Normalization of hemoglobin-based oxygen carrier-201 induced vasoconstriction: targeting nitric oxide and endothelin.

Hemoglobin-based oxygen carrier (HBOC)-201 is a cell-free modified hemoglobin solution potentially facilitating oxygen uptake and delivery in cardiovascular disorders and hemorrhagic shock. Clinical use has been hampered by vasoconstriction in the systemic and pulmonary beds. Therefore, we aimed to 1) determine the possibility of counteracting HBOC-201-induced pressor effects with either adenosine (ADO) or nitroglycerin (NTG); 2) assess the potential roles of nitric oxide (NO) scavenging, reactive oxygen species (ROS), and endothelin (ET) in mediating the observed vasoconstriction; and 3) compare these effects in resting and exercising swine. Chronically instrumented swine were studied at rest and during exercise after administration of HBOC-201 alone or in combination with ADO. The role of NO was assessed by supplementation with NTG or administration of the eNOS inhibitor Nω-nitro-l-arginine. Alternative vasoactive pathways were investigated via intravenous administration of the ETA/ETB receptor blocker tezosentan or a mixture of ROS scavengers. The systemic and to a lesser extent the pulmonary pressor effects of HBOC-201 could be counteracted by ADO; however, dosage titration was very important to avoid systemic hypotension. Similarly, supplementation of NO with NTG negated the pressor effects but also required titration of the dose. The pressor response to HBOC-201 was reduced after eNOS inhibition and abolished by simultaneous ETA/ETB receptor blockade, while ROS scavenging had no effect. In conclusion, the pressor response to HBOC-201 is mediated by vasoconstriction due to NO scavenging and production of ET. Further research should explore the effect of longer-acting ET receptor blockers to counteract the side effect of hemoglobin-based oxygen carriers.NEW & NOTEWORTHY Hemoglobin-based oxygen carrier (HBOC)-201 can disrupt hemodynamic homeostasis, mimicking some aspects of endothelial dysfunction, resulting in elevated systemic and pulmonary blood pressures. HBOC-201-induced vasoconstriction is mediated by scavenging nitric oxide (NO) and by upregulating endothelin (ET) production. Pressor effects can be prevented by adjuvant treatment with NO donors or direct vasodilators, such as nitroglycerin or adenosine, but dosages must be carefully monitored to avoid hypotension. However, hemodynamic normalization is more easily achieved via administration of an ET receptor blocker.

High-Dose Polymerized Hemoglobin Fails to Alleviate Cardiac Ischemia/Reperfusion Injury due to Induction of Oxidative Damage in Coronary Artery.

Objective. Ischemia/reperfusion (I/R) injury is an unavoidable event for patients in cardiac surgery under cardiopulmonary bypass (CPB). This study was designed to investigate whether glutaraldehyde-polymerized human placenta hemoglobin (PolyPHb), a hemoglobin-based oxygen carrier (HBOC), can protect heart against CPB-induced I/R injury or not and to elucidate the underlying mechanism. Methods and Results. A standard dog CPB model with 2-hour cardiac arrest and 2-hour reperfusion was established. The results demonstrated that a low-dose PolyPHb (0.1%, w/v) provided a significant protection on the I/R heart, whereas the high-dose PolyPHb (3%, w/v) did not exhibit cardioprotective effect, as evidenced by the impaired cardiac function, decreased myocardial oxygen utilization, and elevated enzymes release and pathological changes. Further study indicated that exposure of isolated coronary arteries or human umbilical vein endothelial cells (HUVECs) to a high-dose PolyPHb caused impaired endothelium-dependent relaxation, which was companied with increased reactive oxygen species (ROS) production, reduced superoxide dismutase (SOD) activity, and elevated malonaldehyde (MDA) formation. Consistent with the increased oxidative stress, the NAD(P)H oxidase activity and subunits expression, including gp91(phox), p47(phox), p67(phox), and Nox1, were greatly upregulated. Conclusion. The high-dose PolyPHb fails to protect heart from CPB-induced I/R injury, which was due to overproduction of NAD(P)H oxidase-induced ROS and resultant endothelial dysfunction.

