Article: Evidence that the large neutral amino acid L-valine decreases electrically-evoked release of 5-HT in rat hippocampus in vivo

L-Valine competes with tryptophan for transport into the brain and has previously been shown to decrease brain 5-HT synthesis. In the present study, the effect of L-valine on electrically evoked hippocampal 5-HT release was determined in the anaesthetized rat using microdialysis. In control animals two electrical stimulations of the dorsal raphe nucleus 120 min apart (S1 and S2, respectively) released similar amounts of 5-HT. In contrast, in animals which received L-valine (200 mg/kg) between stimulations, S2 released a significantly smaller amount of 5-HT than did S1, although basal 5-HT release was unchanged. The data demonstrate that L-valine decreases the electrically-evoked release of 5-HT in hippocampus in vivo.

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References

1.

Kennett G, Joseph M . The functional importance of increased brain tryptophan in the serotonergic response to restraint stress. Neuropharmacology. 1981; 20(1):39-43. DOI: 10.1016/0028-3908(81)90039-3. View

2.

Sharp T, Bramwell S, Grahame-Smith D . Release of endogenous 5-hydroxytryptamine in rat ventral hippocampus evoked by electrical stimulation of the dorsal raphe nucleus as detected by microdialysis: sensitivity to tetrodotoxin, calcium and calcium antagonists. Neuroscience. 1990; 39(3):629-37. DOI: 10.1016/0306-4522(90)90247-2. View

3.

Lookingland K, Shannon N, Chapin D, Moore K . Exogenous tryptophan increases synthesis, storage, and intraneuronal metabolism of 5-hydroxytryptamine in the rat hypothalamus. J Neurochem. 1986; 47(1):205-12. DOI: 10.1111/j.1471-4159.1986.tb02851.x. View

4.

Delgado P, Charney D, Price L, Aghajanian G, Landis H, Heninger G . Serotonin function and the mechanism of antidepressant action. Reversal of antidepressant-induced remission by rapid depletion of plasma tryptophan. Arch Gen Psychiatry. 1990; 47(5):411-8. DOI: 10.1001/archpsyc.1990.01810170011002. View

5.

Gessa G, Biggio G, Fadda F, Corsini G, Tagliamonte A . Effect of the oral administration of tryptophan-free amino acid mixtures on serum tryptophan, brain tryptophan and serotonin metabolism. J Neurochem. 1974; 22(5):869-70. DOI: 10.1111/j.1471-4159.1974.tb04308.x. View

6.

Sharp T, Bramwell S, Grahame-Smith D . Effect of acute administration of L-tryptophan on the release of 5-HT in rat hippocampus in relation to serotoninergic neuronal activity: an in vivo microdialysis study. Life Sci. 1992; 50(17):1215-23. DOI: 10.1016/0024-3205(92)90321-f. View

7.

Fernstrom J, Wurtman R . Brain serotonin content: physiological dependence on plasma tryptophan levels. Science. 1971; 173(3992):149-52. DOI: 10.1126/science.173.3992.149. View

8.

Kuhn D, Wolf W, Youdim M . Serotonin neurochemistry revisited: A new look at some old axioms. Neurochem Int. 2010; 8(2):141-54. DOI: 10.1016/0197-0186(86)90157-9. View

9.

Fernstrom J, Faller D . Neutral amino acids in the brain: changes in response to food ingestion. J Neurochem. 1978; 30(6):1531-8. DOI: 10.1111/j.1471-4159.1978.tb10489.x. View

10.

Moir A, Eccleston D . The effects of precursor loading in the cerebral metabolism of 5-hydroxyindoles. J Neurochem. 1968; 15(10):1093-108. DOI: 10.1111/j.1471-4159.1968.tb06827.x. View

11.

Schaechter J, Wurtman R . Serotonin release varies with brain tryptophan levels. Brain Res. 1990; 532(1-2):203-10. DOI: 10.1016/0006-8993(90)91761-5. View

12.

Joseph M, Kennett G . Corticosteroid response to stress depends upon increased tryptophan availability. Psychopharmacology (Berl). 1983; 79(1):79-81. DOI: 10.1007/BF00433020. View

Evidence That the Large Neutral Amino Acid L-valine Decreases Electrically-evoked Release of 5-HT in Rat Hippocampus in Vivo