Prospective Assessment of Hepcidin in Relation to Delayed or Immediate Graft Function in Patients Undergoing Kidney Transplantation

BACKGROUND

Hepcidin is a peptide hormone that regulates iron homeostasis. Hepcidin may represent an early, predictive biomarker of acute kidney injury, another model of ischemia-reperfusion injury. Urinary hepcidin-25 has been shown to be elevated in patients who do not develop acute kidney injury. Creatinine is an unreliable indicator during acute changes in kidney; therefore, the aim of the study was to assess whether hepcidin could predict renal outcome in 31 consecutive patients undergoing kidney allograft transplantation. Serum hepcidin was evaluated before and after 1, 3, 6, and 10 days after kidney transplantation, using commercially available kits. Serum creatinine was assessed at the same time.

METHODS

We found a significant decrease in serum hepcidin, as early as after 1 day after kidney transplantation. Before transplantation, serum hepcidin was related to creatinine. In patients with delayed graft function, there was no decrease in serum hepcidin.

RESULTS

Our findings may have important implications for the clinical treatment of patients undergoing kidney transplantation. The "window of opportunity" is narrow in delayed graft function to distinguish between acute rejection and calcineurin inhibitors nephrotoxicity, and time is limited to introduce proper treatment after initiating insult.

CONCLUSIONS

Hepcidin must be investigated as a potential early marker for delayed graft function, especially in the upcoming setting of early dialysis treatment or anti-rejection therapy and might contribute to early patient risk stratification.

Diet and the content of selenium and lead in patients with abdominal aortic aneurysm

BACKGROUND

To evaluate the content of selenium (Se) and lead (Pb) and the influence of dietary habits and smoking in patients with abdominal aortic aneurysm (AAA).

PATIENTS AND METHODS

Forty-nine patients with AAA prior to surgical procedures aged 42 - 81 years and a control group of 22 healthy volunteers aged 31 - 72 years and 17 aortic wall samples from deceased were included in the study. Food-frequency questionnaires were implemented in AAA patients to collect the dietary data. Se and Pb concentrations in the serum and blood, respectively, and in arterial wall and parietal thrombus samples were determined by the atomic absorption spectrometry method.

RESULTS

The mean Se level in serum of patients with AAA (60.37 ± 21.2 cm/L) was significantly (p < 0.008) lower than in healthy volunteers (75.87 ± 22.4 cm/L). We observed a significant correlation (r = 0.69, p < 0.0001) between the content of Se in serum and the parietal thrombus of examined patients. Se concentration in aortic wall was inversely correlated to the concentration of Pb (r = - 0.38, p < 0.02). We observed significantly lower (p < 0.05) concentrations of Se (39.14 ± 37.1 cm/g) and significantly higher (p < 0.05) concentrations of Pb (202.69 ± 180.6 cm/g) in aortic wall samples of smoking patients than in non-smoking patients (77.56 ± 70.0 cm/g, 73.09 ± 49.8 cm/g; respectively).

CONCLUSIONS

Se serum level is lower in patients with AAA than in healthy volunteers. In aortic wall, Se concentration is inversely correlated with Pb concentration. Dietary habits and smoking have an influence on the Se and Pb status in patients with AAA.

Glycosaminoglycan-degrading enzymes in the varicose vein wall

AIM

Mechanical properties of the vein wall are determined by extracellular matrix components, including glycosaminoglycans (GAGs). The aim of the study was to evaluate the activity of enzymes involved in GAGs degradation pathway in the wall of varicose veins and varicose veins complicated by thrombophlebitis, when compared to the wall of normal ones.

METHODS

Normal, varicose veins and varicose veins complicated by thrombophlebitis were collected during surgical treatment of 10 patients. Activities of endoglycosidases, sulphatases and exoglycosidases were assessed according to colorimetric methods.

RESULTS

Activities of neutral endoglycosidases degrading chondroitin-4-sulphate (C4S) and heparan sulphate (HS) were decreased, whereas activities of neutral endoglycosidases degrading dermatan sulphate and hyaluronic acid were increased in varicose veins and varicose veins complicated by thrombophlebitis. Activities of acidic endoglycosidases degrading C4S and HS were decreased in varicose veins and varicose veins complicated by thrombophlebitis, whereas activity of acidic endoglycosidases degrading chondroitin-6-sulphate was decreased only in varicose veins complicated by thrombophlebitis. Furthermore increased activities of arylosulphatase B, beta-N-acetylhexosaminidase and alpha-L-iduronidase were demonstrated in varicose veins, as well as in varicose veins complicated by thrombophlebitis.

