PAF-induced activation of polyphosphoinositide-hydrolyzing phospholipase C in cerebral cortex.
The action of platelet-activating factor (PAF) on phosphoinositide hydrolysis was studied in rat brain slices. PAF produced a significant increase of 32P incorporation into phosphoinositides and phosphatidic acid (PA), in a dose- and time-dependent manner. Concomitantly, an increase of inositol phosphates and diacylglycerol (DAG) production was observed. Both inositol bisphosphate (IP2) and inositol trisphosphate (IP3) were detected as early as 5 s and they returned immediately to basal levels; concomitantly, formation of inositol monophosphate (IP) was detected. These findings demonstrated that PAF causes a rapid hydrolysis of polyphosphoinositides in cerebral cortex by a phospholipase C-dependent mechanism followed by subsequent resynthesis.
Catalán
R E
RE
Departamento de Biología Molecular, Universidad Autónoma de Madrid, Spain.
Martínez
A M
AM
Aragonés
M D
MD
Fernández
I
I
Lombardía
M
M
Miguel
B G
BG
D000818:Animals; D002540:Cerebral Cortex / Q000201:enzymology*; D004075:Diglycerides / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D066298:In Vitro Techniques; D018129:Phosphatidylinositol Phosphates; D010716:Phosphatidylinositols / Q000378:metabolism*; D010972:Platelet Activating Factor / Q000494:pharmacology*; D051381:Rats; D010738:Type C Phospholipases / Q000187:drug effects / Q000378:metabolism*
D004075:Diglycerides; D018129:Phosphatidylinositol Phosphates; D010716:Phosphatidylinositols; D010972:Platelet Activating Factor; D010738:Type C Phospholipases