Research Article
Endotoxemia Analysis by the Limulus Amoebocyte Lysate Assay in Different Mammal Species Used in Metabolic Studies
F Laugerette*, G Pineau, C Vors and MC Michalski
Université Lyon 1, INSERM U1060, INSA-Lyon, IMBL, CarMeN laboratory, F-69621 Villeurbanne, France
- *Corresponding Author:
- F Laugerette
INRA, UMR1397, Université Lyon 1
INSERM U1060, INSA-Lyon
IMBL, CarMeN laboratory F-69621 Villeurbanne, France
Tel: 33472438112
Fax: +33472438524
E-mail: fabienne.laugerette@univ-lyon1.fr
Received date: June 08, 2015; Accepted date: June 27, 2015; Published date: July 04, 2015
Citation: F Laugerette, G Pineau, C Vors and MC Michalski (2015) Endotoxemia Analysis by the Limulus Amoebocyte Lysate Assay in Different Mammal Species Used in Metabolic Studies. J Anal Bioanal Tech 6:251. doi: 10.4172/2155-9872.1000251
Copyright: © 2015 F Laugerette, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abstract
Introduction: Lipopolysaccharides (LPS) or so-called endotoxins are potent pro-inflammatory compounds. LPS can be present in the bloodstream in case of septic conditions, leading to measure endotoxemia that is the activity of LPS in plasma. Recent research also reveals a low-grade or so-called metabolic endotoxemia associated with metabolic diseases (e.g. obesity, type 2 diabetes, cardiovascular diseases). In this context, research studies use different experimental models, mostly in humans and rodents. Pig is now emerging as a new animal model in nutritional and metabolic studies. However, information is lacking to date about optimal dilution to be used for sample preparation for the Limulus Amebocyte Lysate test, according to species, especially for pig.
Methods: strong>Endotoxemia was measured using the LAL standard reference method. We describe the method of sample preparation and the LAL technique to measure endotoxemia in 4 mammal species: human, mouse, rat and pig.
Results: Plasma dilution is necessary to overcome interferences leading to erroneously low or high results. Optimal dilution to avoid interferences in most samples, while maintaining a satisfactory sensitivity, was found to be at least 1/10 for human vs 1/40 for mice, while much higher dilution was mandatory for pigs, namely 1/200. Altogether, mean plasma endotoxemia in all tested samples using the optimal dilution for each species was 0.73 ± 0.05 EU/mL in humans (n=903), 0.9 ± 0.2 EU/mL in rodents (n=295) and 8.5 ±1.3 EU/mL in pigs (n=186), regardless of fasting or postprandial state and/or type of dietary intervention.
Conclusion: We show that the LAL assay can be used to determine endotoxemia in fasting and postprandial blood samples from different mammal species including pig. Because its detection is made difficult by interference from other plasma constituents, an essential parameter to overcome this difficulty is the dilution factor that depends on the studied species.
