Action of linoleic acid on phospholipase C activity at the rectal level of the African locust under the control of protein kinase C.
Linoleic acid (18:2n-6), linolenic acid and eicosatrienoic acid stimulated fluid reabsorption in locust rectum. Only 18:2n-6 was able to enhance phospholipase C activity, inositol(1,4,5) trisphosphate production and to increase cytosolic free Ca2+ concentrations in epithelial cells via the opening of L-type Ca2+ channels. These effects resemble those exerted by neuroparsin, an antidiuretic neuronal hormone extracted from the storage lobes of the locust corpora cardiaca. As for neuroparsin, the effects of 18:2n-6 were abolished after pre-treatment with the protein kinase C inhibitor, polymyxin B. The results were consistent with a regulation of neuroparsin-sensitive phospholipase C activity by 18:2n-6 under control of protein kinase C, possibly by increasing membrane fluidity. Cyclooxygenase inhibitors attenuated the effects of 18:2n-6. This demonstrated that the results should be produced via the metabolites of 18:2n-6 HODEs rather than the PUFA itself.
Radallah
D
D
Laboratoire de Neuroendocrinologie, URA CNRS 1138, Université de Bordeaux I, Talence, France.
Nogaro
M
M
Atay-Kadiri
Z
Z
Fournier
B
B
D015126:8,11,14-Eicosatrienoic Acid / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000187:drug effects / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D006110:Grasshoppers; D066298:In Vitro Techniques; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D007301:Insect Hormones / Q000378:metabolism; D007408:Intestinal Absorption / Q000187:drug effects; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000494:pharmacology*; D008297:Male; D008560:Membrane Fluidity / Q000187:drug effects; D011112:Polymyxin B / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D012007:Rectum / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D013050:Spectrometry, Fluorescence; D010738:Type C Phospholipases / Q000378:metabolism*; D017962:alpha-Linolenic Acid / Q000494:pharmacology*
D015220:Calcium Channels; D007301:Insect Hormones; D008041:Linoleic Acids; D017962:alpha-Linolenic Acid; D015544:Inositol 1,4,5-Trisphosphate; D019787:Linoleic Acid; D011493:Protein Kinase C; D010738:Type C Phospholipases; D015126:8,11,14-Eicosatrienoic Acid; D011112:Polymyxin B; D002118:Calcium