Early effects of Escherichia coli endotoxin infusion on vasopressin-stimulated breakdown and metabolism of inositol lipids in rat hepatocytes.
The turnover of vasopressin-stimulated 32P-phosphoinositides and 32P-phosphatidic acid and accumulation of [2-3H]-inositol phosphates were examined in hepatocytes from rats infused i.v. with saline and E. coli endotoxin for 3 hrs. Within 60s of VP stimulation the decrease in phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate labeling as well as the increased uptake of 32P into phosphatidic acid were similar in both groups. However, at a later time (300s) the 32P-phosphatidylinositol turnover was greatly decreased concomitantly with a higher labeling of phosphatidic acid. The accumulation of [2-3H]-inositol phosphates in ET-cells was significantly decreased both at 30s and 600s after VP addition. The distribution of [2-3H]-inositol labeling accumulated in the different inositol phosphate fractions over the first 30s of VP stimulation showed a tendency to lower accumulation of inositol trisphosphate, and a significantly lower accumulation of inositol bisphosphate simultaneously with a higher labeling of the inositol tetrakisphosphate fraction. These observations reflect an early effect of ET-infusion on VP-stimulated inositol lipid turnover and on the subsequent metabolism of the released inositol phosphates.
D000818:Animals; D004731:Endotoxins / Q000008:administration & dosage*; D004926:Escherichia coli; D007262:Infusions, Intravenous; D007295:Inositol Phosphates / Q000096:biosynthesis / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D008297:Male; D010716:Phosphatidylinositols / Q000378:metabolism; D010761:Phosphorus Radioisotopes; D051381:Rats; D011919:Rats, Inbred Strains; D012965:Sodium Chloride / Q000008:administration & dosage; D013403:Sugar Phosphates / Q000378:metabolism*; D014667:Vasopressins / Q000494:pharmacology*
D004731:Endotoxins; D007295:Inositol Phosphates; D010716:Phosphatidylinositols; D010761:Phosphorus Radioisotopes; D013403:Sugar Phosphates; D014667:Vasopressins; D012965:Sodium Chloride