steroid concentrations in plasma, whole blood and brain effects of saline perfusion to remove blood contamination from brain类固醇在等离子体浓度,全血和脑生理盐水灌注的影响消除大脑血液污染.pdf

Steroid Concentrations in Plasma, Whole Blood and Brain: Effects of Saline Perfusion to Remove Blood Contamination from Brain 1,2 1,3 2 4 1,2 Matthew D. Taves *, Kim L. Schmidt , Ilan M. Ruhr , Katarzyna Kapusta , Nora H. Prior , Kiran K. Soma1,2,3 1 Department of Psychology, University of British Columbia, Vancouver, Canada, 2 Department of Zoology, University of British Columbia, Vancouver, Canada, 3 Graduate Program in Neuroscience, University of British Columbia, Vancouver, Canada, 4 Department of Life Sciences, University of Strasbourg, Strasbourg, France Abstract The brain and other organs locally synthesize steroids. Local synthesis is suggested when steroid levels are higher in tissue than in the circulation. However, measurement of both circulating and tissue steroid levels are subject to methodological considerations. For example, plasma samples are commonly used to estimate circulating steroid levels in whole blood, but steroid levels in plasma and whole blood could differ. In addition, tissue steroid measurements might be affected by blood contamination, which can be addressed experimentally by using saline perfusion to remove blood. In Study 1, we measured corticosterone and testosterone (T) levels in zebra finch (Taeniopygia guttata) plasma, whole blood, and red blood cells (RBC). We also compared corticosterone in plasma, whole blood, and RBC at baseline and after 60 min restraint stress. In Study 2, we quantified corticosterone, dehydroepiandrosterone (DHEA), T, and 17b-estradiol (E2) levels in the brains of sham-perfused or saline-perfused subjects. In Study 1, corticosterone and T concentrations were highest in plasma, si