title: Changes in circadian rhythmicity of liver and serum parameters in rats fed a total parenteral nutrition solution by continuous and discontinuous intravenous or intragastric infusion.
abstract: Circadian rhythms were assessed in rats (224-246 grams) receiving either an intragastric (IG) or intravenous (IV) infusion continuously (C), or IG or IV infusions discontinuously (D) from 0000 to 1400 hours daily. A control group was maintained on a stock diet ad libitum. IV- and IG-fed rats were infused with 50 milliliters per day of a solution containing 25% dextrose and 4.25% amino acids plus vitamins and minerals. After 10 to 11 days, groups of rats were killed from each treatment every 6 hours over a 24-hour period. Results showed that IG feeding promoted better growth and nitrogen retention than IV feeding. Rhythm patterns for liver weight, glycogen, and protein content were similar between D-IG and D-IV infused rats. All groups except the D-IV fed rats exhibited fluctuations of serum insulin. A rhythm was not present for serum glucose in C-IV fed rats and a rhythm was also absent for serum albumin in both C-IV and D-IV fed rats. C-IV feeding increased serum glucose and insulin levels and decreased serum albumin levels in comparison to IG feeding. In comparison to the ad libitum-fed, control rats, C-IV or D-IV or IG infusions led to alterations in liver and serum parameters.
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis*; D001798:Blood Proteins / Q000032:analysis*; D001835:Body Weight; D002404:Catheterization; D002940:Circadian Rhythm; D007263:Infusions, Parenteral; D007328:Insulin / Q000097:blood*; D008099:Liver / Q000378:metabolism*; D008112:Liver Glycogen / Q000378:metabolism; D008297:Male; D009584:Nitrogen / Q000378:metabolism; D010288:Parenteral Nutrition; D010289:Parenteral Nutrition, Total; D011506:Proteins / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012996:Solutions; D013270:Stomach
chemical_list: D001786:Blood Glucose; D001798:Blood Proteins; D007328:Insulin; D008112:Liver Glycogen; D011506:Proteins; D012996:Solutions; D009584:Nitrogen