PROSTAGLANDINS-F(2-ALPHA) SYNTHESIS IN THE HIPPOCAMPAL MOSSY FIBER SYNAPTOSOMAL PREPARATION .2. EFFECTS OF RECEPTOR ACTIVATION

Mossy fiber nerve endings were isolated from rat hippocampi and used t o determine the effects of receptor activation on the production of pr ostaglandin F2alpha (PGF2alpha). Glutamate and its agonists had no eff ect on PGF2alpha synthesis. Similarly, acetylcholine, gamma-aminobutyr ic acid, histamine and purinergic receptor agonists did not affect PGF 2alpha accumulation in this preparation. However, norepinephrine, sero tonin and dopamine exerted receptor-mediated stimulations of PGF2alpha production. The agonist-evoked increases in PGF2alpha production were attenuated by phospholipase A2 inhibitors, L-type voltage-sensitive C a2+ blockers and a K+ channel activator, but they were insensitive to tetrodotoxin. In addition, a kappa opioid agonist decreased PGF2alpha synthesis in unstimulated and depolarized synaptosomes. It appeared, t herefore, that certain receptor agonists were able to modulate PGF2alp ha synthesis in the hippocampal mossy fiber synaptosomol preparation.