxemic non-treated animals, endotoxemic animals treated with norepinephrine (0.2 μg.kg-1.min-1), and non-endotoxemic hamsters served as controls. Milrinone (0.5 μg.kg-1.min-1) was effective in reducing lipopolysaccharide-induced arteriolar vasoconstriction, capillary perfusion deficits, and inflammatory response, and in increasing survival. Norepinephrine treated animals showed the best mean arterial pressure levels but the worst functional capillary density values among all endotoxemic groups. Our data suggests that milrinone yielded protective effects on endotoxemic animals' microcirculation, showed anti-inflammatory properties, and improved survival. Norepinephrine did not recruit the microcirculation nor demonstrated anti-inflammatory effects.