Abstract

Use of HBOCs has been limited by the side effect of increased mean arterial pressure (MAP). It is thought that HBOCs scavenge NO, leading to decreased [NO], arteriolar vasoconstriction, and increased vascular resistance and arterial pressure. Previous microcirculatory studies investigating effects of HBOC infusion have yielded contradictory results. The aim of this study was to compare responses of tissues with different metabolic activity to HBOC injection. Experiments were conducted in the spinotrapezius muscle or mesentery of anesthetized male Sprague‐Dawley rats. Preparations were loaded with 5 μM DAF‐2DA for 45 min. Cytosolic esterases convert DAF‐2DA to DAF‐2 which reacts with an oxygenated derivative of NO to form highly fluorescent DAF‐2T. The DAF‐2T signal was recorded with a digital CCD camera connected to a Zeiss fluorescence microscope. Vessel diameter, MAP and fluorescence were monitored under control conditions and after bolus i.v. injection of HBOC‐201 in 1, 10 and 100 μM plasma concentrations. HBOC‐201 increased MAP. There was vasoconstriction and an increase in DAF‐2T fluorescence in the spinotrapezius preparation, whereas no vasoconstriction or increase in DAF‐2T fluorescence was observed in the mesentery. These results suggest that metabolically active tissues like skeletal muscle have higher [NO] than less metabolically active tissues such as the mesentery. Support: HL18292.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.