Thyroid hormones affect the level and activity of nitric oxide synthase in rat cerebral cortex during postnatal development.

The effects of thyroid hormones (TH) on the enzyme level and activity of neuronal nitric oxide synthase (nNOS) were studied in the rat cerebral cortex during postnatal life. As revealed by arginine/citrulline conversion assay and Western blot analysis of the homogenate of the parietal cortex T4 significantly increased nNOS activity and nNOS protein level to 153 +/- 25% and to 178 +/- 20%, respectively. In contrast, 6-n-propyl-2-thyouracil (PTU) decreased nNOS activity and nNOS level to 45 +/- 10% and to 19 +/- 4%, respectively.

Laser treatment of cultured retinal pigment epithelial cells-evaluation of the cellular damage in vitro.

Purpose: Evaluation of the effects of laser photocoagulation on cultured primary retinal pigment epithelial cells.

Methods: Cells were treated by a diode laser (678 nm) with 800 and 1600 mW for 0.186 second.

Cyclic AMP-mediated regulation of striatal glutamate release: interactions of presynaptic ligand- and voltage-gated ion channels and G-protein-coupled receptors.

The presynaptic regulation of striatal glutamate transmission was investigated using D-[3H]aspartate and mouse striatal slices. Functional changes in voltage-dependent and glutamate receptor-gated ion channels were elicited by pharmacologically modifying intracellular cyclic AMP formation via G-protein-coupled receptor stimulation. The kainate (KA)-evoked release was potentiated by the stimulatory G-protein (G(s))-coupled beta-adrenoceptor agonist isoproterenol (ISO) in a concentration-dependent manner.

Regulation of glutamatergic neurotransmission in the striatum by presynaptic adenylyl cyclase-dependent processes.

The aim here was to examine the possible roles of adenylyl cyclase- and protein kinase A (PKA)-dependent processes in ionotropic glutamate receptor (iGluR)-mediated neurotransmission using superfused mouse striatal slices and a non-metabolized L-glutamate analogue, D-[3H]aspartate. The direct and indirect presynaptic modulation of glutamate release and its susceptibility to changes in the intracellular levels of cyclic AMP (cAMP), Ca(2+) and calmodulin (CaM) and in protein phosphorylation was characterized by pharmacological manipulations. The agonists of iGluRs, 2-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) and kainate, stimulated the basal release of D-[3H]aspartate, while N-methyl-D-aspartate (NMDA) was without effect.

Involvement of amino-acid side chains of membrane proteins in the binding of glutathione to pig cerebral cortical membranes.

Glutathione (GSH), a general antioxidant and detoxifying compound, is the most abundant thiol-containing peptide in the central nervous system. It has been earlier shown to regulate the functions of glutamate receptors and to possess specific binding sites in both neurons and glial cells. The possible involvement of disulfide bonds, cysteinyl, arginyl, lysyl, glutamyl, and aspartyl residues in the binding of tritiated GSH to specific sites in pig cerebral cortical synaptic membranes was now studied after covalent modification of membrane proteins.