Hemolysis

HEMOLYSIS, HEMATOLYSIS (from Greek haima- blood and lysis- dissolution), a phenomenon in which the stroma of red blood cells, when damaged, releases Hb, which diffuses into the surrounding environment; in this case, the blood or a suspension of red blood cells becomes transparent ('lacquered blood'). H. can be caused by the most diverse causes. When red blood cells are introduced into a medium with lower osmotic pressure than that inside the red blood cells, Hb exits from the red blood cells as a result of damage to the cell membrane, which is stretched by water entering the cell. Hamburger established that H. in such hypotonic solutions of the same molecular concentration of different salts begins at the same degree of hypotonicity, regardless of the type of salt. However, this occurs only with sharp hypotonicity of solutions; in the case where the difference in osmotic pressure between the cell contents and the external solution is so insignificant that H. occurs only after many hours, the rate and intensity of dissolution of red blood cells in iso-osmotic solutions of different salts are not the same (Höber), which characterizes the different influence of ions on H. Although red blood cells of mammals have approximately the same osmotic pressure, they lose Hb differently easily in hypotonic solutions. Red blood cells of horses, for example, have significantly less resistance than human red blood cells, since they begin to release Hb already in a 0.68% solution of sodium chloride, while human red blood cells only in a 0.44% solution. The resistance of red blood cells to various agents is also very different. It is interesting to note that between H. from hypotonicity and H., caused by the action of saponin on red blood cells (see below), there are inverse relationships: the more resistant the red blood cells of a given species are to saponin, the more sensitive they are to hypotonicity, and vice versa. The resistance of different red blood cells of the same blood is also not the same. When distilled water is added to blood, H. occurs first only in the least resistant blood cells and gradually progresses as the blood is diluted, spreading to more resistant red blood cells. Under the influence of certain pathological processes, the resistance of red blood cells can change significantly either in the direction of strengthening or weakening. In addition to physicochemical moments causing H., various chemical effects on red blood cells also cause the release of Hb from them. This occurs in the case where the agent added to the blood dissolves in the stroma of red blood cells and disintegrates its lipoprotein structure. Chemical analysis reveals the following most important components of the stroma (according to Wooldridge and Pascucci):

Nucleoprot

Inorganic lipids (oko-

teid and nucle

loin C, organic lealbumin

substance) (around C,

Cholesterol, lecithin, cerebrin and other lipids are little studied. Hemolysis of lipids can occur as a result of exposure to both the lipid and protein parts of the erythrocyte stroma. Bile acids dissolve red blood cells by dissolving the lecithin of their shells; saponin acts hemolytically due to its strong affinity for cholesterol (Ransom); ether, chloroform and similar narcotics are hemolytic due to their affinity for the lecithin of red blood elements (their effect is detected only in vitro, since practically these substances do not enter the blood in a concentration that could lead to hemolytic phenomena). The hemolysin produced by the tetanus bacillus apparently also destroys the lecithin substance of the erythrocyte stroma. In Pascucci's experiments, artificially prepared lecithin-impregnated membranes, under the action of the mentioned hemolysin, allowed hemoglobin solution to pass through much faster than membranes with cholesterol. According to Bajardi, the action of staphylococcal hemolysin is associated with proteolysis and is based on the breakdown of the proteins of the red blood cell shell. Hemolysins. Hemolysins are products of animal or plant origin, which have the ability to dissolve the erythrocytes of one or many animal species. Ehrlich divides hemolysins into 1) plant hemolysins, 2) bacterial toxins, 3) poisonous secretions of animals (snake venom, scorpion venom, bee venom, etc.) and hemolysins of the sera of higher animals. Of plant hemolysins, saponins, which exhibit hemolytic properties in very small concentrations, are of greatest interest. They act more energetically on erythrocytes washed from serum, since serum neutralizes the action of saponin, due to the presence of cholesterol in it, which forms insoluble compounds with saponin. Due to this property of cholesterol, by adding it to the