Interaction of recombinant octameric hemoglobin with endothelial cells.

Hemoglobin-based oxygen carriers (HBOCs) may generate oxidative stress, vasoconstriction and inflammation. To reduce these undesirable vasoactive properties, we increased hemoglobin (Hb) molecular size by genetic engineering with octameric Hb, recombinant (r) HbßG83C. We investigate the potential side effects of rHbßG83C on endothelial cells. The rHbßG83C has no impact on cell viability, and induces a huge repression of endothelial nitric oxide synthase gene transcription, a marker of vasomotion. No induction of Intermolecular-Adhesion Molecule 1 and E-selectin (inflammatory markers) transcription was seen. In the presence of rHbßG83C, the transcription of heme oxygenase-1 (oxidative stress marker) is weakly increased compared to the two other HBOCs (references) or Voluven (control). This genetically engineered octameric Hb, based on a human Hb ßG83C mutant, leads to little impact at the level of endothelial cell inflammatory response and thus appears as an interesting molecule for HBOC development.

Impact of acellular hemoglobin-based oxygen carriers on brain apoptosis in rats.

BACKGROUND: Extracellular hemoglobin (Hb)-based oxygen carriers (HBOCs) are under extensive consideration as oxygen therapeutics. Their effects on cellular mechanisms related to apoptosis are of particular interest, because the onset of proapoptotic pathways may give rise to tissue damage. STUDY DESIGN AND METHODS: The objective was to assess whether the properties of the Hb that replaces blood during an isovolemic hemodilution would modulate apoptotic-response mechanisms in rat brain and whether such signaling favors cytoprotection or damage. We exposed rats to exchange transfusion (ET; 50% blood volume and isovolemic replacement with Hextend [negative colloid control], MP4OX [PEGylated HBOC with high oxygen affinity], and ααHb [αα-cross-linked HBOC with low oxygen affinity; n=4-6/group]). Sham rats acted as control. Animals were euthanized at 2, 6, and 12 hours after ET; brain tissue was harvested and processed for analysis. RESULTS: In MP4OX animals, the number of neurons that overexpressed the hypoxia-inducible factor (HIF)-1α was higher than in ααHb, particularly at the early time points. In addition, MP4OX was associated with greater phosphorylation of protein kinase B (Akt), a well-known cytoprotective factor. Indeed, the degree of apoptosis, measured as terminal deoxynucleotidyl transferase-positive neurons and caspase-3 cleavage, ranked in order of MP4OX < Hextend < ααHb. CONCLUSION: Even though both HBOCs showed increased levels of HIF-1α compared to shams or Hextend-treated animals, differences in signaling events resulted in very different outcomes for the two HBOCs. ααHb-treated brain tissue showed significant neuronal damage, measured as apoptosis. This was in stark contrast to the protection seen with MP4OX, apparently due to recruitment of Akt and neuronal specific HIF-1α pathways.

Artificial oxygen carriers based on perfluorodecalin-filled poly(n-butyl-cyanoacrylate) nanocapsules.

Poly(n-butyl-cyanoacrylate)-nanocapsules filled by perfluorodecalin (PFD) are proposed as potential oxygen carriers for blood substitute. The capsule dispersion is prepared via interfacial polymerisation from a PFD emulsion in water which in turn is generated by spontaneous phase separation. The resulting dispersion is capable of carrying approximately 10% of its own volume of gaseous oxygen, which is approximately half of the capacity of human blood. The volumes of the organic solvents and water are varied within a wide range, connected to a change of the capsule radius between 200 and 400 nm. The principal suitability of the capsule dispersion for intravenous application is proven in first physiological experiments. A total amount of 10 ml/kg body weight has been infused into rats, with the dispersion supernatant and a normal saline solution as controls. After the infusion of nanocapsules, the blood pressure as well as the heart rate remains constant on a normal level.

Therapeutic potentials of an artificial oxygen-carrier, liposome-encapsulated hemoglobin, for ischemia/reperfusion-induced cerebral dysfunction in rats.

