Alterations in the Metabolomics of Sulfur-Containing Substances in Rat Kidneys After Betaine Intake

Betaine;Kidney;Sulfur-amino acid;Transsulfuration reaction;615

약학대학 약학과 ;

University:서울대학교 대학원

关键词: Betaine;    Kidney;    Sulfur-amino acid;    Transsulfuration reaction;    615;   

Others  :  http://s-space.snu.ac.kr/bitstream/10371/133435/1/000000004154.pdf

美国|英语

来源: Seoul National University Open Repository

【 摘 要 】

Previous studies from this lab examined the effect of betaine treatment on liver sulfur-amino acid metabolomics. In this study, 1% of betaine dissolved in drinking water was provided to rats for two weeks in order to measure the changes in the metabolomics of sulfur-containing substances in the kidney. In rats supplemented with betaine, renal methionine level was increased by 42%. However, the activity or protein expression of betaine-homocysteine methyltransferase (BHMT) was not affected by betaine. Methionine synthase, the other enzyme which catalyzes the remethylation of homocysteine to methionine was also unchanged in the betaine treated group. S-Adenosylmethionine (SAM) concentration was increased by betaine feeding, and the protein expression of methionine adenosyltransferase II (MAT II), the type known to be expressed in extrahepatic tissues, increased in the betaine supplemented group. However, S-adenosylhomocysteine (SAH), total homocysteine, and cysteine levels as well as protein expression of cystathionine β-synthase were not affected by betaine treatment. Renal glutathione (GSH) level and the expression of γ-glutamylcysteine synthetase (GCS), the enzyme mediating the production of GSH, were also not changed by betaine supplementation. On the other hand, the rate limiting enzyme of taurine synthesis, cysteine dioxygenase (CDO) was decreased substantially by betaine treatment. However, the activity and protein expression of cysteine sulfinate decarboxylase (CDC) and its product hypotaurine levels increased significantly. These results suggest that despite the negligible expression of BHMT in the kidney, betaine may affect the renal metabolomics of sulfur-containing substances significantly. The increase in hepatic methionine due to betaine treatment appears to account for the increased methionine level in plasma, consequently increasing renal methionine uptake, which serves as the major cause for the changes in the transsulfuration reactions in the rat kidney. Further studies need to be conducted to clarify the physiological and the biochemical significance of these findings.