This research was supported by the Department of Veterans Affairs and the Cultor Co., Ltd., Helsinki, Finland. This work was presented at the Sixth Congress of the International Society for Biomedical Research on Alcoholism, Bristol, United Kingdom, June 21–26, 1992.
Dietary Betaine Promotes Generation of Hepatic S-Adenosylmethionine and Protects the Liver from Ethanol-Induced Fatty Infiltration
Article first published online: 11 APR 2006
Alcoholism: Clinical and Experimental Research
Volume 17, Issue 3, pages 552–555, June 1993
How to Cite
Barak, A. J., Beckenhauer, H. C., Junnila, M. and Tuma, D. J. (1993), Dietary Betaine Promotes Generation of Hepatic S-Adenosylmethionine and Protects the Liver from Ethanol-Induced Fatty Infiltration. Alcoholism: Clinical and Experimental Research, 17: 552–555. doi: 10.1111/j.1530-0277.1993.tb00798.x
- Issue published online: 11 APR 2006
- Article first published online: 11 APR 2006
- Received for publication July 14, 1992: accepted November 9, 1992
- Methionine Synthetase
Previous studies have shown that ethanol feeding to rats alters methionine metabolism by decreasing the activity of methionine synthetase. This is the enzyme that converts homocysteine in the presence of vitamin B12 and N5-methyltetrahydrofolate to methionine. The action of the ethanol results in an increase in the hepatic level of the substrate N5-methyltetrahydrofolate but as an adaptive mechanism, betaine homocysteine methyltransferase, is induced in order to maintain hepatic S-adenosylmethionine at normal levels. Continued ethanol feeding, beyond 2 months, however, produces depressed levels of hepatic S-adenosylmethionine. Because betaine homocysteine methyltransferase is induced in the livers of ethanolfed rats, this study was conducted to determine what effect the feeding of betaine, a substrate of betaine homocysteine methyltransferase, has on methionine metabolism in control and ethanol-fed animals. Control and ethanol-fed rats were given both betainelacking and betaine-containing liquid diets for 4 weeks, and parameters of methionine metabolism were measured. These measurements demonstrated that betaine administration doubled the hepatic levels of S-adenosylmethionine in control animals and increased by 4-fold the levels of hepatic S-adenosylmethionine in the ethanol-fed rats. The ethanol-induced infiltration of triglycerides in the liver was also reduced by the feeding of betaine to the ethanol-fed animals. These results indicate that betaine administration has the capacity to elevate hepatic S-adenosylmethionine and to prevent the ethanol-induced fatty liver.