serum, erythrocytes can be protected from the hemolytic action of saponin. From other plant hemolysins, abrin, crocin, phallin, ricin, robin should be mentioned. Bacterial hemolysins are a secretory product of microbes, separated from bacteria by filtration and belong to the type of exotoxins. Some researchers call them "hemotoxins". They are sensitive to heat and the influence of chemical agents and, when introduced into the animal body, lead to the formation of specific antibodies that neutralize the action of hemolysins. The blood serum of normal animals also has some minor antihemolytic properties, which must be attributed to the cholesterol of the serum (Noguchi). Hemolysins are produced by pathogenic staphylococci, streptococci, the tetanus bacillus, many vibrios, the anthrax microbe, B. subtilis, B. megatherium, B. proteus and others. The mechanism of action of bacterial hemolysins cannot be considered the same: tetanolysin acts on the lecithin part of the erythrocyte shell; staphylococcal hemolysin has its point of application in the proteins of the stroma; regarding the action of products of B. mesentericus, B. prodigiosus, V. Metschnikow, the presence of a lecithin-dissolving enzyme in them is assumed. Heating (at 55-60° for 20-30 minutes) destroys the activity of most bacterial hemolysins, with the exception of a few, more stable ones. It is interesting that the activity of hemolysin can be increased many times (200-250 times) by adding peptone to the filtrate. According to Pribram, this effect occurs due to a change in the distribution of hemolysin between erythrocytes and the environment. Adding peptone reduces the solubility of hemolysin in the surrounding solution and changes the distribution coefficient in favor of the erythrocytes. In vivo, bacterial hemolysins also give a hemolytic effect. With intravenous administration to an animal, hemolysins cause the destruction of erythrocytes, accompanied by hemoglobinuria and the development of anemia. The action of bacterial hemolysins should also manifest itself during the course of infectious diseases caused by microbes producing hemolytic poisons. To detect anemizing action, high concentrations of hemolysins are not necessary. When injecting 2 cubic cm of staphylococcal hemolysin (two drops of which can cause hemolysis of 5 cubic cm of a 5% suspension of erythrocytes) into a rabbit weighing 1 kg, anemia develops after 5-6 days, explained by the fact that although such an amount of hemolysin cannot cause complete hemolysis of any noticeable amount of erythrocytes, the hemolysin, distributed evenly over a large number of erythrocytes, without dissolving them, damages them so much that they undergo phagocytosis and destruction in the reticuloendothelial apparatus. The possibility of such anemizing hemolytic influences from the intestinal microflora is not excluded. Hemolysins of animal origin can also in some cases show an anemizing influence from the intestine. This should include the hemolytic poisons of worms, especially Bothriocephalus, the presence of which in the intestine, as is known, is associated with pernicious anemia by some researchers (Tallquist, Faust). The venom of insects (bees, spiders, scorpions) and snakes also contains hemolytic substances. In the venom of the cobra, there is a hemolysin that dissolves erythrocytes only in the presence of serum. The activating effect of the latter on the venom depends on the presence of lecithin in it (Kyes, Noguchi), which plays the role of a complement (see below). It should be noted that the toxicity of snakes is not limited to the secretion of their venom glands; their blood, when administered parenterally to other animals, shows a high degree of toxic action. The toxicity of heterologous sera, although to a much lesser extent, is also characteristic of mammals, and this effect is observed when administered not only into the bloodstream, but also subcutaneously and intraperitoneally (Uhlenhuth). Uhlenhuth and Pfeiffer associate the toxic action of sera with their hemolytic properties. Indeed, only a few sera do not have these properties, at least with respect to human erythrocytes (namely - horse, donkey, goat and sheep sera). Most sera, however, are hemolytic to one degree or another for erythrocytes of a foreign species. Hemolysins of foreign sera (normal, non-immunized animals) are called "normal hemolysins". However, the phenomena of hemolysis by no means exhaust the toxic action of a foreign serum, resp. blood. It is necessary to take into account the formation of enzyme-like substances during blood clotting, the action of fibrin ferment, and the change in the colloids of the body in connection with the introduction of foreign colloidal substances (for more details - see Serum sickness). In a number of sera of various mammalian species, the most toxic are cat and bull sera; pig, ram, horse sera are significantly less toxic (Weiss). They are lethal to rabbits with intravenous administration per kg: Blood serum Eel.............. 0.02-0.05 cubic cm Cat............. 8.0

