Urinary excretion of nitrogenous and non-nitrogenous compounds in the chronic ethanol-fed rat.
1. The metabolic consequences of chronic ethanol feeding was investigated by assay of urinary metabolites. Male Wistar rats were fed a liquid diet containing 35% of total energy as ethanol or isovolumetric, isocaloric and isonitrogenous amounts of the same diet in which ethanol was substituted by isocaloric glucose (controls). 2. At 6 weeks the entire skeletal muscle mass was reduced by approximately 20%. The urinary excretion of nitrogen, urea and uric acid increased by between 23 and 128%. Urinary creatinine excretion was not significantly altered. 3. Urinary excretion of magnesium was significantly increased by 43%. Urinary excretion of sodium, potassium, calcium and phosphate was increased slightly (i.e. 5-22%), but this change was not statistically significant. 4. Proton n.m.r. spectroscopic analysis showed that ethanol feeding reduced the urinary excretion of citrate and 2-oxoglutarate (by approximately 50%), suggesting decreased citric acid cycle activity. There was an increased excretion of alanine (44%), but excretion of succinate and acetate was not significantly altered. Ethanol in the urine of ethanol-fed rats comprised approximately 2% of total ethanol intake and less than 1% of total energy intake. 5. Lactose was detectable in urine of ethanol-fed rats, but not in control rats, reflecting the reported decreased intestinal lactase activity and increased gut permeability in alcoholics. Urinary galactose excretion decreased by 41%, but relatively large increases in lactate excretion (50%) did not achieve statistical significance. 6. It was concluded that chronic ethanol feeding causes disturbances in whole-body nitrogen homoeostasis and alterations in intermediary metabolism.
Preedy
V R
VR
Department of Clinical Biochemistry, King's College School of Medicine and Dentistry, London, U.K.
Hammond
B
B
Iles
R A
RA
Davies
S E
SE
Gandy
J D
JD
Chalmers
R A
RA
Peters
T J
TJ
D000409:Alanine / Q000652:urine; D000818:Animals; D002952:Citric Acid Cycle / Q000187:drug effects; D000431:Ethanol / Q000494:pharmacology*; D005690:Galactose / Q000652:urine; D006706:Homeostasis / Q000187:drug effects*; D007785:Lactose / Q000652:urine; D008274:Magnesium / Q000652:urine; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009132:Muscles / Q000187:drug effects*; D009584:Nitrogen / Q000652:urine*; D010710:Phosphates / Q000652:urine; D011188:Potassium / Q000652:urine; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000652:urine; D014508:Urea / Q000652:urine; D014527:Uric Acid / Q000652:urine
D010710:Phosphates; D014527:Uric Acid; D000431:Ethanol; D014508:Urea; D012964:Sodium; D008274:Magnesium; D007785:Lactose; D009584:Nitrogen; D000409:Alanine; D011188:Potassium; D005690:Galactose