The accumulation of the osmoprotectant glycine betaine from exogenous sources provides a high degree of osmotic tolerance to Bacillus subtilis. We have identified, through functional complementation of an Escherichia coli mutant defective in glycine betaine uptake, a new glycine betaine transport system from B. subtilis. The DNA sequence of a 2,310-bp segment of the cloned region revealed a sin...

The glycine receptors and neurosteroids in spinal cord are both implicated in nociceptive signal processing. However, the modulatory effects of neurosteroid pregnanolone (5beta-pregnan-3alpha-ol-20-one) on native glycine receptors remain unclear. In the present study, we examined the effects of pregnanolone and its three isomers on glycine receptors by using whole-cell patch-clamp technique. Ou...

Excitatory (glutamate) and inhibitory (GABA(A) and glycine) receptor/channels coexist in many neurons. To assess effects of ethanol on the interaction of glutamate and glycine receptors, glycine-induced current (I(Gly)) was recorded by a whole-cell patch-clamp technique from neurons freshly dissociated from the ventral tegmental area of rats. A conditioning prepulse of glutamate (1-3 s, 1 mM) s...

Dietary glycine inhibited hepatocyte proliferation in response to the carcinogen WY-14,643. Since increased cell replication is associated with hepatic cancer caused by WY-14,643, glycine may have anti-cancer properties. Therefore, these experiments were designed to test the hypothesis that dietary glycine would inhibit the growth of tumors arising from B16 melanoma cells implanted subcutaneous...

Glycine and the divalent cation Ca2+ play key roles in regulating the activity of excitatory amino acid NMDA receptor channels. There is accumulating evidence that the concentration of glycine at the synaptic cleft is below a saturated level. We examined the effect of external Ca2+ on NMDA responses in various concentrations of glycine in isolated trigeminal neurons. We found that external Ca2+...

The concentration of transmitter in the synaptic cleft and its clearance time are one of the main determinants of synaptic strength. We estimated the time course of glycine at rat lumbar motoneurons synapses in spinal cord slices by recording synaptic currents in the presence of a low-affinity competitive antagonist at glycine receptors [2-(3-carboxypropyl)-3-amino-6-(4-methoxyphenyl)pyridazini...

Glycine receptors are ligand-gated chloride channels that mediate inhibitory neurotransmission in the adult nervous system. During development, glycine receptor alpha 2 (GlyRalpha2) is expressed in the retina, in the spinal cord, and throughout the brain. Within the cortex, GlyRalpha2 is expressed in immature cells and these receptors have been shown to be active and excitatory. In the developi...

"C n.m.r. spectroscopy has been applied to the investigation of glycine metabolism in tobacco cell cultures (Ashworth & Mettler, 1984) and tobacco protoplasts (Neeman c t ul., 1985). These investigations demonstrated that after prolonged incubation of cells with [2-"C]glycine, the C-2 of glycine was incorporated, in equal proportions. in both the C-2 and C-3 positions of serine; serine was the ...

NMDA receptors are Ca2+-permeable ion channels. The activation of NMDA receptors requires agonist glutamate and co-agonist glycine. Recent evidence indicates that NMDA receptor also has metabotropic function. Here we report that in cultured mouse hippocampal neurons, glycine increases AMPA receptor-mediated currents independent of the channel activity of NMDA receptors and the activation of gly...