ARTIFICIAL OXYGEN CARRIER LIPOSOME-ENCAPSULATED HEMOGLOBIN AS THE PLASMA OXYGENIZER

• Published in: International journal of artificial organs 2014-01, Vol.37 (8), p.640-640
• Main Authors: Kawaguchi, A, Ohba, H, Fukumoto, D, Haida, M, Tsukada, H
• Format: Article
• Language: English
• Subjects: Animals; Arteries; Binding; Blood; Hemoglobin; Mathematical analysis; Monkeys; Radioactivity
• ISSN: 0391-3988
• DOI: 10.5301/ijao.5000347

Aim: Since liposome-encapsulated hemoglobin (LEH) has a low specific gravity similar to plasma and different O sub(2)-affinity from that of red blood cell (RBC), it is currently impossible to measure, but calculate/assume O sub(2) contents in the blood of animals infused with LEH. Methods: We examined effects of LEH administration in the blood content of oxygen containing molecules, including CO sub(2), O sub(2) and CO in non-human primates undergoing steady-state gas inhalation study. Plasma and whole blood radioactivity were sequentially monitored in the arterial blood while animals were successively breathing [ super(15)O]-labeled gases ([ super(15)O]CO sub(2), [ super(15)O]O sub(2) and [ super(15)O]CO). The monkeys received base-line measurement, underwent occlusion of the middle cerebral artery, and received LEH with different O sub(2)-affinity and in various doses (n = 18), empty liposome (n = 4) or saline (n = 7) (T2). The [ super(15)O] steady-state respiration tests were repealed immediately following reperfusion (T3) and 3-hours thereafter (T4). Results: While radioactivity of [ super(15)O]CO sub(2) did not change regardless of infusates, [ super(15)O]CO increased in the plasma fraction in a LEH-dose-dependent manner, [ super(15)O]O sub(2) increased in the plasma fraction in an O sub(2)-affinity-dependent manner in the plasma fraction. These levels remained elevated for the following 6 hours, which was parallel to the calculation based on O sub(2) binding characteristics. Conclusions: These results suggest that LEH serves as a plasma oxygenizer to increase O sub(2) content in a unit of blood and may account for benefits of LEH on ischemia/reperfusion of organs and/or tissues.