» Human............10.0-27.0 » » Sheep .............12.0-20.0 » » Horse.............44.0-50.0 » » When animals are immunized with erythrocytes of another species, the serum acquires marked hemolytic properties in relation to the erythrocytes used for immunization, due to the formation of specific hemolysins, or immunohemolysins (Wog-det). For example, when sheep erythrocytes are introduced parenterally into a rabbit, hemolysins are obtained that dissolve the red blood corpuscles of sheep, but not of other animals. When the hemolytic serum is heated for half an hour at 55° or when it is stored, its lytic properties disappear, the serum becomes inactive; but it is reactivated when serum from a normal animal is added, which itself does not possess hemolytic properties. From this it follows that hemolysins consist of 2 elements: one that is easily destroyed, in particular by the action of temperature (thermolabile), and another that is more stable (thermostable). The latter substance, present in immune serum (and in small quantities in some normal sera—"normal hemolysins"), was called the "sensitizer" (Bordet), the "fixer" (Metchnikoff), or the "amboceptor" (Ehrlich). The distribution of these substances in normal and immune sera is as follows: Serum Amboceptor + + Complement Immune fresh...... » heated ...... Normal fresh..... + + The thermolabile substance, found in both fresh immune serum and normal serum, is called "alexin" (Buchner), "cytase" (Metchnikoff), or "complement" (Ehrlich). For the blood serum of the immunized animal to acquire hemolytic properties, a minimal dose of foreign erythrocytes is sufficient (1.0-1.5 mg of a 5% suspension of erythrocytes in physiol. solution). Precise research shows that the action of immunohemolysins, like other immune bodies, is not strictly specific. Serum obtained from immunization with human erythrocytes also acts on monkey erythrocytes; serum against chicken erythrocytes also dissolves the red blood corpuscles of pigeons. These so-called "group hemolysins" usually act on the group antigen to a lesser degree than on the one used for immunization. In some cases, the antigen for hemolysins may not be erythrocytes but organs, and the antigen is heterogeneous in relation to the hemolysins formed ("heterogeneous hemolysins"). When a rabbit is immunized with organs of a guinea pig, hemolysins appear that dissolve the erythrocytes of sheep blood (Forssman, Krichevsky and others). Besides the guinea pig, the organs and some other animals (horse, donkey, dog, cat) contain an antigen that, when used for immunization, produces hemolysins for sheep erythrocytes. These "guinea pig type" animals are contrasted with the "rabbit type," which includes rabbit, human, rat, ox, pig, and which does not possess this heterogeneous antigen. The Forssman antigen is present only in organs, while it is absent in erythrocytes. The explanation for these phenomena must be sought in the fact that in the tissues of different animal species there are proteins containing identical complex radicals that have the same antigenic properties. The relationship between the antigen (erythrocytes), amboceptor, and complement is illustrated by the following experiment. After one hour of contact between complement (fresh serum) and erythrocytes, the latter are separated by centrifugation and amboceptor (immune serum, heated ¹/₂ hour at 55°) is added to them—hemolysis does not occur. If, on the contrary, amboceptor is first added to the erythrocytes, and then, after centrifugation, it is replaced with complement—hemolysis will occur. Thus, complement cannot act directly on erythrocytes; it causes hemolysis only through the amboceptor that fixes to the erythrocytes. According to Ehrlich, the amboceptor, which belongs to the third-order receptors, has two hapten groups: one for binding with the antigen, the other with complement (which is why it is also called the intermediate body). Complement also has two groups, one of which (hapten) it connects with the amboceptor, and the other (zymogen) produces the lytic effect. Despite the extensive literature devoted to the question of hemolysins, neither the amboceptor nor the complement has received any sufficient chemical characterization. Amboceptors apparently should be classified as protein substances—pseudoglobulins; complement, according to the research of most authors, is a