CONCLUSIONS

Changed activities of GAGs-degrading enzymes may contribute to previously reported changes in the content and molecular differentiation of GAGs in the wall of varicose veins that may play a role in the disease pathogenesis.

Activity of coagulation and fibrinolytic system components in the vein thrombus

PURPOSE

Behaviour of the vein thrombus is determined by the activity ratio of coagulation factors to factors of fibrinolytic system. The aim of the study is to evaluate activity of some coagulation and fibrinolytic factors in the vein thrombus.

MATERIAL AND METHODS

The activity of platelets aggregating factors, tissue factor, thrombin, antithrombins, antiheparin factors, plasminogen activators, plasmin (plasminogen) and antiplasmins of the vein thrombus homogenate was determined using coagulative, fibrinolytic and caseinolytic tests. Retracted blood clot was a compared material.

RESULTS

Tissue factor activity in the vein thrombus was above twofold higher and antiheparin activity was nearly twice higher in comparison to the blood clot. The vein thrombus contains also active thrombin. Plasminogen activators activity in the vein thrombus was twofold higher and activity of plasmin (plasminogen) was threefold higher than in the blood clot. High activity of the tissue factor, substances neutralizing heparin and presence of thrombin intensify the thrombus enlargement. However, the thrombotic tendency may be balanced by a high activity of plasminogen activators and high activity of plasmin (plasminogen).

CONCLUSIONS

1) Vein thrombus is characterized by high activity of tissue factor, presence of active thrombin and high antiheparin activity. 2) High coagulative potential of vein thrombus is balanced to a certain grade by high fibrinolytic potential: high activity of plasminogen activators and high activity of plasmin (plasminogen), as well as absence of antiplasmins activity.

Renal Artery Resistance Index, Thyroid Hormones, and Thyroid Volume in the Early Kidney Transplants Recipients

BACKGROUND

Thyroid hormones could affect renal function, and, on the other hand, renal dysfunction may affect thyroid function. Disturbances of concentrations of thyroid hormones are often associated with thyroid gland enlargement. The aim of the study was to assess the function and morphology of the thyroid (volume and hormones concentration) and kidney function after transplantation (creatinine concentration and resistance index [RI] of transplant artery).

MATERIAL AND METHODS

The group included 13 females, 19 males; aged 19-69 years, mean 44.75 +/- 14.8 years after transplantation with stable graft function. Thyroid volume, renal artery RI, creatinine concentration, and concentrations of T3, rT3, FT3, FT4, and TSH were estimated the day before surgery, and at 1, 3, 6, and 10 days after transplantation.

RESULTS

The statistical analysis revealed a negative correlation between delta RI (difference between RI at 3 and 6 days after transplantation) and serum creatinine concentration, 10 days after transplantation (r = -0.63; P < 0.01). We also observed a negative correlation between creatinine serum concentration at 10 days after transplantation and delta thyroid volume (Delta Vol; r = - 0.48; p < .05), a positive correlation between delta FT4 (Delta FT4) serum concentration, and delta creatinine (Delta Crea; r = 0.73; P < .001).

CONCLUSIONS

The dynamics of RI changes in the transplant kidney artery between 3 and 6 days after transplantation may predict graft function. Together with improved kidney function at 10 days after transplantation, we observed a regression of goiter.

The effect of temperature, acidification, and alkalization changes as well as ethanol on salivary cathepsin D activity

The activity of salivary cathepsin D undergoes inactivation at the temperature of 50-60 degrees C and at pH of 2.0 and pH of 8.0-10.0. The enzyme activity is also decreased by high concentrations of ethanol and high-proof alcoholic beverages. The factors should be taken into consideration in the evaluation of salivary cathepsin D activity.

The choice of conditions for cathepsin D activity determination in human saliva

The aim of the study was the demonstration and choice of conditions for the determination of cathepsin D activity in human mixed saliva. The 6% solution of hemoglobin, denatured with hydrochloric acid, was used as the substrate. The ratio of saliva volume to hemoglobin was 4:1 w/v. The reaction was interrupted by adding 10% trichloroacetic acid, after 6 hours of incubation at 37 degrees C. The increase in degradation products was determined with the use of Folina and Ciocalteau method with copper modification.

Matrix metalloproteinases in the vein wall

AIM

Matrix metalloproteinases contribute to extracellular matrix remodelling that can influence mechanical properties of the vein wall and predispose to varicose veins development. The aim of the study was to assess the following matrix metalloproteinases in the wall of varicose veins: tissue collagenase I (MMP-1), gelatinase A (MMP-2), gelatinase B (MMP-9) and stromelysin 1 (MMP-3).