We performed this study to elucidate whether a newly developed liposome-encapsulated hemoglobin, TRM-645 (TRM), can prevent cerebral dysfunction resulting from acute ischemic stroke when used as an oxygen carrier. Hippocampal long-term potentiation (LTP) in the perforant path-dentate gyrus synapses and anxiety-related behaviors in the elevated plus-maze test were evaluated as indices of cerebral functional outcomes in the rat with two-vessel occlusion (2VO), which was induced by 10-min clamping of bilateral common carotid arteries. Saline or TRM (hemoglobin concentration of 6 g/dl: 2.5 or 5 ml/kg) was administered via the tail vein immediately after ischemic insult. Hippocampal LTP formation was markedly impaired and the open arm durations in the elevated plus-maze decreased significantly 4 days after 2VO, compared to those of sham-operated (control) rats, suggesting the hippocampal synaptic dysfunction and anxiogenic properties in 2VO rats. TRM (5 ml/kg) restored the hippocampal LTP formation and normalized the anxiety-related behavior. TRM also improved the decreased tissue oxygen partial pressure in the 2VO rat hippocampus, possibly due to oxygen delivery to ischemic regions. Liposome-encapsulated hemoglobin TRM might have therapeutic potentials for protecting the brain from neurological complications associated with acute ischemic stroke, as a promising blood substitute for oxygen therapy.

Bone-forming capacity of mesenchymal stromal cells when cultured in the presence of human platelet lysate as substitute for fetal bovine serum.

In tissue engineering, strategies are being developed to repair large bone defects by combining biomaterials and bone marrow-derived multipotent mesenchymal stromal cells (MSCs). For expansion of MSCs under good manufacturing practice conditions, human platelet lysate (PL) can serve as substitute for fetal bovine serum (FBS) in culture media. We compared the in vivo bone-forming capacity of passage 3 MSCs cultured with either PL or FBS for nine different human donors. We also tested the growth kinetics, antigen expression profile, and the multilineage differentiation capacity in vitro of these MSCs. The in vivo bone-forming capacity was determined by seeding culture-expanded MSCs onto biphasic calcium phosphate scaffolds. Hybrid constructs were implanted subcutaneously in nude mice, retrieved after 6 weeks, and analyzed using histomorphometry. PL-supplemented cultures resulted in significantly larger colonies, shorter culture time period, and higher population doublings between P1 and P3 compared to FBS-containing cultures. No differences were observed in antigen expression profiles or differentiation capacities into the osteoblastic, chondrogenic, and adipogenic lineages, qualitatively. In vivo bone formation with PL-supplemented cultures of MSCs was demonstrated in 9/9 donors versus 6/9 for FBS-supplemented cultures. These results warrant the use of PL for ex vivo expansion of human MSCs for bone tissue engineering applications.

Liposome-Encapsulated Hemoglobin, TRM-645: Current Status of the Development and Important Issues for Clinical Application.

Clinical application of artificial oxygen carriers as a substitute for blood transfusion has long been expected to solve some of the problems associated with blood transfusion. Use for oxygen delivery treatment for ischemic disease by oxygen delivery has also been examined. These prospective applications of artificial oxygen carriers are, however, still in development. We have developed liposome-encapsulated hemoglobin (LEH), developmental code TRM-645, using technologies for encapsulation of concentrated hemoglobin (Hb) with high encapsulation efficiency as well as surface modification to achieve stability in circulating blood and a long shelf life. We have confirmed the basic efficacy and safety of TRM-645 as a red blood cell substitute in studies on the efficacy of oxygen delivery in vivo, and the safety of TRM-645 has been studied in some animal species. We are now examining various issues related to clinical studies, including further preclinical studies, management of manufacturing and the quality assurance for the Hb solution and liposome preparations manufactured by the GMP facility.

Impact of oxygenation of bioartificial liver using perfluorocarbon emulsion perftoran on metabolism of human hepatoma C3A cells.

