Reference

The glutamate analog a-aminoadipic acid is taken up by astrocytes before exerting its gliotoxic effect in vitro

The glutamate analog a-aminoadipic acid is taken up by astrocytes before exerting its gliotoxic effect in vitro. Huck, Sigismund; Grass, Friedrich; Hoertnagl, Heide (Dep. Neuropharmacol., Univ. Vienna, Vienna A-1090, Austria). J. Neurosci., 4(10), 2650-7 (English) 1984. CODEN: JNRSDS. ISSN: 0270-6474. DOCUMENT TYPE: Journal CA Section: 4 (Toxicology) DL-a-Aminoadipic acid (a-AA) [626-71-1] is accumulated almost selectively by astrocytes in cultures of the dissocd. postnatal mouse cerebellum, presumptive neurons being free of the radiolabel. HPLC anal. of cultures incubated with D- [7620-28-2] or L-a-AA [626-71-1] and DL-[14C]-a-AA autoradiograms conducted in the presence of D- or L-a-AA reveal a stereospecificity of astroglial L-a-AA uptake. Both the uptake of a-AA by astrocytes and a-AA-induced gliotoxicity were Na-dependent. Since 2 mM tetrodotoxin did not prevent the morphol. changes, Na plays its role in a-AA-induced gliotoxicity by mediating the transport of the substance. Thus, a-AA appears to be taken up by the astrocytes before exerting its cytotoxic effect.

The effect of glutamate on the frog semicircular canal

The effect of glutamate on the frog semicircular canal. Valli, Paolo; Zucca, Gianpiero; Prigioni, Ivo; Botta, Laura; Casella, Cesare; Guth, Paul S. (Ist. Fisiol. Gen., Univ. Pavia, Pavia I-27100, Italy). Brain Res., 330(1), 1-9 (English) 1985. CODEN: BRREAP. ISSN: 0006-8993. DOCUMENT TYPE: Journal CA Section: 2 (Mammalian Hormones) Section cross-reference(s): 12 Glutamate (Glu) [56-86-0] has at least 2 sites of action in the frog (Rana esculenta) semicircular canal: the hair cell (presynaptic) and the primary afferent nerve fibers (postsynaptic). Glu's action on the hair cell results in an increased release of the natural transmitter which is responsible for a substantial increase in the frequency of firing in primary afferents. The presynaptic action of Glu is antagonized by D-a-aminoadipate (DaAA) [7620-28-2]. Glu produces a long-lasting depolarization on the afferent nerve fibers which does not by itself elicit any afferent discharge of impulses when the release of the natural transmitter is prevented. Glu-induced nerve depolarization is only partially antagonized by DaAA. The difficulty of reconciling some of the observations made of the effects of Glu in semicircular canals with its presumed role as an afferent transmitter in this organ is discussed, but this role is not definitely rejected.