Role of hydroxyethyl starch in ischemia-reperfusion injury in rat intestinal transplantation.

OBJECTIVE: This study was designed to evaluate the role of 0%, 3%, 6% hydroxyethyl starch (HES) and University of Wisconsin (UW) perfusion and preservation solutions on ischemia-reperfusion injury (IRI) of rat intestinal transplantations, solutions, respectively. MATERIALS AND METHODS: Rats underwent orthotopic intestinal transplantation (Lewis to Lewis) after using perfusion and preservation saline (group l), 3% HES (group 2), 6% HES (group 3), or UW (group 4) solutions. The change in weight was recorded from preoperative to postoperative day (POD) 30. At 30 minutes after reperfusion, we harvested intestinal juice preoperatively as well as at 30 minutes after reperfusion and on POD 1 and 3 when recipients underwent open surgery for maltose absorption tests and sampling. The Park' scores of IRI were evaluated by light microscopy after hematoxylin and eosin (H&E) staining. RESULTS: An increased weight was more evident in group 2 than the other groups, particularly the on POD 1 and POD 3 (P < .05). It was significantly greater than groups 1 and 3 on POD 7 (P < .05). Compared with the other groups, the 30-minute post-reperfusion. Park score and intestinal juice content in group 2 was decreased significantly (P < .01), while in group 3 the Park score was increased, and the maltose absorption level decreased significantly (P < .05). CONCLUSION: Three percent HES solution attenuated IRI in rat intestinal transplantation. High-concentration HES solutions were unfit for intestinal preservation. Thus the adverse effects of UW solution may be attribute at least in part to its high HES, concentration.

Roles of neuronal nitric oxide synthase and inducible nitric oxide synthase in intestinal transplantation of rats.

OBJECTIVE: The study was designed to evaluate the role of neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS) in ischemia-reperfusion injury (IRI) and acute rejection (AR) in rat intestinal transplantation, by administration of nitric oxide inhibitor N(G)-nitro-L-arginine methyl ester (LNAME). MATERIALS AND METHODS: Rats that underwent orthotopic intestinal transplantation were assigned to 2 sets of groups: (1) iso-geneic group (Lewis-Lewis), L-NAME 0 mg/kg/d group (1-1), 4 mg/kg/d (group 1-2), or 8 mg/kg/d (group 1-3) injected intraperitoneally or (2) allogeneic group (Dark Agouti-Lewis), L-NAME 0 mg/kg/d (group 2-1) or 8 mg/kg/d (group 2-2) injected intraperitoneally. We examined survival times, light microscopy as well as maltose absorption tests. The nNOS and iNOS activities were measured by immunohistochemical methods. RESULTS: Histologic examination showed inhibited iNOS activity compared with group l-l, and Park scores decreased significantly in group 1-2 at 30 minutes after reperfusion (1.42 ± 0.38 vs 2.58 ± 0.49, P < .01). Both iNOS and nNOS activities were inhibited and Park scores increased significantly in group 1-3 from 30 minutes to day 3 after reperfusion (P < .0l). nNOS activity decreased and iNOS activity increased among group 2-1 during AR. Compared with group 2-1, iNOS activity was inhibited, progression of AR delayed, and survival significantly prolonged in group 2-2 (10.17 ± 0.98 vs 6.83 ± 0.75, P < .01). CONCLUSION: This study suggested that decreased nNOS and increased iNOS activity both contributed to IRI and AR. More importantly, nNOS more importantly than iNOS activity was closely related to graft structure and function.

Highly efficient dissociation of oxygen from hemoglobin in Tibetan chicken embryos compared with lowland chicken embryos incubated in hypoxia.

Oxygen is one of the critical determinants for normal embryonic and fetal development. In avian embryos, lack of oxygen will lead to high fetal mortality, heteroplasia, and cardiovascular dysfunction. Tibetan chicken is a breed native to Tibet that could survive and keep higher hatchability regardless of negative effects of hypoxia. Generally, adaptive animals in high altitudes are characterized by higher hemoglobin concentrations and oxygen affinity. In the present study, the capacity of oxygen supply in late chick embryo (including d 17, 19, and 21) was compared between Tibetan chicken and a lowland breed, Dwarf White chicken, by determining the hemoglobin concentrations and oxygen equilibrium curves in both hypoxic (13% O(2)) and normoxic (21% O(2)) conditions. The results showed that a higher level of hemoglobin concentration was induced by hypoxia in Tibetan chicken embryos, and the hemoglobin could perform with better cooperativity and deliver oxygen to tissues more easily. Further investigation revealed that the carbonic anhydrase II mRNA in red blood cells of Tibetan chicken was increasingly induced to a higher level in hypoxia than that of the lowland breed. These results suggested that the stronger capacity of oxygen dissociation was an important characteristic of Tibetan chicken embryo to survive in hypoxia and the upregulating mode of carbonic anhydrase II mRNA might assist this dissociation. Therefore, for avian at high altitudes, the efficient dissociation of oxygen might reveal another aspect associated with the hypoxia adaptability.

[Synthesis of Achyranthes bidentata polysaccharide sulfate and its antivirus activity].

Sulfation of Achyranthes bidentata polysaccharide (Abps) with sulfuric acid or sulfur trioxide-pyridine or chlorosulfonic acid-pyridine was studied. A homogeneous sulfation method with good yield of 82.11% was obtained, using chlorosulfonic acid in an excess of pyridine. Sulfated Achyranthes bidentata polysaccharide was obtained as an amorphous sodium salt easily soluble in water. The UV and IR spectrum of Abps sulfate showed absorptions at 208, 268, 286 nm and 1232, 823.6 cm-1 respectively. The sulfur content of the products was found to be 20-22%. The degree of substitution varied from 2.8 to 3.2. It showed that the hydroxy group of Abps was almost completely esterified by chlorosulfonic acid. The Abps sulfate was shown to have high activity as anti-HBsAg and HBeAg. It is also effective on simple herpes virus type-I.