One of the most important challenges in bioartificial liver designed for patients suffering from acute liver failure is oxygenation of cells within the bioreactor. The aim of this study was to evaluate the impact of oxygenation of bioartificial liver using perfluorocarbon (PFC) emulsion on the metabolic activity of hepatic cells in vitro. Mineral fibers coated with collagen type I were used as scaffolds for hepatic cells. Significantly higher total protein synthesis by hepatic C3A cells cultured in the bioreactor for 24 hours, in the group treated with medium supplemented with PFC emulsion, was observed in comparison with medium without PFC. Albumin production increased in the group treated with PFC after 1 hour of perfusion and was continuously, statistically, significantly higher during perfusion then the control group. In conclusion, the use of oxygen carriers, such as the PFC emulsion, can significantly improve synthetic performance of the bioreactor. Mineral fibers coated with extracellular proteins may serve as support for hepatic cells in the bioreactor.

Red cell substitutes.

Oxygen-carrying plasma expanders (blood substitutes) have been sought for over a century. Development of current products is a result of evolution in the understanding of proteins in general, of hemoglobin in particular, and of how cell-free hemoglobin interacts with the control of local blood flow to ensure adequate tissue oxygenation. Hemoglobin-based products are considered in four "generations" corresponding to major improvements. First-generation products consisted of hemoglobin, freed of red cell membranes (stroma-free hemoglobin [SFH]), which was renal toxic and vasoactive. Second-generation products were polymerized with aldehyde reagents to reduce or eliminate the renal toxicity, but the products were heterogeneous and still vasoactive. Third-generation products employed more specific intramolecular crosslinking to eliminate polymerization and promote homogeneity, but they also remained vasoactive. Fourth-generation products are based on a new understanding of the way in which microvascular blood flow is controlled and the influence of O(2) delivery to vascular walls. After more than a century of research, one of these new solutions should find use as an alternative to red cells for transfusion in certain clinical settings.

Vasoactivity of bovine polymerized hemoglobin (HBOC-201) in swine with traumatic hemorrhagic shock with and without brain injury.

BACKGROUND: We previously reported that bovine polymerized hemoglobin (HBOC- 201) improved outcome in swine with hemorrhagic shock (HS) with and without traumatic brain injury (TBI). Herein, we add analyses of blood pressure (BP) responses, associated physiologic data, and HS fluid infusion guidelines. METHODS: HBOC-201 versus standard fluid resuscitation was compared in four anesthetized invasively monitored swine models: moderate controlled HS, severe controlled HS, severe uncontrolled HS (liver injury), and severe uncontrolled HS/TBI (liver/parietal brain injuries). Pigs received fluid for hypotension and tachycardia, and were followed up to 6 (HS alone) or 72 hours (HS/TBI). The change in mean arterial pressure (DeltaMAP) response severity was stratified and analyzed based on infusion number and HS severity, using Student's t and Fisher's exact tests. RESULTS: HBOC-201 vasoactivity resulted in higher MAP in all studies. Among HBOC-201 pigs, DeltaMAP responses were significant for the first two infusions and inversely related to HS severity. Among controls, DeltaMAP responses remained significant through the fourth infusion in controlled HS models, and through the first in severe uncontrolled HS/TBI; none were significant in severe uncontrolled HS. DeltaMAP was higher with HBOC-201 through the first infusion in moderate controlled HS, the fifth in severe uncontrolled HS, and the second in severe uncontrolled HS/TBI; there were no group differences in severe controlled HS. No severe MAP responses occurred. Higher DeltaMAP severity did not impact outcome. Hypotension satisfied fluid reinfusion criteria less consistently than tachycardia. Overall, HBOC-201 improved physiologic parameters and survival without causing hypoperfusion; in severe HS, perfusion improved. CONCLUSIONS: In swine with HS +/- TBI, HBOC-201 had mild to moderate vasoactivity, resulting in significant DeltaMAP responses mainly after initial infusions, no severe/adverse responses, and improved outcome. Our data suggest that use of physiologic parameters (e.g., tachycardia), in addition to hypotension to guide fluid reinfusion during HS resuscitation with HBOC-201, will minimize hypoperfusion risk and maximize potential benefit.