METHODS

Normal, varicose and varicose veins complicated by thrombophlebitis were collected during the surgical treatment of 26 patients. In harvested tissues the presence of gelatinases was detected with zymography, contents of MMP-1, MMP-2, MMP-3 and MMP-9 were evaluated with ELISA, activity of MMP-1 was assessed with HPLC and activity of MMP-2 with ELISA.

RESULTS

Zymography demonstrated particularly high contents of both gelatinases in the wall of varicose veins complicated by thrombophlebitis. The contents of MMP-1, MMP-2 and MMP-9 were significantly increased only in the wall of varicose veins complicated by thrombophlebitis, whereas the increased content of MMP-3 was also found in the wall of varicose veins. A significantly higher activity of MMP-1 was shown only in the wall of varicose veins complicated by thrombophlebitis, whereas an active form of MMP-2 was increased in the wall of varicose, as well as varicose veins complicated by thrombophlebitis, when compared with normal ones.

CONCLUSION

The wall of varicose veins, particularly those complicated by thrombophlebitis shows extensive alterations in the content and activity of matrix metalloproteinases, that may result in extracellular matrix remodelling, influence mechanical properties of the vein wall and predispose to further progression of the disease.

Assessment of connective tissue fibres in walls of allogenic arterial grafts preserved by the method of cold ischemia--a preliminary report

The aim of the study was to evaluate microscopic changes in the wall structures of allogenic arterial grafts, preserved by the method of cold ischemia in relation to the storage period and to test the possibility of the storage period prolongation by allograft freezing at -70 degrees C. The middle layer ultrastructure is well preserved till 30 days from allograft harvesting, however, allograft freezing results in total destruction of elastic and collagen fibres in the arterial wall. An application of allogenic arterial grafts, preserved by the method of cold ischemia till 30 days from their harvesting, seems an efficient therapeutic method in the treatment of patients with synthetic vascular graft infection. Further prolongation of the storage period at -70 degrees C made the allograft useless for implantation.

Haemoglobin of varicose vein, varicose vein with thrombophlebitis and in parietal thrombus of varicose vein

Saphenous veins were taken for examination: unchanged, varicose with thrombophlebitis and varicose thrombus. The contents of haemoglobin and protein were determined in the homogenate of that material. Only small quantities of haemoglobin were found in walls of unchanged veins. Greater amounts of haemoglobin were observed in walls of varicose veins, especially in walls of varicose veins with thrombophlebitis. The varicose vein thrombus also contained marked quantities of haemoglobin.

Amidolytic activity of plasma euglobulins

Amidolytic activity of plasmin, produced in euglobulin fraction, does not correlate with the time of euglobulin fibrinolysis. It does not depend on fibrinogen concentration.

Chemical compound content and enzyme activity in supernatant and sediment of liver homogenate

Evaluation was performed of chemical compound contents and enzyme activities in the whole homogenate, its supernatant and sediment. Six rabbit livers were pulverized in liquid nitrogen and homogenized. After centrifugation, the contents of protein, haemoglobin, vitamin A, vitamin E, vitamin C, as well as the activities of cathepsin B, cathepsin D, superoxide dismutase, catalase, glutathione peroxidase and reductase were assessed in the whole homogenate, its supernatant and sediment. Protein, vitamin A, superoxide dismutase, catalase, cathepsin D, glutathione peroxidase and reductase reveal uniform localisation. Vitamin C and cathepsin B are localized in supernatant, whereas haemoglobin is localized mainly in sediment. Evaluation of chemical compounds and enzyme activities should be performed in the whole homogenate, supernatant and sediment to obtain a real interpretation of biochemical disturbances in the investigated material.

Some components of oxidative-antioxidative system in human blood plasma and serum

Comparison of the concentrations and activities of components in the oxidative-antioxidative system between blood plasma and serum. Blood plasma and serum samples were obtained from 38 healthy adults to evaluate malondialdehyde concentration, the total antioxidative capacity, superoxide dismutase activity, protein and non-protein sulphydryl groups, ascorbate, haemoglobin, methaemoglobin and protein. Blood plasma shows higher activity of superoxide dismutase, as well as higher concentrations of low-molecular sulphydryl groups and ascorbate, when compared to those in blood serum. The total plasma antioxidative capacity is also higher than that assessed in blood serum. Processes of blood coagulation and blood clot retraction lead to antioxidant consumption. The evaluation of oxidative-antioxidative system for diagnostic purposes should be performed in blood plasma.

