Serum hexosaminidase, host age, and nutritional status

Area of Science:

• Biochemistry
• Animal Physiology
• Gastroenterology

Background:

• Hexosaminidase (HEX) is an intestinal lysosomal acid hydrolase.
• HEX has been proposed as an early marker for ischemic intestinal injury and recovery.

Purpose of the Study:

• To investigate the influence of age and nutritional status on serum HEX levels.
• To challenge the principle of HEX as a reliable early marker for ischemic intestinal injury.

Main Methods:

• Fetal malnutrition induced by maternal restriction in 7-day-old pups.
• Protein restriction (2.5% or 8% chow) in 117, 23-day-old weanling rats for 14 days.
• Analysis of serum HEX levels, light microscopy, and proton nuclear magnetic resonance relaxation times.

Main Results:

• Serum HEX levels were significantly elevated in malnourished pups (2,108.7 vs 1,724.6, P < .001) without documented intestinal injury.
• Malnourished rats on a 2.5% protein diet exhibited higher serum HEX levels throughout growth compared to controls.
• Growth rates varied significantly: 4% (2.5% diet), 76% (8% diet), and 153% (24% control diet) weight gain by day 14.

Conclusions:

• Serum HEX levels demonstrate marked variability influenced by subject age and nutritional status.
• These factors (age, nutrition) are highly variable in patients with potential ischemic intestinal injury.
• The utility of HEX as a sole early marker for ischemic intestinal injury requires re-evaluation due to confounding variables.