Serum hexosaminidase, host age, and nutritional status

Abstract

Hexosaminidase (HEX), an intestinal lysosomal acid hydrolase, has been suggested to be a useful early marker for both ischemic intestinal injury and recovery. The experimental results analyzing HEX levels in animals of varied ages, nutritional status, and stress levels reported here challenge that principle. In an experiment in which fetal malnutrition was induced by maternal restriction, normal and malnourished, stressed and unstressed 7-day-old pups were analyzed. In no circumstance was intestinal injury documented by either light microscopy or by proton nuclear magnetic resonance relaxation times, but in the 25 animals, serum HEX levels were significantly elevated in the malnourished group (2,108.7 v 1,724.6, P < .001). In an additional experiment, 117, 23-day-old weanling rats were randomized to receive protein restricted 2.5% or 8% chow whereas controls were fed standard 24% chow. Throughout 14 days rats were analyzed for growth (percentage of weight change) and serum HEX concentration. A variable level of serum HEX was seen during subsequent animal growth, but at each assessment values were uniformly higher in the 2.5% diet group, the group that was malnourished and grew less well (4% body weight gain with the 2.5% diet by day 14 v 76% weight gain with the 8% diet v 153% gain with the control 24% diet). (See the Table.) Serum HEX (n Moles Substrate Cleaved per One Half Hour) Dietary Group Day 3 Day 5 Day 7 Day 10 Day 12 Day 14 24% controls 988.6 827.7 1534.6 1164.3 1213.5 678.4 8% protein 1804.8 1283.1 1505.0 1803.7 911.6 803.2 2.5% protein 2087.3 1379.2 2030.8 1754.6 1333.1 1155.1