Brain tyrosine increases after treating with prodrugs: comparison with tyrosine.
After mice had been treated with L-tyrosine, O-phospho-L-tyrosine, L-tyrosine methyl ester or N-acetyl-L-tyrosine, tyrosine was assayed by HPLC coupled with fluorometric detection. O-Phospho-L-tyrosine behaved as a tyrosine prodrug after its hydrolysis by acid and alkaline phosphatases. After the intraperitoneal administration of O-phospho-L-tyrosine or the methyl ester, there was a substantial increase in bioavailability in terms of the effect of tyrosine. The two prodrugs were as powerful as tyrosine following oral administration. N-Acetyl-L-tyrosine was the least effective prodrug tested. The stability, solubility and bioavailability of O-phospho-L-tyrosine are consistent with proposing it for use as a tyrosine prodrug. In addition, it can be used parenterally. The use of a tyrosine aminotransferase inhibitor is necessary for limiting the hepatic breakdown of tyrosine and for increasing its bioavailability.
Topall
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Laboratoire d'Eutonologie, Hôpital Boucicaut, Paris, France.
Laborit
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H
D000818:Animals; D001682:Biological Availability; D001923:Brain Chemistry / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D007274:Injections, Intraperitoneal; D008297:Male; D051379:Mice; D011355:Prodrugs; D013050:Spectrometry, Fluorescence; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology
D011355:Prodrugs; D014443:Tyrosine; C025787:N-acetyltyrosine