Blood flow measurements in rats using four color microspheres during blockade of different vasopressor systems

Blood flow measurements in rats using four color microspheres during blockade of different vasopressor systems

Author De Angelis, Katia Google Scholar
Gama, V. M. Google Scholar
Farah, VAM Google Scholar
Irigoyen, Maria Claudia Autor UNIFESP Google Scholar
Institution Universidade de São Paulo (USP)
Universidade Federal de São Paulo (UNIFESP)
Univ Santo Amaro
Univ Sao Judas Tadeu
Abstract The use of colored microspheres to adequately evaluate blood flow chancres under different circumstances in the same rat has been validated with a maximum of three different colors due to methodological limitations. the aim of the present study was to validate the use of four different colors measuring four repeated blood flow. changes in the same rat to assess the role of vasopressor systems in. controlling arterial pressure (AP). Red (150,000), white (200,000)), yellow (150,000), and blue (200,000) colored microspheres were infused into the left ventricle of 6 male Wistar rats 1) at rest and 2) after vasopressin (aAVP, 10 mug/kg, iv), 3) renin-angiotensin (losartan, 10 ms/kg iv), and 4) sympathetic system blockade (hexamethonium., 20 mg/kg, iv) to determine blood flow changes. AP was recorded and processed with a data acquisition system (1-kHz sampling frequency). Blood flow changes were quantified by spectrophotometry absorption peaks for colored microsphere components in the tissues evaluated. Administration of aAVP and losartan slightly reduced the AP (-5.7 +/- 0.5 and -7.8 +/- 1.2 mmHg, respectively), while hexamethonium induced a 52 +/- 3 mmHg fall in AP. the aAVP injection increased blood flow in lungs (78%), liver (117%) and skeletal muscle (>150%), while losartan administration enhanced blood flow in heart (126%), lungs (100%), kidneys (80%), and gastrocnemius (75%) and soleus (94%) muscles. Hexamethonium administration reduced only kidney blood flow (50%). in conclusion, four types of colored microspheres can be used to perform four repeated blood flow measurements in the same rat detecting small alterations such as changes in tissues with low blood flow.
Keywords colored microspheres
arterial pressure
sympathetic system
renin-angiotensin
vasopressin
local blood flow measurement
Language English
Date 2005-01-01
Published in Brazilian Journal of Medical and Biological Research. São Paulo: Assoc Bras Divulg Cientifica, v. 38, n. 1, p. 119-125, 2005.
ISSN 0100-879X (Sherpa/Romeo, impact factor)
Publisher Assoc Bras Divulg Cientifica
Extent 119-125
Origin http://dx.doi.org/10.1590/S0100-879X2005000100018
Access rights Open access Open Access
Type Article
Web of Science ID WOS:000226663600018
SciELO ID S0100-879X2005000100018 (statistics in SciELO)
URI http://repositorio.unifesp.br/handle/11600/28067

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