Influence of the hemoglobin solution HBOC-201 on tissue oxygenation in the rat R1H-tumor.

BACKGROUND: HBOC-201 is an ultra purified bovine hemoglobin solution. It has already been used in clinical phase II/III trials for emergency treatments. Animal experiments have shown that HBOC-201 is highly effective in tissue oxygenation. The study was performed in order to assess the potential of low dose HBOC-201 to improve tumor oxygenation. METHODS: 30 rats with a subcutaneously growing rhabdomyosarcoma R1H tumor were randomly assigned either to be ventilated with carbogen (n = 10), or to receive an IV injection of 0.3 g/kg HBOC-201 (n = 10) or a combination of 0.3 g/kg HBOC-201 and carbogen breathing (n = 10). Under general anesthesia the effects of the respective treatment on the tissue oxygen tension (tpO2) of the tumor were determined using a flexible stationary probe at baseline (b) and 15 and 60 min after application of the respective medication. RESULTS: HBOC-201 alone failed to improve tumor tpO2 (b: 1.3 +/- 1.2mmHg; 15min: 1.4 +/- 1 mmHg; 60min: 1 +/- 1 mmHg). In combination with carbogen the mean tpO2 of the tumor raised in comparison to baseline values (b: 3.1 +/- 4.6 mmHg; mmHg; 15min: 8.5 +/- 11*mmHg; 60min: 4.8 +/- 5mmHg; *p < 0.05 vs. b), but this effect was less pronounced than the increase in tpO2 by carbogen alone (b: 3.4 +/- 3.4mmHg; 15min: 9 +/- 10* mmHg; 60 min: 13 +/- 19* mmHg; *p < 0.05 vs. b). CONCLUSION: The application of low dose hemoglobin solution HBOC-201 does not result in improvement of tissue oxygenation in the rat rhabdomyosarcoma R1H.

Resuscitation with a blood substitute causes vasoconstriction without nitric oxide scavenging in a model of arterial hemorrhage.

BACKGROUND: The purpose of this study was to determine if a hemoglobin-based oxygen carrier, HBOC-201 (Hemopure, Biopure Corp), alters endothelial function and nitric oxide physiology when used for hemorrhagic shock. STUDY DESIGN: Female swine (Sus scrofa) underwent catheterization of the femoral, circumflex iliac, and pulmonary arteries. Control animals (n = 3) underwent instrumentation only. Study animals underwent hemorrhage to mean arterial pressure of 30 +/- 5 mmHg, were maintained for 45 minutes, and resuscitated to the baseline mean arterial pressure for 4 hours. Resuscitation fluids included: shed blood (SB) (n = 8), lactated Ringers plus shed blood (LRSB) (n = 8), and HBOC (n = 8). At baseline, 1, and 4 hours after resuscitation, acetylcholine was infused into the proximal iliac artery and endothelial-dependent relaxation was measured with M-mode ultrasonography. Nitric oxide levels were determined using a chemiluminescent assay. RESULTS: HBOC, SB, and LRSB provided equivalent survival and resuscitation as measured by mean arterial pressures (65.3 +/- 2.48 mmHg); pulmonary artery mean pressures (15.8 +/- 0.84 mmHg); and lactate levels (1.22 +/- 0.19 mmol/L). HBOC group animals required the lowest resuscitation volume (SB, 41.5 +/- 3.5 mL/kg; LRSB, 76.4 +/- 1.1 mL/kg, HBOC, 14.6 +/- 2.1 mL/kg, p < 0.001). Response to acetylcholine was normal in the SB and LRSB groups, but the HBOC group had diminished acetylcholine response (29.5% endothelial-dependent relaxation end resuscitation, p < 0.001). Arterial nitric oxide levels did not differ between study groups (p = 0.69). CONCLUSIONS: HBOC might be an alternative resuscitation agent in patients with hemorrhagic shock. Resuscitation with HBOC requires less volume than blood or crystalloid. These data suggest HBOC-201 has a vasoconstrictive effect that cannot be attributed soley to nitric oxide scavenging.

