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Updated: Aug 9, 2026
Quantitative Autoradiographic Method for Determination of Regional Rates of Cerebral Protein Synthesis In Vivo
Published on: June 28, 2019
Determination of protein synthesis in lymphocytes in vivo after surgery
P Essén1, M A McNurlan, A Thorell
1Department of Anaesthesiology and Intensive Care, Huddinge University Hospital, Sweden.
Insights
Surgical procedures increase protein synthesis in human peripheral blood mononuclear leukocytes. This in vivo study establishes a new method to measure metabolic activity, revealing a significant increase 24 hours post-surgery.
Area of Science:
- Immunology
- Metabolic research
- Surgical science
Background:
- Previous in vitro studies indicated immune depression post-surgery.
- Interpreting in vitro findings on lymphocyte function is challenging.
- An in vivo method is needed to assess metabolic activity in lymphocytes.
Purpose of the Study:
- To establish an in vivo technique for measuring fractional protein synthesis rate in human peripheral blood lymphocytes.
- To use this technique as an index of metabolic activity.
- To investigate the impact of surgical interventions on lymphocyte protein synthesis.
Main Methods:
- Developed an in vivo stable isotope technique using L-[2H5]phenylalanine.
- Isolated mononuclear leukocytes via density gradient.
- Calculated fractional protein synthesis rate based on isotopic incorporation into cellular protein.
Main Results:
- Demonstrated a linear time course for isotopic incorporation into lymphocytes.
- Observed a significant increase in fractional protein synthesis rate 24 hours after open (49%) and laparoscopic (40%) cholecystectomy.
- This increase was independent of total parenteral nutrition or preoperative glucose infusion.
Conclusions:
- The developed in vivo method accurately assesses lymphocyte metabolic activity.
- Surgical interventions, such as cholecystectomy, stimulate protein synthesis in peripheral mononuclear leukocytes.
- Insulin did not show a similar stimulatory effect on protein synthesis in these cells.
Abstract:
1. The stimulation and depression of peripheral blood lymphocytes has previously been studied in vitro, showing an immune depression postoperatively; however, it is difficult to interpret these in vitro findings. Therefore, an in vivo technique has been established for determination of the fractional protein synthesis rate, as an index of metabolic activity in human peripheral blood lymphocytes, by using a stable isotope technique. 2. The rate of protein synthesis was calculated from the increase in enrichment of L-[2H5]phenylalanine in protein of a mixed population of mononuclear leucocytes, isolated by density gradient, after an intravenous flooding dose of L-[2H5]phenylalanine. A linear time course of isotopic incorporation into the cells was demonstrated. 3. The fractional rate of protein synthesis of a mixed population of mononuclear leucocytes was studied in relation to surgical interventions and to potential modifiers of the response. The fractional synthesis rate increased 24 h after open and laparoscopic cholecystectomy (49 +/- 19% and 40 +/- 14% respectively, P < 0.02), irrespective of postoperative total parenteral nutrition or preoperative glucose infusion. In contrast to surgery, insulin did not stimulate protein synthesis in peripheral mononuclear leucocytes.