[Activation mechanisms, biological role and inhibitors of metalloproteases in the extracellular matrix]

Prometalloproteinases are activated by serine proteases, MMP-3, leucocytic elastase, furin, furin-like proteases and by membrane-type metalloproteinases as well. They form complexes with some proMMPs and thus they modify their activation.

[Proteolytic activity of placenta with EPH-gestosis determined by casein and azocasein]

Total proteolytic activity, activity of cathepsin B, activity of cysteine cathepsins and contents of protein degradation products were determined in placentas of pregnancies complicated with mild, moderate and severe EPH-gestosis and in placentas from normal pregnancies. The highest activity of all the determined proteases was observed in placentas of pregnancies complicated with severe EPH-gestosis. The placentas of pregnancies complicated with severe EPH-gestosis also include the highest amounts of aminoacids and low-molecular peptides.

[Experimental aortic aneurysm]

Experimental aortic aneurysm may be evoked in animals by application of chemical compounds disturbing biosynthesis, posttranslating modifications and degradation of elastin and collagen, local damage of the aortic wall by chemical, thermal and mechanical factors and by increased blood pressure. Administration of protease inhibitors, anti-inflammatory drugs, agents enhancing synthesis and formation of elastic and collagen fibers and hypotensive drugs prevent formation enlargement and rupture of aneurysm.

[Activity of cathepsin B and cystatins in the placenta during EPH-gestosis]

Activity of cathepsin B using Bz-DL-Arg-pNA contents of SH-group by means of Ellman method, activity of cystatins against papain using casein as a substrate and contents of deoxyribonuclein acids by Burton method were determined in 64 placentas of pregnancies with EPH-gestosis and in 36 placentas of physiological pregnancies. The placentas from pregnancies with EPH-gestosis showed markedly higher activity of cathepsin B, no difference in the contents of SH-group, slightly higher activity of cystatins and they contain less deoxyribonucleic acids than the placentas from physiological pregnancies. The obtained results show that proteolytic--anti-proteolytic balance in placentas from pregnacies with EPH-gestosis is changed to the advantage of cathepsin B. This protease may in formation of structural and functional changes observed in placentas during EPH-gestosis.

Anticoagulative effect of pepsin

Anticoagulative effect of pepsin is observed in vitro when its concentration is 36 microM and higher. This effect is due to inhibition of fibrin monomer polymerization. Protamine abolishes anticoagulative effect of pepsin. Pepsin does not influence platelet aggregation induced by ADP and collagen.

Coagulative and fibrinolytic activity in parietal thrombus of aortic aneurysm

Lumen of aortic aneurysm is usually filled with parietal thrombus. Behaviour of the parietal thrombus is determined by the ratio of coagulation factors to factors of fibrinolytic system. Activity of some factors of coagulation and fibrinolysis in the parietal thrombus of aortic aneurysm was determined using coagulative, fibrinolytic and caseinolytic tests. Retracted, blood clot was a comparative material. Tissue factor activity in the parietal thrombus of the aneurysm was above threefold higher and antiheparin activity was nearly twice higher in comparison to the blood clot. Activity of plasminogen activators in the parietal thrombus was higher than in the blood clot. The parietal thrombus contained fourfold more of the plasminogen. Antiplasmin activity in the thrombus was above twofold lower than in the blood clot. High activity of the tissue factor and substances neutralizing heparin may intensify the thrombus growth. Yet the thrombotic tendency may be balanced by a high activity of plasminogen activators and plasminogen.

Anticoagulative effect of pepsin

Anticoagulative effect of pepsin is observed in vitro when its concentration is 36 microM and higher. This effect is due to inhibition of fibrin monomer polymerization. Protamine abolishes anticoagulative effect of pepsin. Pepsin does not influence platelet aggregation induced by ADP and collagen.

Distribution, activity and concentration of cathepsin B and cystatin C in the wall of aortic aneurysm

Intensity of immunohistochemical reaction to cathepsin B is stronger and to cystatin C weaker in the wall of aortic aneurysm than in normal aorta. Localization of cathepsin B and cystatin C in the aneurysm wall is different from that in the control aorta, but activity and concentration of cystatin C in the aneurysmal wall is lower than in normal aorta. The parietal thrombus of aneurysm also shows high activity of cathepsin B. The obtained results point to participation of cathepsin B in degradation of aneurysmal structural proteins and in enlargement of the aneurysmal size.