Hemoglobin polymerized with a naturally occurring crosslinking agent as a blood substitute: in vitro and in vivo studies.

A naturally occurring crosslinking agent, genipin, extracted from the fruits of Gardenia jasminoides ELLIS was used by our group to chemically modified biomolecules. Genipin and its related iridoid glucosides have been widely used as an antiphlogistic and cholagogue in herbal medicine. Our previous study showed that the cytotoxicity of genipin is significantly lower than glutaraldehyde. The study was to investigate the feasibility of using genipin to polymerize hemoglobin as a blood substitute. The results indicated that the rate of hemoglobin polymerization by glutaraldehyde was significantly faster than that by genipin and it readily produced polymers with molecular masses greater than 500,000 Da. It was found that the maximum degree of hemoglobin polymerization by genipin was approximately 40% if over-polymerization is to be prevented. With increasing the reaction temperature, hemoglobin concentration, and genipin-to-hemoglobin molar ratio, the duration taken to achieve the maximum degree of hemoglobin polymerization by genipin became significantly shorter. The P50 value of the unmodified hemoglobin was 9 mmHg, while that of the genipin-polymerized PLP-hemoglobin increased to 21 mmHg. It was found in a rat model that the genipin-polymerized PLP-hemoglobin resulted in a longer circulation time than the unmodified hemoglobin. In conclusion, the results of the study indicated that the genipin-polymerized hemoglobin solution has a lower oxygen affinity and a longer vascular retention time than the unmodified hemoglobin solution.

Effect of diaspirin cross-linked haemoglobin (DCLHb) on mean arterial pressure during cardiopulmonary bypass in swine.

Diaspirin cross-linked haemoglobin (DCLHb) is a haemoglobin-based oxygen carrier which had been proposed as a resuscitative solution to replace red cell transfusion in many clinical situations. The present study was designed to evaluate the effect of different volumes of DCLHb 10% (1, 5 and 10 mL kg-1) on the cardiovascular system during cardiopulmonary bypass (CPB), and to determine the effect of DCLHb (18 mL kg-1) when added directly to the CPB prime in anaesthetized swine. DCLHb, when used as a priming solution, induced a significant increase (around 20%) in mean arterial pressure (MAP), which persisted during the entire period of CPB (P < 0.05) as compared with controls. Administration of increasing doses of DCLHb during the time course of CPB resulted in a progressive increase in MAP (P < 0.05), suggesting a linear dose-response relationship. Nicardipine, a calcium channel blocker, returned MAP to baseline. Finally, weaning of CPB was easier in animals that received DCLHb, thereby suggesting a potential protective effect of free haemoglobin in this particular clinical situation.

Enhancement of human osteoblast proliferation and phenotypic expression when cultured in human serum.

Traditionally, culture medium is supplemented with foetal bovine serum (FBS). However, in cultures of osteoblasts intended for human re-implantation, such serum presents potential risks of foreign protein contamination and transmission of viral or prion-related material, if used. We cultured human osteoblasts from 16 patients in 10% autologous human serum, 10% pooled human serum, 10% FBS or 2% Ultroser G. Non-synthetic sera were tested in both heat-treated and non-heat-treated forms. We determined cell growth and osteoblast phenotype. Cell proliferation in all types of human serum was significantly greater than in FBS. This was most marked in heat-treated autologous human serum. Cells cultured in Ultroser G had less proliferation than all other groups. The phenotypic tests showed that cells cultured in human and foetal bovine serum displayed an osteoblast phenotype, with greater protein expression in cells cultured in human serum. We conclude that culture of human osteoblasts in autologous human serum enhances cell proliferation, while maintaining an osteoblast phenotype. These findings have implications for the use of cultured osteoblasts in self-cell therapy. Human osteoblast growth is supported by autologous human serum, which allows re-implantation of cultured cells, while avoiding the risk of foreign protein carry-over with enhancement of cell proliferation.

Effect of alpha-alpha diaspirin crosslinked hemoglobin (DCLHb) on the potency of sodium nitroprusside and nitroglycerine to decrease blood pressure in rats: a dose-response study.

