PGF2 alpha synthesis in isolated cerebellar glomeruli: effects of membrane depolarization, calcium availability and phospholipase activity.
The controlling factors for PGF2 alpha production were assessed in isolated cerebellar glomeruli, since this prostaglandin has been shown to stimulate the release of neurotransmitters from the mossy fiber terminals associated with this synaptic preparation. The metabolism of PGE2 was also examined, in order to determine the specificity of any treatment effects. It was observed that K(+)-dependent membrane depolarization or the activation of voltage-sensitive Na+ channels with veratradine stimulated the production of PGF2 alpha. The syntheses of both prostanoids were dependent on available calcium and were blocked by cyclooxygenase inhibitors. The lipoxygenase inhibitor NDGA also reduced the accumulation of PGE2 and PGF2 alpha. In addition, PGF2 alpha synthesis was stimulated by the phospholipase A2 activator melittin and was reduced due to phospholipase inhibition with dibucaine. These results are consistent with a role for PGF2 alpha in the evoked release of neurotransmitter from cerebellar mossy fiber terminals.
Dorman
R V
RV
Department of Biological Sciences, Kent State University, Ohio 44242.
D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology / Q000502:physiology*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002531:Cerebellum / Q000378:metabolism / Q000502:physiology*; D015237:Dinoprost / Q000096:biosynthesis*; D015232:Dinoprostone / Q000378:metabolism; D007052:Ibuprofen / Q000494:pharmacology; D007213:Indomethacin / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D009637:Masoprocol / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D010740:Phospholipases / Q000378:metabolism*; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D015222:Sodium Channels / Q000187:drug effects / Q000502:physiology; D013569:Synapses / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D014701:Veratridine / Q000494:pharmacology
D002121:Calcium Channel Blockers; D015222:Sodium Channels; D000001:Calcimycin; D014701:Veratridine; D009637:Masoprocol; D015237:Dinoprost; D010740:Phospholipases; D015232:Dinoprostone; D011188:Potassium; D002118:Calcium; D007052:Ibuprofen; D007213:Indomethacin