Quantitative Autoradiographic Method for Determination of Regional Rates of Cerebral Protein Synthesis In Vivo

10.3791/58503 ◽  
2019 ◽  
Author(s):  
R. Michelle Saré ◽  
Anita Torossian ◽  
Michael Rosenheck ◽  
Tianjian Huang ◽  
Carolyn Beebe Smith
Keyword(s):  
Protein Synthesis ◽  
Autoradiographic Method ◽  
Cerebral Protein Synthesis

Determination of in vivo protein synthesis in human T lymphocytes

2001 ◽  
Vol 20 (2) ◽  
pp. 181-182 ◽  
Author(s):  
A. JANUSZKIEWICZ ◽  
P. ESSÉN ◽  
M.A. McNURLAN ◽  
O. RINGDÉN ◽  
P.J. GARLICK ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
T Lymphocytes ◽  
Human T Lymphocytes ◽  
In Vivo Protein Synthesis

scholarly journals In vivo Cerebral Protein Synthesis Rates with Leucyl-Transfer RNA Used as a Precursor Pool: Determination of Biochemical Parameters to Structure Tracer Kinetic Models for Positron Emission Tomography

1989 ◽  
Vol 9 (4) ◽  
pp. 429-445 ◽  
Author(s):  
Randy E. Keen ◽  
Jorge R. Barrio ◽  
Sung-Cheng Huang ◽  
Randall A. Hawkins ◽  
Michael E. Phelps
Keyword(s):  
Positron Emission Tomography ◽  
Protein Synthesis ◽  
Bolus Injection ◽  
Emission Tomography ◽  
Precursor Pool ◽  
Leucine Oxidation ◽  
Positron Emission ◽  
Tissue Compartments ◽  
Cerebral Protein Synthesis

Leucine oxidation and incorporation into proteins were examined in the in vivo rat brain to determine rates and compartmentation of these processes for the purpose of structuring mathematical compartmental models for the noninvasive estimation of in vivo human cerebral protein synthesis rates (CPSR) using positron emission tomography (PET). Leucine specific activity (SA) in arterial plasma and intracellular free amino acids, leucyl-tRNA, α-ketoisocaproic acid (KIC), and protein were determined in whole brain of the adult rat during the first 35 min after intravenous bolus injection of l-[1-14C]leucine. Incorporation of leucine into proteins accounted for 90% of total brain radioactivity at 35 min. The lack of [14C]KIC buildup indicates that leucine oxidation in brain is transaminase limited. Characteristic specific activities were maximal between 0 to 2 min after bolus injection with subsequent decline following the pattern: plasma leucine ≥ leucyl-tRNA ≈ KIC > intracellular leucine. The time integral of leucine SA in plasma was about four times that of tissue leucine and twice those of leucyl-tRNA and KIC, indicating the existence of free leucine, leucyl-tRNA, and KIC tissue compartments, communicating directly with plasma, and separate secondary free leucine, leucyl-tRNA, and KIC tissue compartments originating in unlabeled leucine from proteolysis. Therefore, a relatively simple model configuration based on the key assumptions that (a) protein incorporation and catabolism proceed from a precursor pool communicating with the plasma space, and (b) leucine catabolism is transaminase limited is justified for the in vivo assessment of CPSR from exogenous leucine sources using PET in humans.

Microbial protein kinetics for sheep fed with three different hays using15N as marker

2003 ◽  
Vol 2003 ◽  
pp. 160-160
Author(s):  
I. C. S. Bueno ◽  
S. L. S. Cabral Filho ◽  
C. Longo ◽  
A. L. Abdalla
Keyword(s):  
Protein Synthesis ◽  
Protein Level ◽  
Microbial Fermentation ◽  
Microbial Protein ◽  
Protein Kinetics ◽  
Evaluation Systems ◽  
Rumen Degradation ◽  
Protein Supply

Non-degradable dietetic protein supply depends on rumen degradation. Determination of microbial protein synthesized in the rumen as the result of microbial fermentation is important because microbial protein synthesis could be influenced by diet (Dove and Milne, 1994). Several evaluation systems consider the contribution of microbial protein on protein intestinal flow as a constant, based on feed intake. But this approach has presented great variations. The purpose of this work was to determinein vivomicrobial protein kinetics for sheep fed with three protein level hays.

