TNFalpha stimulated ATP-sensitive potassium channels and attenuated deoxyglucose and Ca uptake of H9c2 cardiomyocytes.
Tumor necrosis factor (TNFalpha) is an inflammatory cytokine that induces programmed cell death in a variety of tissue types, including the heart. Recent experimental data suggest that the TNF expressed within the myocardium in response to environmental injury plays an important role in initiating homeostatic response. The effect of TNFalpha (10-50 ng/mL) was studied on (86)Rb efflux, (3)H-deoxyglucose uptake, or (45)Ca uptake in H9c2 cardiomyocytes. TNFalpha stimulated (86)Rb efflux from cultures, while 2 micro M glibenclamide blocker of ATP-sensitive potassium channels or 20 micro M zvad-fmk caspase inhibitor attenuated this effect. TNFalpha also depressed the stimulatory effect of 80 mM KCl on (45)Ca uptake in the cardiomyocytes. TNFalpha inhibited the stimulatory effect of 100 nM insulin on (3)H-deoxyglucose uptake. Our findings further suggest that TNFalpha mediated adaptive and protective effects in the heart during a brief environmental injury.
El-Ani
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D
Cardiovascular and Hypertension Research Laboratory and Department of Medicine, Institute of Physiologic Hygiene, Wolfson Medical Center, Holon and Tel-Aviv University School of Medicine, Tel-Aviv, Israel. daliae@nvrlab.com
Zimlichman
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R
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D003847:Deoxyglucose / Q000378:metabolism*; D006801:Humans; D007473:Ion Channels / Q000187:drug effects / Q000502:physiology; D008565:Membrane Proteins / Q000187:drug effects / Q000502:physiology*; D032342:Muscle Cells / Q000187:drug effects / Q000502:physiology*; D015221:Potassium Channels; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D012413:Rubidium / Q000493:pharmacokinetics; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D007473:Ion Channels; D008565:Membrane Proteins; D015221:Potassium Channels; D014409:Tumor Necrosis Factor-alpha; C117780:mitochondrial K(ATP) channel; D011189:Potassium Chloride; D003847:Deoxyglucose; D012413:Rubidium; D002118:Calcium