substance close to lipoids and is probably a protein-lipoid compound (Landsteiner). The role of colloids and lipoids in the phenomena of H. is sufficiently demonstrated in the experiments of Landsteiner, who managed to establish that H. in the mixture: silicic acid+lecithin—proceeds completely analogously to the system: amboceptor + complement. According to Liebermann (Liebermann), oleic acid by itself is almost non-hemolytic, protein-soap solutions also do not cause hemolysis, but when they are combined together, a sharp hemolysis of erythrocytes occurs due to the liberation of soaps that have the ability to dissolve red blood corpuscles. The mixture of oleic acid and protein-soap compounds behaves analogously to hemolysins—it is inactivated at 55° and can be reactivated by adding a small amount of protein-soap compound. At present, the adsorption theory of the action of hemolysins, first put forward by Bordet, is acquiring ever greater importance. According to this theory, the sensitizer (amboceptor) is considered as a mordant, thanks to which the erythrocyte is prepared for the H.-causing action of alexin (complement).—According to the research of Rohner, the phenomena of H. in quantitative determination follow the laws of the so-called adsorption isotherm. According to the view of some authors (Barykin, Zilber), in the phenomena of H., not special substances—amboceptor and complement—react, but the differences in the functions of immune and normal sera, connected with a certain state of their colloids, are manifested. (For the formation of immunohemolysins—see Immunity.) e. tatarshinov. Hemolysis In vivo. * Under normal conditions in the animal organism, constant * Whereas biological chemistry uses the term "hemolysis" to imply the exit of Hb from the vessel, pathology and clinic use this term to denote the entire process of destruction of erythrocytes in the organism. In this latter sense, the word "hemolysis" will be used in this section. the formation and destruction of erythrocytes occurs; this process can be called blood exchange. According to older data, each human erythrocyte lives about 30 days (Quincke, Eppinger), in dogs 20-30 days, according to more recent data—considerably longer: in humans 100-150, in dogs about 80 days (McMaster and Ellmann, Lichtenstein and Terven, Adler and Bressel). Under normal conditions, those erythrocytes are destroyed that, having lived their term, have matured for destruction, i.e., have changed physico-chemically to a corresponding degree and in a corresponding ratio. In which organs, in which tissues, and in what manner does this normal H. occur? In higher mammals, H. apparently occurs in the reticular and endothelial cells of the spleen, liver, bone marrow, and lymph glands (ret.-end. system). But among these organs, the spleen occupies a special place in relation to H., because on the basis of a series of data it must be assumed that it has the function of accelerating those physico-chemical changes in erythrocytes that lead to their destruction. These data are as follows: 1) decreased osmotic resistance of erythrocytes in the blood of the spleen and splenic vein compared with arterial blood and blood of veins of other areas (Bolt and Heeres, Orahowats, Dreisbach and others); 2) increased osmotic resistance of erythrocytes after splenectomy (Eppinger, Austin and Krumbhaar, Istomanova, Miasnikov and Svyatskaya and others); 3) decreased excretion of bilirubin (a product of the transformation of Hb of destroyed erythrocytes by the liver) after splenectomy (Banti, Pugliese, Pchelina, Sagia and Hizai); 4) weaker action of some hemolytic poisons, e.g., toluylenediamine, after splenectomy (Banti, Eppinger, Miasnikov, Istomanova and Svyatskaya) and 5) the generally recognized favorable results of splenectomy in hemolyic jaundice. The decrease in osmotic resistance of erythrocytes with their age (Brinckmann, Snapper, Aschner, Simmel, Istomanova and Miasnikov and others) and the most pronounced decrease in osmotic resistance of erythrocytes in the familial form of hemolytic jaundice, i.e., in that very disease in which the most marked intensification of H. is observed, and not due to the increased hemolytic ability of the spleen in this disease, but due to a congenital anomaly of erythrocytes—these two facts undoubtedly give the right to consider that the decrease in osmotic resistance of erythrocytes is one of the manifestations of those physico-chemical changes that occur in erythrocytes when they mature for natural death by H. On the basis of all these data, it must be recognized that erythrocytes in the spleen are subjected to an influence, thanks to which their maturation for H. is accelerated ("Andauung" of Eppinger).

