Glutamate and glycine co-activate while polyamines merely modulate the NMDA receptor complex

A Review of the Actions of D-cycloserine, a Putative Nootropic Agent, at the NMDA Receptor Complex-Associated Glycine Binding Site

“…Most investigators now agree that glycine is an absolute requirement for the activation of the NMDA receptor-associated cation channel, and it has been proposed that glycine and glutamate should be termed coagonists (5,19,(25)(26)(27). However, some investigators have suggested that glycine may be required to activate the NMDA receptor complex only under conditions of low glutamate concentrations (28,29), although most of the current research does not appear to support this theory.…”

A Review of the Actions of D-cycloserine, a Putative Nootropic Agent, at the NMDA Receptor Complex-Associated Glycine Binding Site

“…Most investigators now agree that glycine is an absolute requirement for the activation of the NMDA receptor-associated cation channel, and it has been proposed that glycine and glutamate should be termed coagonists (5,19,(25)(26)(27). However, some investigators have suggested that glycine may be required to activate the NMDA receptor complex only under conditions of low glutamate concentrations (28,29), although most of the current research does not appear to support this theory.…”

Antioxidant Impact of Soft Knotwood Extracts on Human Keratinocytes Shown by NMR Metabolomic Analysis

“…By inhibiting the GlyT1 receptor, sarcosine increases glycine concentration in the cell, which will indirectly potentiate the N-methyl-D-aspartate (NMDA) receptor, for which sarcosine is a coagonist. 40 The ionotropic NMDA receptors are activated by glycine and glutamate and are present in keratinocytes, as demonstrated by Nahm et al 41 In this same publication, it was shown that NMDA activation inhibits the re-epithelialization of keratinocytes during wound healing. It is possible that the observed increase in sarcosine could lead to an increase in glycine in keratinocytes treated with knotwood extracts.…”

“…The regulation of proline availability for collagen biosynthesis is critical for maintaining tissue integrity, for instance during wound healing. Lehmann et al (1991) 40 also found that sarcosine acts as an inhibitor of glycine type I (GlyT1) receptors. By inhibiting the GlyT1 receptor, sarcosine increases glycine concentration in the cell, which will indirectly potentiate the N-methyl-D-aspartate (NMDA) receptor, for which sarcosine is a coagonist.…”

“…Specifically, 6 variables are shared by all treatments (larch, silver fir, spruce and Douglas fir extracts), -Plays a role in establishing the stratum corneum of the epidermis. 39 Sarcosine X X X X Increase -Amino acid, -Involved in glutathione synthesis, 26 -N-methylated derivative of glycine, 26 -Inhibitor of glycine type I (GlyT1) receptors, 40 -Co-agonist of N-methyl-D-aspartate (NMDA) receptor. 41 Taurine X X X Increase -Amino acid derivative, -Involved in glutathione synthesis, 26 -Maintains cell homeostasis via osmoregulation, antioxidant, anti-inflammation activities, 42 -Antiwrinkle activity, 43 -Modulates collagen expression and hyaluronic acid synthesis, 43,44 -Stabilization of cell membrane.…”

Motor actions of eliprodil in the normal and monoamine-depleted mouse: A role in the treatment of Parkinson's disease?

“…The polyamine site controls the NMDA receptor in a regulatory fashion and, unlike the glutamate and glycine binding domains, is not essential for NMDA agonism (Lehmann et al, 1991). Conversely, blockade of the polyamine site does not affect the activity of the glutamate or glycine sites, provided the agonists are in plentiful supply.…”

A Review of the Actions of D-cycloserine, a Putative Nootropic Agent, at the NMDA Receptor Complex-Associated Glycine Binding Site

“…Most investigators now agree that glycine is an absolute requirement for the activation of the NMDA receptor-associated cation channel, and it has been proposed that glycine and glutamate should be termed coagonists (5,19,(25)(26)(27). However, some investigators have suggested that glycine may be required to activate the NMDA receptor complex only under conditions of low glutamate concentrations (28,29), although most of the current research does not appear to support this theory.…”

Antioxidant Impact of Soft Knotwood Extracts on Human Keratinocytes Shown by NMR Metabolomic Analysis

“…By inhibiting the GlyT1 receptor, sarcosine increases glycine concentration in the cell, which will indirectly potentiate the N-methyl-D-aspartate (NMDA) receptor, for which sarcosine is a coagonist. 40 The ionotropic NMDA receptors are activated by glycine and glutamate and are present in keratinocytes, as demonstrated by Nahm et al 41 In this same publication, it was shown that NMDA activation inhibits the re-epithelialization of keratinocytes during wound healing. It is possible that the observed increase in sarcosine could lead to an increase in glycine in keratinocytes treated with knotwood extracts.…”

