Intestinal brush border enzymes after short-term mesenteric ischemia.

Area of Science:

• Gastroenterology
• Ischemic injury research
• Biochemistry

Background:

• Intestinal brush border enzymes are crucial for nutrient digestion.
• Mesenteric ischemia can lead to significant gastrointestinal compromise.
• Understanding the impact of ischemia on brush border enzymes is vital for clinical management.

Purpose of the Study:

• To quantify the reduction in specific brush border enzyme activities after superior mesenteric artery (SMA) occlusion.
• To assess changes in enzymatic activity relative to total protein content post-ischemia.

Main Methods:

• Isolated small bowel brush border preparation.
• Measurement of sucrase, trehalase, amino-peptidase, and gamma-glutamyltransferase activity.
• Assessment of total protein content.
• Comparison of enzyme activity and specific activity (U/mg protein) between ischemic and control groups.

Main Results:

• Total activity of sucrase, trehalase, amino-peptidase, and gamma-glutamyltransferase decreased to 35%, 55%, 33%, and 21% of control values, respectively (p<0.001).
• Brush border protein content was reduced to 42% of control.
• Specific activity of gamma-glutamyltransferase was significantly reduced to 48% of control, while other enzymes did not show significant reduction in specific activity.

Conclusions:

• A 45-minute SMA occlusion causes a profound reduction in total brush border enzyme activity in the small intestine.
• While total protein is also reduced, only gamma-glutamyltransferase exhibits a significant decrease in specific activity, indicating a more severe impact on this enzyme's function post-ischemia.