calcimycin and isospaglumic-acid

The magnesium salt of N acetyl-aspartyl glutamic acid (Naaga), used in ophthalmic allergies, is a synthetic dipeptide analogue of a natural peptide found in mammalian brains. It has been shown in vitro that Naaga inhibits complement activation, mast-cell degranulation and leukotriene anaphylactic release. In order to verify Naaga's action on leukotriene production, we used the macrophage cell line P388D1 activated by calcium ionophore A23187. Leukotriene determination was performed by high-performance liquid chromatography. It was found that Naaga inhibits 15 to 80% macrophage eicosanoid secretion (10(-9) M to 10(-2) M), acting mainly on LTC4-D4-E4 synthesis. Naaga was as potent as the leukotriene inhibitor nordihydroguaiaretic acid and as dexamethasone in this model. This inhibition of leukotriene secretion could partially explain the in-vivo antiallergic effects of Naaga.

Topics: Animals; Calcimycin; Cell Line; Chromatography, High Pressure Liquid; Dexamethasone; Dipeptides; Histamine H1 Antagonists; Leukotrienes; Macrophages; Masoprocol

Depolarization by potassium and veratridine stimulated the release of N-acetyl-L-aspartyl-L-glutamate from crude synaptosomes prepared from the rat mesencephalon and diencephalon. The potassium-evoked release of N-acetyl-L-aspartyl-L-glutamate was calcium-dependent and the stimulatory effect of veratridine was prevented by tetrodotoxin.

Topics: Animals; Brain; Calcimycin; Calcium; Diencephalon; Dipeptides; Male; Mesencephalon; Potassium; Rats; Rats, Inbred Strains; Synaptosomes; Tetrodotoxin; Veratridine