Immuno-metabolic effects of lysozyme in acute blood loss

Lysozyme injections (1 or 5 mg/kg) produced marked immunomodulating, antioxidant and hepatoprotective effects in Wistar rats which had lost much blood (3% body mass). Lysozyme action is mediated by heavy erythrocytes and glass-adherent splenocytic cytokines the production of which is provoked by these erythrocytes.     

Regulatory activity of Kupffer cells in acute blood loss

The scavenger function of Kupffer cells and the erythropoietinlike, granulocyte-macrophage colony-stimulating, and leukocyte- and lymphocyte-stimulating activities of extracts of Kupffer cells obtained before and at different times after acute massive blood loss were experimentally evaluated on mice. Extracts of Kupffer cells from normal mice are shown to exhibit all types of the studied activities. Acute blood loss reduces the scavenger function of Kupffer cells during the first few hours, especially erythropoietinlike activity. The activities return to normal levels 5 days after blood loss and, after a relatively stable period, they rise again to the end of the recovery period. This is accompanied by an increase in the number of phagocytizing cells and is evidently related to the renewal of their population. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 3, pp. 258–261, March, 1995 Presented by V. P. Kaznacheev, Member of the Russian Academy of Medical Sciences     

Activity of the properdin system in acute blood loss

Summary As shown in experiments on dogs single acute blood loss causes a rapidly appearing and considerable reduction of blood properdin. Gradual normalization of properdin level was observed in 2–5 days after blood loss. With repeated blood loss the tolerance of the properdin system developed quickly, and no properdin level drop was provoked by blood exfusions. It is suggested that the changes of the properdin system activity are one of the factors causing a lower resistance to infection in animals which sustained an acute blood loss.(Presented by Active Member AMN SSSR N. A. Kraevskii) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 54, No. 8, pp. 26–30, August, 1962     

The efficacy of rheopolyglucin-based blood correctors in acute blood loss in rats]

The efficacy of rheopolyglucin and complex blood correctors based on it was demonstrated in experiments on 86 albino male rats. The main renal functions (glomerular filtration and tubular secretion), determined by radionuclide methods, were restored by means of infusion therapy. The effect was produced by the complex action exerted on the main pathogenetic mechanisms of the process. Rheopolyglucin injected into intact rats and rats subjected to blood loss led to a certain increase of the blood histamine level, but did not induce a shock-like reaction. Infusion of an equal volume of isotonic sodium chloride solution was also accompanied with hyperhistaminemia in some of the rats.     

Red blood cell substitutes and artificial blood

Artificial substitutes for specific functional portions of blood are being developed. Perfluorocarbons have received the most publicity in recent years, and one, Fluosol-DA, is undergoing clinical trials in the United States. The perfluorocarbon emulsions physically dissolve oxygen, which distinguishes them from the chemical binding that occurs in hemoglobin. Fluosol-DA has been shown to transport oxygen in amounts that are probably clinically useful if the patient inspires an atmosphere with increased oxygen. A large clinical trial from Japan suggests that Fluosol-DA is safe to transfuse, although recent work suggests that Fluosol-DA may produce significant pulmonary reactions that can be prevented by steroid administration. These reactions are probably caused by complement activation by an emulsifying agent in Fluosol-DA. Recent applications of Fluosol-DA include use in a resuscitative fluid, use in occlusive vascular disease, an special applications, such as treatment of carbon monoxide poisoning, which take advantage of the solubility properties of perfluorocarbons.     

Cardiac damage and protection in acute fatal blood loss

Experiments on dogs and albino non-inbred male rats undergone a 4-5-min clinical death under the conditions of the whole organism and isolated isovolumetric contracting heart revealed phasic systemic hemodynamic and myocardial contractile disorders. The leading pathogenetic factors of postresuscitational cardiac damage are excessive catecholamine stimulation of cardiac beta-adrenoreceptors, impaired energy metabolism, excessive activation of free radical processes, metabolic acidosis, secondary hypoxia, and endogenous toxemia. The heart was found to be at the most damaged within the first hour after resuscitation. The use of antihypoxants, antioxidants, beta-adrenoblockers and Ca-channel blockers were pathogenetically substantiated to diminish postresuscitational cardiac damages.     

Second-generation perfluorocarbon emulsion blood substitutes

A novel series of perfluorocarbon (PFC) emulsions, based on perfluorodecalin (C10F18) and stabilised with up to 2.5% (w/v) of lecithin have been produced for evaluation as injectable, temporary respiratory gas-carrying blood substitutes. Some formulations contained 1.0% (w/v) of perfluorodimorpholinopropane (C11F22N2O2) to retard droplet growth through molecular diffusion (Ostwald Ripening). Other emulsions contained novel, amphiphilic fluorinated surfactants, such as, for example, the monocarbamate, C8F17C2H4NHC(O)(CH2CH2O)2Me (designated compound P6), at 0.1% (w/v) to enhance stability. Emulsions were prepared by homogenisation, were steam sterilisable and were stable for > 300 days (25 degrees C). Injection of rats (7.5 ml kg-1 b.w.) with emulsions produced significant (P < 0.05), transient increases in liver and spleen weights. One emulsion inhibited phorbol 12-myristate 13-acetate (PMA)-stimulated, Luminol-enhanced, chemiluminescence of human polymorphonuclear leucocytes (PMNL) in vitro, suggesting possible applications in ischaemic tissues for suppressing PMNL-mediated inflammation. The P6 fluoro-surfactant inhibited spontaneous platelet aggregation in hirudin-anticoagulated human blood in vitro, suggesting possible applications as an anti-thrombotic agent.