“…The regulation of proline availability for collagen biosynthesis is critical for maintaining tissue integrity, for instance during wound healing. Lehmann et al (1991) 40 also found that sarcosine acts as an inhibitor of glycine type I (GlyT1) receptors. By inhibiting the GlyT1 receptor, sarcosine increases glycine concentration in the cell, which will indirectly potentiate the N-methyl-D-aspartate (NMDA) receptor, for which sarcosine is a coagonist.…”

“…Specifically, 6 variables are shared by all treatments (larch, silver fir, spruce and Douglas fir extracts), -Plays a role in establishing the stratum corneum of the epidermis. 39 Sarcosine X X X X Increase -Amino acid, -Involved in glutathione synthesis, 26 -N-methylated derivative of glycine, 26 -Inhibitor of glycine type I (GlyT1) receptors, 40 -Co-agonist of N-methyl-D-aspartate (NMDA) receptor. 41 Taurine X X X Increase -Amino acid derivative, -Involved in glutathione synthesis, 26 -Maintains cell homeostasis via osmoregulation, antioxidant, anti-inflammation activities, 42 -Antiwrinkle activity, 43 -Modulates collagen expression and hyaluronic acid synthesis, 43,44 -Stabilization of cell membrane.…”

Motor actions of eliprodil in the normal and monoamine-depleted mouse: A role in the treatment of Parkinson's disease?

“…The polyamine site controls the NMDA receptor in a regulatory fashion and, unlike the glutamate and glycine binding domains, is not essential for NMDA agonism (Lehmann et al, 1991). Conversely, blockade of the polyamine site does not affect the activity of the glutamate or glycine sites, provided the agonists are in plentiful supply.…”

A Review of the Actions of D-cycloserine, a Putative Nootropic Agent, at the NMDA Receptor Complex-Associated Glycine Binding Site

“…Most investigators now agree that glycine is an absolute requirement for the activation of the NMDA receptor-associated cation channel, and it has been proposed that glycine and glutamate should be termed coagonists (5,19,(25)(26)(27). However, some investigators have suggested that glycine may be required to activate the NMDA receptor complex only under conditions of low glutamate concentrations (28,29), although most of the current research does not appear to support this theory.…”

Antioxidant Impact of Soft Knotwood Extracts on Human Keratinocytes Shown by NMR Metabolomic Analysis

“…By inhibiting the GlyT1 receptor, sarcosine increases glycine concentration in the cell, which will indirectly potentiate the N-methyl-D-aspartate (NMDA) receptor, for which sarcosine is a coagonist. 40 The ionotropic NMDA receptors are activated by glycine and glutamate and are present in keratinocytes, as demonstrated by Nahm et al 41 In this same publication, it was shown that NMDA activation inhibits the re-epithelialization of keratinocytes during wound healing. It is possible that the observed increase in sarcosine could lead to an increase in glycine in keratinocytes treated with knotwood extracts.…”

“…The regulation of proline availability for collagen biosynthesis is critical for maintaining tissue integrity, for instance during wound healing. Lehmann et al (1991) 40 also found that sarcosine acts as an inhibitor of glycine type I (GlyT1) receptors. By inhibiting the GlyT1 receptor, sarcosine increases glycine concentration in the cell, which will indirectly potentiate the N-methyl-D-aspartate (NMDA) receptor, for which sarcosine is a coagonist.…”

“…Specifically, 6 variables are shared by all treatments (larch, silver fir, spruce and Douglas fir extracts), -Plays a role in establishing the stratum corneum of the epidermis. 39 Sarcosine X X X X Increase -Amino acid, -Involved in glutathione synthesis, 26 -N-methylated derivative of glycine, 26 -Inhibitor of glycine type I (GlyT1) receptors, 40 -Co-agonist of N-methyl-D-aspartate (NMDA) receptor. 41 Taurine X X X Increase -Amino acid derivative, -Involved in glutathione synthesis, 26 -Maintains cell homeostasis via osmoregulation, antioxidant, anti-inflammation activities, 42 -Antiwrinkle activity, 43 -Modulates collagen expression and hyaluronic acid synthesis, 43,44 -Stabilization of cell membrane.…”

Motor actions of eliprodil in the normal and monoamine-depleted mouse: A role in the treatment of Parkinson's disease?

“…The polyamine site controls the NMDA receptor in a regulatory fashion and, unlike the glutamate and glycine binding domains, is not essential for NMDA agonism (Lehmann et al, 1991). Conversely, blockade of the polyamine site does not affect the activity of the glutamate or glycine sites, provided the agonists are in plentiful supply.…”