Selenium reduces hemoglobin-induced epithelial damage to intestinal mucosa.
Modified hemoglobins are being considered as possible "blood substitutes." Experiments were performed to determine whether diaspirin cross-linked hemoglobin (DBBF-Hb) produces epithelial damage and whether this is reduced by selenium (Se). Anesthetized Sprague-Dawley rats, half of which received 2 x 10(-6) g/ml Se, daily for 3 weeks, in their drinking water, were injected with a 5 ml bolus of 10 mg/ml DBBF-Hb. Control animals received saline (5 animals per group). After 30 minutes, the intestine was perfusion-fixed for light and electron microscopy. Eighty villi per rat were assigned an epithelial integrity index (E.I.), ranging from 1 (intact) to 3 (some cell-cell and cell-basement membrane separation). In non-Se rats, E.I. was significantly compromised by DBBF-Hb, compared to HBS-BSA (2.47+/-0.57 (SD) vs. 1.36+/-0.49, p<0.001). In Se rats, neither injection with DBBF-Hb or HBS-BSA caused epithelial damage (1.03+/-0.17 vs. 1.07+/-0.26). Mast cell degranulation per villus (MCD) was measured in 60 villi per rat. In non-Se rats, MCD was significantly greater after DBBF-Hb than after HBS-BSA injection (1.83+/-1.42 vs. 0.2+/-0.4). Supplementary Se did not reduce this effect. In fact, MCD was significantly increased in both sets of rats compared to their non-Se counterparts (3.27+/-2.40 and 1.48+/-1.70 for DBBF-Hb and HBS-BSA, respectively). Since mast cell mediators damage cells, Se must protect the mucosal epithelium in some way.
Baldwin
Ann L
AL
Department of Physiology, College of Medicine, University of Arizona, Tucson 85724-5051, USA.
Wiley
Elizabeth B
EB
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D015550:Cell Degranulation / Q000187:drug effects; D004347:Drug Interactions; D020397:Goblet Cells / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D006454:Hemoglobins / Q000633:toxicity*; D007413:Intestinal Mucosa / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D008407:Mast Cells / Q000378:metabolism / Q000648:ultrastructure; D008854:Microscopy, Electron; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D012643:Selenium / Q000494:pharmacology*
D000975:Antioxidants; D006454:Hemoglobins; D017382:Reactive Oxygen Species; D012643:Selenium