Distribution of zinc in skeletal muscle and liver tissue in normal and dietary controlled alcoholic rats.

Zinc deficiency is a concomitant of both alcoholism and cirrhosis, as indicated by plasma and tissue measurements in man. The intracellular sites of zinc distribution, the site-specific nature of alcohol/cirrhosis-related depletion, and the alcohol exposure-zinc depletion time function have not been reported. Spague-Dawley rats (16) at 5 to 6 weeks were given normal chow and 20 per cent ethanol as sole water source. Control animals (14) had tap water. In rats killed at 2, 5, 9, and 14 weeks, zinc levels were measured by atomic absorption spectroscopy in plasma (p); muscle tissue (MT), cell sap (MCS) cell sap-free (MCSF), and mitochondria (MM); liver tissue (LT), cell sap (MCS), cell sap-free fraction (LCSF), And mitochondria (LM). Control zinc levels were stable in all tissues over the 14-week study; p = 108, plus or minus 10 mug per 100 ml., MT = 125 plus or minus 18, MCS = 30.3 plus or minus 3, MCSF = 70 plus or minus 6, MM = 209 plus or minus 17, LT = 198 plus or minus 29, LCS = 125 plus or minus 11.0, LCSF = 79.5 plus or minus 11.2, and LM = 291 plus or minus 30 mug per gram of dry tissue. Ethanol-fed rats showed marked decrease in all liver zinc fractions from the earliest (2 weeks) time, with the greatest depletion in LM to 35 per cent of control. MT and p zinc showed monotonic gradual declines at the rate of 3 per cent per week, becoming statistically different from control at 9 weeks in both tissues. Normal weight gain occurred in control animals: alcohol rats gained 52 per cent of control to 5 weeks, and showed no subsequent gain, weighing 62 per cent of control levels at 14 weeks. Liver mitochondria contain the highest zinc concentration, and are most rapidly depleted. MT and p declines follow hepatic zinc loss.