Protein kinase C is a mediator of lipopolysaccharide-induced vascular suppression in the rat aorta.
Treatment of vascular tissue with lipopolysaccharide (LPS) in vitro induces hyporesponsiveness to contractile agonists. We investigated whether protein kinase C (PKC) transduces the LPS signal into contractile dysfunction. Rat aortic tissue was incubated .5-18 h with LPS (10 or 30 ng/mL) or alpha- and beta-phorbol 12,13-dibutyrate (PDB, .1 or 1 microM), either alone or combined with cycloheximide (50 microM) or the kinase inhibitors sphingosine (20 microM), H7 (1-(5-isoquinolinylsulfonyl)-2-methyl piperazine, 25 microM), and HA1004 (N-(2-guanidinoethyl)-5-isoquinolinesulfonamide, 25 microM). LPS and beta-PDB induced a sustained translocation of PKC activity from the cytosol to the membrane, an increased protein synthesis-dependent expression of nitric oxide synthase (NOS) activity, and an impaired contractility that could be partially reversed by treatment with the NOS inhibitor N omega-nitro-L-arginine methyl ester. Incubation with alpha-PDB, an inactive isomer of beta-PDB, did not alter any of the tissue functions. Sphingosine blocked LPS- and beta-PDB-induced NOS activity and LPS-induced impairments in tissue contractility and PKC translocation. Incubation with H7 also protected against LPS-induced vasoplegia, while HA1004, used as a negative control for H7, provided little protection against LPS. These data indicate that PKC plays a role as an intracellular mediator of LPS-induced NOS activity and vascular suppression.
McKenna
T M
TM
Septic Shock Research Program, Naval Medical Research Institute, Bethesda, Maryland 20889, USA.
Clegg
J M
JM
Williams
T J
TJ
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000594:Amino Acid Oxidoreductases / Q000378:metabolism; D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000502:physiology; D001120:Arginine / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology; D002462:Cell Membrane / Q000201:enzymology; D002956:Citrulline / Q000378:metabolism; D003513:Cycloheximide / Q000494:pharmacology; D003600:Cytosol / Q000201:enzymology; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D066298:In Vitro Techniques; D007546:Isoquinolines / Q000494:pharmacology; D007700:Kinetics; D008070:Lipopolysaccharides / Q000378:metabolism*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology*; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000502:physiology; D019001:Nitric Oxide Synthase; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013237:Stereoisomerism; D013449:Sulfonamides
D007546:Isoquinolines; D008070:Lipopolysaccharides; D010879:Piperazines; D047428:Protein Kinase Inhibitors; D013449:Sulfonamides; D002956:Citrulline; D009569:Nitric Oxide; D015240:Phorbol 12,13-Dibutyrate; D011189:Potassium Chloride; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; C043204:N-(2-guanidinoethyl)-5-isoquinolinesulfonamide; D001120:Arginine; D003513:Cycloheximide; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; D011494:Protein Kinases; D019331:NG-Nitroarginine Methyl Ester