Sulfur amino acids in methionine-restricted rats: hyperhomocysteinemia.
OBJECTIVE
Dietary methionine restriction in Fischer-344 rats favorably influences visceral fat mass, insulin sensitivity, metabolic parameters, and longevity. However, little is known about the effects of methionine restriction on serum methionine and its downstream sulfur amino acids. We investigated the serum sulfur amino acid profile of male Fischer-344 rats fed a methionine-restricted diet for 3 mo.


RESULTS
Using tandem mass spectrometry, we observed marked reduction in serum concentrations of methionine, cystathionine, cysteine, and taurine in methionine-restricted rats compared with control (P<0.001) and a 2.5-fold elevation of homocysteine (P<0.001).


CONCLUSIONS
This suggests that homocysteine trans-sulfuration may be inhibited by methionine restriction, and that some of the effects of methionine restriction may be mediated by changes in sulfur amino acids downstream of methionine.
Elshorbagy
Amany K
AK
Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom. amany.elshorbagy@dpag.ox.ac.uk
Valdivia-Garcia
Maria
M
Refsum
Helga
H
Smith
A David
AD
Mattocks
Dwight A L
DA
Perrone
Carmen E
CE
D050154:Adiposity; D000603:Amino Acids, Sulfur / Q000097:blood* / Q000737:chemistry; D000818:Animals; D001835:Body Weight; D003540:Cystathionine / Q000097:blood / Q000737:chemistry; D003545:Cysteine / Q000097:blood / Q000737:chemistry; D004032:Diet / Q000009:adverse effects; D006710:Homocysteine / Q000097:blood / Q000737:chemistry / Q000378:metabolism; D020138:Hyperhomocysteinemia / Q000097:blood* / Q000209:etiology* / Q000378:metabolism; D050152:Intra-Abdominal Fat; D008297:Male; D008715:Methionine / Q000097:blood / Q000737:chemistry / Q000172:deficiency* / Q000378:metabolism*; D011897:Random Allocation; D051381:Rats; D011916:Rats, Inbred F344; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D013654:Taurine / Q000097:blood / Q000737:chemistry
D000603:Amino Acids, Sulfur; D006710:Homocysteine; D013654:Taurine; D003540:Cystathionine; D008715:Methionine; D003545:Cysteine