Platelet-activating factor inhibits (Na+,K+) ATPase activity in rat brain.
In the present study, experiments were conducted to determine the effect of platelet-activating factor (PAF) on (Na+,K+)-ATPase in rat cerebral cortex. PAF, but not lysoPAF, inhibited (Na+,K+)ATPase activity, in a dose- and time-dependent manner, 10(-7) to 10(6) M being the most effective dose. These effects were abolished in the presence of PCA-4248, a PAF antagonist, indicating that the PAF effect may be mediated by its specific membrane receptors. Omission of external calcium caused an increase in the basal activity and abolished the PAF effect on (Na+,K+)ATPase. The present study demonstrates that PAF inhibits (Na+,K+)ATPase activity in the cerebral cortex and suggests that PAF released during certain pathological conditions, such as ischemia, may act on ATPase. This could be one possible mechanism of PAF action that needs further attention.
Catalán
R E
RE
Departamento de Biologia Molecular, Universidad Autónoma de Madrid, Spain.
Martínez
A M
AM
Aragonés
M D
MD
Fernández
I
I
Miguel
B G
BG
Calcerrada
M C
MC
Pérez
M J
MJ
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology*; D002118:Calcium / Q000502:physiology; D004095:Dihydropyridines / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D010972:Platelet Activating Factor / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*
D004095:Dihydropyridines; C029271:O-deacetyl platelet activating factor; D010972:Platelet Activating Factor; C066024:PCA 4248; D004533:Egtazic Acid; D000254:Sodium-Potassium-Exchanging ATPase; D002118:Calcium