This function of the spleen is compatible with its reservoir function (Barcroft) without danger of harm to the composition of the blood, since the indicated changes occur in the erythrocytes as soon as they enter the spleen, but with further residence in it they no longer progress (Orahowats, Wicklein). What are the changes that erythrocytes undergo in the spleen? According to the works of Snapper and Brinkman, the osmotic resistance of erythrocytes depends on the ratio of cholesterol and phosphatides (lecithin) on their surface or in their shell, with the former increasing and the latter decreasing the osmotic resistance of erythrocytes. With the change in the ratio of these substances on the surface of erythrocytes, other changes in the physicochemical properties of mature erythrocytes prone to hemolysis may also be associated, for example, an increased tendency to adhesion (see below). Whether the spleen can regulate H. by changing this function, i.e., strengthen or weaken it, this question has not yet been resolved. Erythrocytes, undergoing certain physicochemical changes in the spleen, are partly phagocytosed here, in the spleen, by reticuloendothelial cells. Here, those erythrocytes are probably phagocytosed which enter the spleen at such an age that the indicated effect of the spleen is sufficient for them to be phagocytosed. Phagocytosis of erythrocytes prepared by the spleen continues in the Kupffer cells of the liver, where erythrocytes from the spleen enter first. The direction of blood flow from the spleen to the liver creates the impression of cooperation between these organs in regard to H. Matured for destruction but not captured by phagocytes of the spleen and liver, red blood cells enter the general circulation and, among other places, into the vessels of the bone marrow and lymph., resp. hemolymphatic glands. The reticuloendothelial cells of these organs undoubtedly also phagocytose erythrocytes and thus also play a role as organs of H. Why are only those erythrocytes that are mature for H. subjected to phagocytosis, or more precisely, by what method do reticuloendothelial cells capture exactly these, the oldest erythrocytes, and not others? Obviously, this is due to the same physicochemical changes that are characteristic of erythrocytes mature for H., perhaps due to an increased tendency to adhesion or sticking. The slowed blood flow in all those organs where H. occurs (sinuses of the spleen and similar formations of the bone marrow, liver capillaries) should promote the adhesion of these erythrocytes to the so-called 'shore' cells (Uferzellen), i.e., to endothelial and reticular cells. The erythrophagocytic function of these cells can vary quantitatively within wide limits, depending on the need in the sense of the presence in the blood of red blood cells subject to destruction. Whereas previously among the mentioned organs the liver and spleen were given main importance as organs of H., at present it is believed that the bone marrow also takes a large part in H. (Mann and Magath, Askanazy, Peabody and Braun, Doan). That phagocytosis of whole erythrocytes by reticuloendothelial system cells is the only way under normal conditions for the destruction of erythrocytes in the body is not recognized by all. Rous, Robertson, Doan, and Sabin assert that the normal and main way of destruction of erythrocytes is fragmentation occurring in the blood itself, i.e., the breakdown of red blood cells into small pieces (fragments) by pinching off small particles. The slowed process of fragmentation manifests as poikilocytosis, fragments of erythrocytes are the so-called schistocytes, described by Ehrlich. The fragments are phagocytosed by the same cells that, according to the prevailing theory, phagocytose whole erythrocytes, i.e., by cells of the reticuloendothelial system. The method of destruction of erythrocytes by fragmentation cannot yet be considered proven. Finally, Fahraeus describes spherical, colorless, and transparent formations in fresh blood preparations as a constant morphological element of normal blood. He considers these formations to be the stroma of erythrocytes and assumes that they indicate a constantly occurring normal method of destruction of erythrocytes in the blood. Against this assumption speaks the fact that normally Hb is determined only in negligible traces. Fahraeus believes that Hb is very quickly captured by reticuloendothelial cells. Be that as it may, the further stages of hemolysis obviously occur in the cells of the reticuloendothelial system. What