scholarly journals Measurement of Regional Rates of Cerebral Protein Synthesis with L-[1-11C]leucine and PET with Correction for Recycling of Tissue Amino Acids: II. Validation in Rhesus Monkeys

2005 ◽  
Vol 25 (5) ◽  
pp. 629-640 ◽  
Author(s):  
Carolyn Beebe Smith ◽  
Kathleen C Schmidt ◽  
Mei Qin ◽  
Thomas V Burlin ◽  
Michelle P Cook ◽  
...  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Excellent Agreement ◽  
Kinetic Modeling ◽  
Precursor Pool ◽  
Modeling Approach ◽  
Positron Emission ◽  
Arterial Plasma ◽  
Cerebral Protein Synthesis

The confounding effect of recycling of amino acids derived from tissue protein breakdown into the precursor pool for protein synthesis has been an obstacle to adapting in vivo methods for determination of regional rates of cerebral protein synthesis (rCPS) to positron emission tomography (PET). We used a kinetic modeling approach to estimate λ, the fraction of the precursor pool for protein synthesis derived from arterial plasma, and to measure rCPS in three anesthetized adult monkeys dynamically scanned after a bolus injection of L-[1-11C]leucine. In the same animals, λ was directly measured in a steady-state terminal experiment, and values showed excellent agreement with those estimated in the PET studies. In three additional monkeys rCPS was determined with the quantitative autoradiographic L-[1-14C]leucine method. In whole brain and cerebellum, rates of protein synthesis determined with the autoradiographic method were in excellent agreement with those determined with PET, and regional values were in good agreement when differences in spatial resolution of the two methods were taken into account. Low intrasubject variability was found on repeated PET studies. Our results in anesthetized monkey indicate that, by using a kinetic modeling approach to correct for recycling of tissue amino acids, quantitatively accurate and reproducible measurement of rCPS is possible with L-[1-11C]leucine and PET.

scholarly journals Substitution of venous for arterial blood sampling in the determination of regional rates of cerebral protein synthesis with L-[1-11C]leucine PET: A validation study

2018 ◽  
Vol 39 (9) ◽  
pp. 1849-1863 ◽  
Author(s):  
Giampaolo Tomasi ◽  
Mattia Veronese ◽  
Alessandra Bertoldo ◽  
Carolyn B Smith ◽  
Kathleen C Schmidt
Keyword(s):  
Protein Synthesis ◽  
Healthy Volunteers ◽  
Venous Blood ◽  
Blood Sampling ◽  
Adult Males ◽  
Arterial Blood ◽  
Arterial Input Functions ◽  
Pet Scans ◽  
Cerebral Protein Synthesis

We developed and validated a method to estimate input functions for determination of regional rates of cerebral protein synthesis (rCPS) with L-[1-11C]leucine PET without arterial sampling. The method is based on a population-derived input function (PDIF) approach, with venous samples for calibration. Population input functions were constructed from arterial blood data measured in 25 healthy 18–24-year-old males who underwent L-[1-11C]leucine PET scans while awake. To validate the approach, three additional groups of 18–27-year-old males underwent L-[1-11C]leucine PET scans with both arterial and venous blood sampling: 13 awake healthy volunteers, 10 sedated healthy volunteers, and 5 sedated subjects with fragile X syndrome. Rate constants of the L-[1-11C]leucine kinetic model were estimated voxel-wise with measured arterial input functions and with venous-calibrated PDIFs. Venous plasma leucine measurements were used with venous-calibrated PDIFs for rCPS computation. rCPS determined with PDIFs calibrated with 30–60 min venous samples had small errors (RMSE: 4–9%), and no statistically significant differences were found in any group when compared to rCPS determined with arterial input functions. We conclude that in young adult males, PDIFs calibrated with 30–60 min venous samples can be used in place of arterial input functions for determination of rCPS with L-[1-11C]leucine PET.

Determination of Protein Synthesis in Lymphocytes in Vivo after Surgery

1996 ◽  
Vol 91 (1) ◽  
pp. 99-106 ◽  
Author(s):  
Pia Essén ◽  
Margaret A. McNurlan ◽  
Anders Thorell ◽  
Inga Tjäder ◽  
Giuseppe Caso ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Peripheral Blood ◽  
Peripheral Blood Lymphocytes ◽  
Mixed Population ◽  
Synthesis Rate ◽  
Blood Lymphocytes ◽  
Mononuclear Leucocytes

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.

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