During isolation, islets are exposed to warm ischemia. In this study, intraductal administration of oxygenated polymerized, stroma-free hemoglobin-pyridoxalated (Poly SFH-P) was performed to improve O2 delivery. Rat pancreata subjected to 30-min warm ischemia were perfused intraductally with collagenase in oxygenated Poly SFH-P/RPMI or RPMI (control). PO2 was increased by Poly SFH-P (381.7 +/- 35.3 mmHg vs. 202.3 +/- 28.2, p = 0.01) and pH maintained within physiological range (7.4-7.2 vs. 7.1-6.6, p = 0.009). Islet viability (77% +/- 4.6 vs. 63% +/- 4.7, p = 0.04) was improved and apoptosis lower with Poly SFH-P (caspase-3: 34,714 +/- 2167 vs. 45,985 +/- 1382, respectively, p = 0.01). Poly SFH-P improved islet responsiveness to glucose as determined by increased intracellular Ca2+ levels and improved insulin secretion (SI 5.4 +/- 0.1 vs. 3.1 +/- 0.2, p = 0.03). Mitochondrial integrity was improved in Poly SFH-P-treated islets, which showed higher percentage change in membrane potential after glucose stimulation (14.7% +/- 1.8 vs. 9.8 +/- 1.4, respectively, p < 0.05). O2 delivery by Poly SFH-P did not increase oxidative stress (GSH 7.1 +/- 2.9 nm/mg protein for Poly SFH-P vs. 6.8 +/- 2.4 control, p = 0.9) or oxidative injury (MDA 1.8 +/- 0.9 nmol/mg protein vs. 6.2 +/- 2.4, p = 0.19). Time to reach normoglycemia in transplanted diabetic nude mice was shorter (1.8 +/- 0.4 vs. 7 +/- 2.5 days, p = 0.02), and glucose tolerance improved in the Poly SFH-P group (AUC 8106 +/- 590 vs. 10,863 +/- 946, p = 0.03). Oxygenated Poly SFH-P improves islet isolation and transplantation outcomes by preserving mitochondrial integrity.
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http://dx.doi.org/10.1111/j.1600-6143.2006.01551.x | DOI Listing |
Artif Cells Nanomed Biotechnol
February 2013
Artificial Red Cells Group, Waseda Bioscience Research Institute in Singapore (WABIOS), Biopolis, Singapore.
Hemoglobin-based oxygen carriers (HBOCs) have been developed as a transfusion alternative and oxygen therapy. The Hb source is usually outdated donated human blood or cow blood obtained from cattle industries because of its abundance. This study examined the feasibility of using swine Hb ((S)Hb) for preparation of cellular-type HBOCs, hemoglobin-vesicles (HbV).
View Article and Find Full Text PDFCardiology
February 2012
Department of Cardiovascular Surgery, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.
Objectives: The etiology of myocardial ischemia/reperfusion (I/R) injury is multifactorial, but activation of the innate immune system and the resulting inflammatory response are important components of I/R injury. The aim of this study was to investigate the protective effect of a hemoglobin-based oxygen carrier (HBOC) on cold I/R heart and to explore the underlying mechanisms.
Methods: Isolated Sprague-Dawley rat hearts were perfused in the Langendorff mode.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi
October 2009
College of Science and Technology, Tianjin University, Tianjin 300071, China.
Purified hemoglobin was modified with pyridoxal 5-phosphate(PLP) and polymerized with glutaric dialdehyde(GDA) to get the products. By comparison of the physical, chemical and biological properties of different procedures for modification before and after polymerization, there is no significant difference in molecular distribution, methemoglobin(MetHb) concentration, oxygen carrier capacity, P50 and spectra. Furthermore, the procedure of modification after polymerization can save PLP greatly and decrease cost greatly.
View Article and Find Full Text PDFArtif Cells Blood Substit Immobil Biotechnol
October 2009
Tianjin University, China.
A new procedure was developed to obtain high-quality polymerized human hemoglobin by modifying purified hemoglobin with PLP and polymerized with GDA. Comparing polymerized hemoglobin products obtained from different methods, the product from the new procedure has similar physical, chemical, and biological properties in the molecular distribution, methemoglobin concentration, oxygen carrier capacity, P(50) and spectral analysis. Furthermore, the new procedure of modification after polymerization can save PLP greatly, and significantly reduce the cost.
View Article and Find Full Text PDFFree Radic Biol Med
February 2009
Laboratory of Anesthesiology and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu 610041, China.
Ischemia/reperfusion (I/R) injury mainly caused by oxidative stress plays a major role in cardiac damage. The extent of the I/R injury is also an important factor that determines the function of a transplanted heart. This study first examined whether hemoglobin-based oxygen carriers (HBOCs) could protect isolated rat heart from I/R injury and then elucidated the underlying mechanism.
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