products are obtained in this process and what is their further fate? The fate of the components of the stroma, in particular its lipoids, is completely unknown to us. Hb breaks down into the iron-containing pigment-hematine and the protein substance-globin. The further fate of the latter is also unknown to us. Hematine is split into a pigment particle and some iron compounds-apparently unstable protein or lipoid compounds of colloidal iron, resp. iron oxide, called hemosiderin, as their presence is determined by microscopic reactions for iron. These iron compounds accumulate in reticuloendothelial cells in general and in the liver and spleen in particular (hemosiderosis, see Hemosiderin) and there are apparently processed as needed into other compounds, in which form iron is transferred to the erythroblastic tissue (under normal conditions-to the bone marrow) and utilized there in the production of new Hb. To what extent the spleen has a special role in the accumulation of iron and in general in the regulation of its exchange (Asher) is still controversial. The pigment particle of hematine is converted into bilirubin. The question of the place of this conversion is currently resolved in the sense that bilirubin is formed in the cells of the reticuloendothelial system in the spleen, liver, and bone marrow, possibly also in lymph., resp. hemolymphatic glands (Aschoff, Mann-Magath). The question of whether the larger part of bilirubin is formed in the liver or in the bone marrow is not yet resolved (Rosenthal, Mann-Magath). Since bilirubin is formed in the cells of the reticuloendothelial system and iron is deposited there as a result of Hb breakdown, it is most probable that the breakdown of phagocytosed erythrocytes into globin and hematine, as well as the detachment of Fe from the pigment particle and its conversion into bilirubin, occur in the cells of the reticuloendothelial system of the liver, spleen, and bone marrow. From the cells of the reticuloendothelial system of the bone marrow and spleen, bilirubin enters the blood of the general circulation or the portal system and is excreted by the liver into the bile. Bilirubin produced by Kupffer cells is also excreted by liver cells into the bile, but it is unclear how it is transferred to them-through the lymph, blood, or by means of special processes of Kupffer cells extended to the surface of liver cells (Roessle, Rosenthal and Holzer). The influence of various physiological factors on H. has been little studied; there are indications that meat food enhances H. (Morawitz and Kuehl, Adler and Sachs). Physical work also has an enhancing effect on H., if it is preceded by a long period of rest, but prolonged physical work causes hyperplasia of the bone marrow and enhanced erythropoiesis, which with excess compensates for the increased H. By what method H. is regulated in the body is also unknown. The composition of the blood undoubtedly has an influence on it in the sense that anemia causes a reflex decrease in H. (Belonogova), and polycythemia - its intensification (Krumbhaar and Chanutin). With pathological intensification of hemolysis, an increase in the amount of bilirubin in the bile (pleiochromia) and a corresponding increase in urobilinogen in the feces is observed first; urobilin in the urine increases only with very intense intensification of H., and then mainly with a violation of the corresponding function of the liver; then, as H. intensifies, hyperbilirubinemia and jaundice appear when the liver is no longer able to excrete the bilirubin produced in excessive quantities. Hyperbilirubinemia as a result of intensified H. usually differs in that bilirubin in the serum gives the so-called indirect Hymans van den Bergh reaction, whereas jaundice due to intensified H. is not accompanied by skin itching, and the amount of cholesterol in the serum and bile acids in the urine is not increased (see Hemolytic jaundice). With intensified H. under the influence of specific hemolysins and many hemolytic poisons, hemolysis occurs in the blood itself, as evidenced by the observed hemoglobinemia. If hemoglobinemia due to such pathological H. is not particularly strong, it is not accompanied by hemoglobinuria (see), since Hb is quickly absorbed from the blood by the cells of the reticuloendothelial system. Only with significant hemoglobinemia does hemoglobininuria occur, as is the case with paroxysmal hemoglobinuria. With intensified H., simultaneously with Hb, hematine and other products of Hb transformation sometimes appear in the plasma.

