Blood sampling methodology is crucial for precise measurement of plasma catecholamines concentrations in mice.
Epinephrine (E) and norepinephrine (NE) play a major role in regulating metabolism and cardiovascular physiology. Both are secreted in response to stress and their measurement in plasma allows the study of sympathoadrenal function. Several studies investigating sympathoadrenal physiology are conducted using mice. Review of the literature revealed that basal mouse NE and E plasma concentrations range within 4-140 nM depending on the blood sampling method. Such variability doesn't allow study comparison and may conceal catecholamine variations in response to stress. Therefore, our aim was to determine a reliable sampling method to measure mouse plasma catecholamine concentrations. Results showed that arterial catheterization is the most accurate sampling method: E and NE basal levels were similar to those found in humans (1.1+/-0.3 nM and 4.1+/-0.5 nM, respectively). Retro-orbital bleeding led to analogous results. On the contrary, decapitation was stressful for mice and consequently NE and E concentrations were high (24.6+/-2.7 nM and 27.3+/-3.8 nM, respectively). These different bleeding methods were compared in terms of their ability to detect sympathoadrenal system stimulation (cold-pressure test). With catheter and retro-orbital samplings the expected increase in NE and E levels was easily perceived. In contrast, with decapitation no significant change in E was detected. In conclusion, arterial-catheter and retro-orbital blood sampling methods appear to be the most accurate procedures for studying the sympathetic nervous system in mice in both unstressed and stressed conditions.
Grouzmann
Eric
E
Division of Clinical Pharmacology and Toxicology, Centre Hospitalier Universitaire Vaudois, 1011 Lausanne, Switzerland. Eric.Grouzmann@chuv.hospvd.ch
Cavadas
Claudia
C
Grand
Daniela
D
Moratel
Martine
M
Aubert
Jean-François
JF
Brunner
Hans R
HR
Mazzolai
Lucia
L
D000818:Animals; D001158:Arteries; D001794:Blood Pressure; D001800:Blood Specimen Collection / Q000009:adverse effects / Q000379:methods*; D002395:Catecholamines / Q000097:blood*; D002404:Catheterization; D003080:Cold Temperature; D004837:Epinephrine / Q000097:blood; D005260:Female; D006339:Heart Rate; D008297:Male; D051379:Mice; D009915:Orbit / Q000098:blood supply; D009994:Osmolar Concentration; D013312:Stress, Physiological / Q000097:blood / Q000209:etiology / Q000503:physiopathology
D002395:Catecholamines; D004837:Epinephrine