Arachidonic acid and prostaglandins enhance potassium-stimulated calcium influx into rat brain synaptosomes.
Exogenous administration of arachidonic acid, prostaglandins PGF2 alpha, PGD2 and PGE2 increased potassium-stimulated uptake of calcium in rat brain synaptosomes from the brain of the rat, but had no effect on the basal uptake of calcium. Arachidonic acid-induced uptake of calcium was mediated by its prostaglandin metabolites, because a cyclooxygenase inhibitor, indomethacin, inhibited the response. L-Type calcium channel blockers, such as verapamil, diltiazem and nimodipine, blocked both KCl- and prostaglandin-enhanced potassium-stimulated influx of calcium in the brain. These results suggest that prostaglandins act as a calcium ionophore, through L-type voltage-sensitive calcium channels.
Kandasamy
S B
SB
Behavioral Sciences Department, Armed Forces Radiobiology Research Institute, Bethesda, Maryland 20814-5145.
Hunt
W A
WA
D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002132:Calcium Radioisotopes; D015237:Dinoprost / Q000494:pharmacology; D015232:Dinoprostone / Q000378:metabolism; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology*; D015230:Prostaglandin D2 / Q000378:metabolism; D011453:Prostaglandins / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism*
D001095:Arachidonic Acids; D002121:Calcium Channel Blockers; D002132:Calcium Radioisotopes; D011453:Prostaglandins; D016718:Arachidonic Acid; D015237:Dinoprost; D015232:Dinoprostone; D011188:Potassium; D015230:Prostaglandin D2; D002118:Calcium; D007213:Indomethacin