The Presynaptic Effects of Arachidonic Acid and Prostaglandin E2 at the Frog Neuromuscular Junction

Abstract

Arachidonic acid and prostaglandin E2 decreased the frequency of miniature endplate potentials with producing any changes in the their amplitude-time parameters. Arachidonic acid and prostaglandin E2 decreased the quantum composition of endplate currents and the amplitude of the third phase of the nerve ending response, which reflects currents though potential-dependent K+ channels. A perineural method was used to demonstrate that arachidonic acid and prostaglandin E2 suppressed the nerve ending Ca2+ current. The cyclooxygenase blocker indomethacin increased neurotransmitter secretion and decreased the third phase of the nerve ending response. The effects of arachidonic acid and prostaglandin E2 on evoked neurotransmitter release were not seen in the presence of indomethacin, while the third phase of the response continued to show a reduction. It is suggested that prostaglandin E2 mediates the effects of arachidonic acid on spontaneous and evoked neurotransmitter secretion, Ca2+ currents, and Ca2+ -dependent K+ currents. In addition, arachidonic acid and prostaglandin E2 had their own effects on potential-dependent K+ currents in nerve endings.

Binary mixtures of diclofenac with paracetamol, ibuprofen, naproxen, and acetylsalicylic acid and these pharmaceuticals in isolated form induce oxidative stress on Hyalella azteca

“…These eicosanoids act as autocrine and paracrine messengers and, in invertebrate species such as H. azteca, as important mediators during reproduction and in the immune system (Deridovich and Reunova 1993;Stanley 2000;Fortier et al 2008). Prostaglandins are also involved in neurotransmission and the transport of ions across cell membranes (Arkhipova et al 2005). The final result of these actions in the present study might have been inhibition of neurotransmission evidenced by H. azteca immobilization.…”

Oxidative stress induced in Hyalella azteca by an effluent from a NSAID-manufacturing plant in Mexico

“…These eicosanoids act as autocrine and paracrine messengers and, in invertebrate species such as H. azteca, as important mediators during reproduction and in the immune system (Stanley 2000;Fortier et al 2008). Prostaglandins are also involved in neurotransmission and the transport of ions across cell membranes (Arkhipova et al 2005). The final result of these actions in the present study might have been inhibition of neurotransmission evidenced by H. azteca immobilization.…”

Ecotoxicogenomic assessment of diclofenac toxicity in soil

“…Prostaglandins are involved in many physiological processes, for instance pain mediation, neurotransmission, regulation of systemic circulation vascular permeability, ion transport across cell membranes and the function of the renals (Arkhipova et al, 2006). At both diclofenac exposure concentrations, no significant transcriptional effect was observed related to inhibition of cyclooxygenase or prostaglandin metabolism.…”