The nitrovasodilators, sodium nitroprusside and nitroglycerine, effect a dose-dependent decrease in mean arterial blood pressure (MABP) by liberating nitric oxide. Alpha-alpha diaspirin crosslinked hemoglobin (DCLHb) is known to bind nitric oxide. We studied the effect of DCLHb on the potency of sodium nitroprusside (n=36) and nitroglycerine (n=36) to decrease MABP in rats which received 1, 10, 100, 1,000, or 10,000 mg/kg of the DCLHb, or normal saline as the Control. Six doses of sodium nitroprusside or nitroglycerine were given to each rat in a systematically varied sequence. For both drugs, in rats given 1, 10, or 100 mg/kg of DCLHb there were no between groups differences in the change in MABP compared to the Control group. For rats that received 1,000 or 10,000 mg/kg of DCLHb, the potency of nitroglycerine and sodium nitroprusside to decrease MABP was less (p<0.05) than the other groups. These data support the hypothesis that small doses of DCLHb effect a minimal change in the potency of nitrovasodilators to reduce blood pressure. However, they suggest that clinically relevant doses of DCLHb attenuate the vasodilatory ability of sodium nitroprusside and nitroglycerine.

[The effect of perftoran on the morphofunctional status of the digestive system organs in experimental duodenal ulcer]. / Vliianie perftorana na morfo-funktsional'noe sostoianie organov pishchevaritel'noi sistemy pri éksperimental'noi iazve dvenadtsatiterstnoi kishki.

The authors studied the effect of perftoran (PF) on the morpho-functional parameters of alimentary system organs (ASO) (liver, pancreas, stomach, duodenum, and small intestine) in rats with experimental chronic acetate duodenal ulcer. Inflammatory-infiltrative and dystrophic changes were found in the ASO tissues which led to activation of the enzymes superoxide dismutase and catalase in their homogenates. PF pharmacotherapy reduces the inflammatory-infiltrative changes in the ASO tissues and normalizes the enzyme systems of antioxidant protection.

[The immunological effects of perftoran]. / Immunologichesie éffekty perftorana.

The effect of perftocarbonic emulsion-perftoran on the course of experimental lipopolysaccharide intoxication was studied in albino mice. Resistance of the animals to the endotoxin reduced 3 days after administration of 10 ml/kg of the preparation and increased 6 days after its administration. The effect of perftoran on the dynamics of some parameters of immunity and nonspecific resistance in CBA mice and guinea pigs was studied in immunodeficiency states induced by injection of 5-fluorouracil, cyclophosphamide, and irradiation. Activation of the phagocytic system occurred 3 days later, and activation of the parameters of cellular and humoral immunity 6 days later.

The role of glutamine, serum and energy factors in growth of enterocyte-like cell lines.

BACKGROUND: Glutamine is routinely added to most cell cultures. Glutamine has been found to be the preferential nutrient to the rapidly replicating intestinal mucosa, but whether this is a metabolic effect or due to other properties of this amino acid is not determined. To study the importance of glutamine on the growth of two enterocyte-like cell lines, the effects of depriving the media or supplementing it with glutamine were assessed in media with different serum and energy supplements. METHODS: CaCo-2 and HT-29 cells were grown in serum-free medium, with fetal bovine or synthetic serum, and with or without glucose or galactose. The glutamine content was varied between 0 and 4 mM. All growth assays were performed in triplicate by counting in a hemocytometer. RESULTS: Both cell lines were dependent of serum factors for growth, but displayed distinct requirements on glutamine supplementation. Glutamine was an obligate supplement with dose-dependent correlation to growth (r = 0.87, p < 0.01) for CaCo-2 cells cultured in synthetic, but not in fetal bovine serum. In HT-29 cells, the correlation between glutamine and growth was significant (r = 0.68, p < 0.05) only in fetal bovine serum in the absence of galactose. CONCLUSION: This study shows that glutamine has different growth stimulating effects on two enterocyte-like cell lines studied. This could reflect different modes of action of glutamine on proliferation and differentiation in an enterocyte cell population.