title: Betaine feeding prevents the blood alcohol cycle in rats fed alcohol continuously for 1 month using the rat intragastric tube feeding model.
abstract: BACKGROUND
  Blood alcohol levels (BAL) cycle up and down over a 7-8 day period when ethanol is fed continuously for one month in the intragastric tube feeding rat model (ITFRM) of alcoholic liver disease. The cycling phenomenon is due to an alternating increase and decrease in the metabolic rate. Recently, we found that S-adenosyl-methionine (SAMe) fed with alcohol prevented the BAL cycle.
  
  
  METHODS
  Using the ITFRM we fed rats betaine (2 g/kg/day) with ethanol for 1 month and recorded the daily 24 h urine ethanol level (UAL) to measure the BAL cycle. UAL is equivalent to BAL because of the constant ethanol infusion. Liver histology, steatosis and BAL were measured terminally after 1 month of treatment. Microarray analysis was done on the mRNA extracted from the liver to determine the effects of betaine and alcohol on changes in gene expression.
  
  
  RESULTS
  Betaine fed with ethanol completely prevented the BAL cycle similar to SAMe. Betaine also significantly reduced the BAL compared to ethanol fed rats without betaine. This was also observed when SAMe was fed with ethanol. The mechanism involved in both cases is that SAMe is required for the conversion of epinephrine from norepinephrine by phenylethanolamine methyltransferase (PNMT). Epinephrine is 5 to 10 fold more potent than norepinephrine in increasing the metabolic rate. The increase in the metabolic rate generates NAD, permitting ADH to increase the oxidation of alcohol. NAD is the rate limiting factor in oxidation of alcohol by alcohol dehydrogenase (ADH). This explains how SAMe and betaine prevented the cycle. Microarray analysis showed that betaine feeding prevented the up regulation of a large number of genes including TLR2/4, Il-1b, Jax3, Sirt3, Fas, Ifngr1, Tgfgr2, Tnfrsf21, Lbp and Stat 3 which could explain how betaine prevented fatty liver.
  
  
  CONCLUSIONS
  Betaine feeding lowers the BAL and prevents the BAL cycle by increasing the metabolic rate. This increases the rate of ethanol elimination by generating NAD.
authors.affiliation: Harbor-UCLA Medical Center, Torrance, CA 90509, USA.
authors.forename: J
authors.initials: J
authors.lastname: Li
authors.forename: X M
authors.initials: XM
authors.lastname: Li
authors.forename: M
authors.initials: M
authors.lastname: Caudill
authors.forename: O
authors.initials: O
authors.lastname: Malysheva
authors.forename: F
authors.initials: F
authors.lastname: Bardag-Gorce
authors.forename: J
authors.initials: J
authors.lastname: Oliva
authors.forename: B A
authors.initials: BA
authors.lastname: French
authors.forename: E
authors.initials: E
authors.lastname: Gorce
authors.forename: K
authors.initials: K
authors.lastname: Morgan
authors.forename: E
authors.initials: E
authors.lastname: Kathirvel
authors.forename: T
authors.initials: T
authors.lastname: Morgan
authors.forename: S W
authors.initials: SW
authors.lastname: French
mesh_terms: D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D001622:Betaine / Q000008:administration & dosage / Q000494:pharmacology*; D001835:Body Weight / Q000187:drug effects; D002794:Choline / Q000097:blood; D004750:Enteral Nutrition; D000431:Ethanol / Q000008:administration & dosage* / Q000097:blood* / Q000652:urine; D005247:Feeding Behavior / Q000187:drug effects*; D005786:Gene Expression Regulation / Q000187:drug effects; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D023421:Models, Animal; D051381:Rats; D017208:Rats, Wistar; D012521:Sarcosine / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D000431:Ethanol; D001622:Betaine; C025138:dimethylglycine; D000410:Alanine Transaminase; D002794:Choline; D012521:Sarcosine