The histological manifestation of increased hemolysis is considered hemosiderosis, although there is no constant relationship between them; on the other hand, the accumulation of iron in the corresponding organs (mainly in the liver and spleen) may depend on other causes, as is the case, for example, in hemochromatosis (see). Patho-anatomically, increased hemolysis manifests as hyperemia and enlargement of the spleen, and to some extent the liver, hyperplasia of reticulo-endothelial cells in these same organs with increased erythrophagocytosis in them, as well as in the bone marrow (Askanazy, Peabody and Braun, Doan). In severe hemolysis, which sometimes develops in acute septic cases, its morphological manifestation may be the imbibition of blood pigment into the intima of vessels and endocardium, which occurs very rapidly after death. Among diseases, markedly increased hemolysis is characteristic of hemolytic jaundice (see) and to a lesser degree of pernicious anemia (so-called cryptogenic and diphyllobothriasis). As already mentioned, the increased hemolysis in hemolytic jaundice is a consequence of a congenital anomaly of erythrocytes. According to the latest data (Morawitz and Belonogova), in pernicious anemia, the increase in hemolysis is also a secondary phenomenon, also caused by the pathological structure of erythrocytes as a result of primarily altered erythropoiesis. Among infectious diseases, malaria and sprue proceed with a pronounced increase in hemolysis, and the anemia accompanying it resembles pernicious anemia. Among professional poisonings, saturnism is apparently accompanied by increased hemolysis (Berezin, Fisher and Nikulina) (see Hemolytic poisons). Among substances used for therapeutic purposes, salvarsan causes a marked increase in hemolysis (Belonogova, Kasatkin); arsenic possesses this property to a much lesser degree. Iron, on the contrary, apparently somewhat lowers hemolysis (Belonogova). Finally, hemolysis is often observed in certain septic infections, especially in so-called 'bilious' ones (for example, relapsing fever, lobar pneumonia). In the experiment, the most accurate picture of hemolysis is obtained by determining the amount of bilirubin in the bile excreted through a fistula of the common bile duct (McMaster); but with prolonged loss of all bile in dogs, anemia develops, which in turn can affect hemolysis (McMaster, Seyderhelm). In clinical practice, an increase in hemolysis is often judged by increased bilirubinemia and urobilinuria, but both of these methods are incorrect, since hyperbilirubinemia and urobilinuria are determined to a greater extent than by hemolysis by the state of the corresponding liver function. The nature of the reaction of Hijsmans van den Berg does not determine the pathogenesis of hyperbilirubinemia with any precision. Eppinger's proposal to determine hemolysis in humans by the amount of bilirubin in duodenal contents is impractical due to the inconsistency of bile content in it and the inconsistency of its composition in terms of the participation of concentrated 'gall bladder bile' and non-concentrated 'liver bile'. More accurate data are obtained when determining hemolysis by the amount of urobilinogen in the feces, but this method is by no means flawless, since not all Hb or, more precisely, not the entire mass of the pigment particle of destroyed erythrocytes appears in the feces. Part of it, perhaps, is used before being converted to bilirubin for the construction of new Hb. Then a significant part (up to 2/3) of urobilinogen (into which all bilirubin is converted in the intestine) is absorbed from the intestine and with the portal blood enters the liver. The further fate of this part of urobilinogen is unclear; a significant part, apparently, is converted back by the liver into bilirubin and is again excreted in the bile; another part passes through the liver into the general circulation and is partly excreted by the kidneys, and partly, perhaps, is used for the construction of new Hb. In addition, it is possible that part of the urobilinogen is destroyed either in the intestine or in the liver. Therefore, the direct calculation of the number of erythrocytes subjected to hemolysis per day or their duration of life by the amount of urobilinogen in the feces is completely inaccurate. With constipation, the amount of urobilinogen excreted with the feces decreases, with diarrhea it increases. If there is significant urobilinuria (due to liver insufficiency), it is necessary to determine the sum of urobilinogen in the feces and urine to determine the degree of hemolysis. Due to significant fluctuations in the amount of urobilinogen in the feces, it is necessary for a correct assessment of hemolysis to always take the average daily amount of urobilinogen from determinations over at least 4-5 days. The most suitable method for quantitative determination of urobilinogen in urine and feces is the Terven method. Usually, hemolysis is judged by the average daily amount of urobilinogen in the feces and urine; in normal conditions it ranges from 50 to 193 mg, the average daily amount corresponds to approximately 120 mg. It is more correct to determine hemolysis by the amount of urobilinogen excreted per day per 100 g of Hb. With such a calculation, the average normal number is 30 mg. In hemolytic jaundice, the daily amount of urobilinogen reaches 1,500 mg, in pernicious anemia - 500 mg, in secondary anemias it decreases to 25 mg.

g. Lang.