[The role of proteolytic enzymes in apoptosis]

The literature review dealing with participation of proteolytic enzymes in initiation and execution of apoptosis was done. Cysteine proteases with Asp-X cleavage specificity, called caspases, play the main role in this process. The other proteases such calpains and proteasomes take also part in apoptosis. The proteases degrade proteins of cytoskeleton and structural proteins of nucleus, they also activate proendonucleases.

Cellular serine carboxypeptidases

The literature on serine carboxypeptidases of cells is reviewed. These proteases occur in the vacuoles of fungi and higher plants and in the lysosomes of animals and man cells. Physico-chemical properties, chemical structure, catalytic mechanism and substrate specificity of these enzymes are presented.

Cathepsin D and cathepsin L activities in aortic aneurysm wall and parietal thrombus

Deterioration of the aortic wall resulting in formation of aneurysms may be caused by increased activity of metalloproteases and lysosomal proteases. The aim of this work was the evaluation of cathepsin D and cathepsin L activities, and activities of inhibitors of cysteine cathepsins in the wall of aortic aneurysms and in parietal thrombus. Aortic aneurysms were obtained during operation. Aortas taken from organ donors and blood clots were used as control material. Activities of cathepsin D and cathepsin L in the aortic aneurysm wall and parietal thrombus were higher than in the control groups. The aneurysm wall showed lower activity of inhibitors of cysteine proteases than the normal aorta. Parietal thrombus had a higher level of cysteine protease inhibitor activity than blood clot. Cathepsin D and cathepsin L present in the aneurysm wall and in the parietal thrombus filling the aneurysm may act on proteins determining elasticity and mechanical resistance of arteries.

Activities of proteases in parietal thrombus of aortic aneurysm

Deterioration of the aortic wall resulting in formation of aneurysm may be evoked by increased activity of elastases, collagenases and lysosomal proteases. These enzymes come from macrophages and neutrophil granulocytes which are elements of the inflammatory reaction accompanying aneurysm. These cells may also come from parietal thrombus in the aneurysm lumen. The aim of this work was to determine activity of elastase, cathepsin G, collagenase-like Pz-peptidase and cathepsins A, B, C, D and E in the parietal thrombus of aortic aneurysm. The thrombus was obtained from the lumen of the aortic aneurysm of six patients during operation. Protease activities were determined using specific substrates at optimum pH. Retracted blood clot was a comparative material. The thrombus of aortic aneurysm showed two-five fold higher activity of elastases, collagenase-like Pz-peptidase and cathepsins A, D and G in comparison to the blood clot (P < 0.001). However, activity of cathepsins B, C and E in the thrombus was only slightly higher (P < 0.05). Prolonged effect of proteases coming from parietal thrombus on the aneurysm wall could evoke marked degradation of fibrillar proteins resulting in increase of aneurysm.

[Matrix metalloproteases (MMPS)]

Matrix metalloproteases (MMPs) are synthesized in the form proenzymes. They are activated in the process of limited proteolysis and non-enzymatically by active forms of oxygen. Activity of these enzymes is controlled by tissue inhibitors of metalloproteases (TIMPs).

[The effect of protein oxidation modification on protease-antiprotease balance and intracellular proteolysis]

This review describe the oxidative modification of proteins and its effect on the proteases and antiproteases activity. The changes in the proteolytic-antiproteolytic balance and the susceptibility of the protein substrates on proteolysis are also presented.

[Tissue factor pathway inhibitor (TFPI) and its role in pathology]

Tissue factor pathway inhibitor (TFPI) is an important regulator of blood coagulation. It was described as antyconwertin (AC), extrinsic pathway inhibitor (EPI) and lipoprotein-associated coagulation inhibitor (LACI). TFPI is a glycoprotein, which is mainly synthesized by vascular endothelial cells. The concentration of this enzyme in plasma is low (100 ng/ml). TFPI inhibits activity of factor Xa and complex FVIIa/TF. Changes TFPI activity play an important role in coagulation disorders and presently the function of TFPI in various kinds of diseases is discussed.

Cancer procoagulant--CP

A review of literature concerning cancer procoagulant (CP) has been carried out. This procoagulant directly activates coagulation factor X to factor Xa. Possibilities of utilising determinations of this activator in diagnostics and prognostics of the cancerous disease are discussed.

Extralysosomal degradation of proteins

Extralysosomal degradation of proteins is carried out by proteases complex (proteasomes), calcium dependent calpains, proteases of the rough endoplasmatic reticulum and proteases of the cellular membrane. It depends on a limited proteolysis and includes the main enzymatic proteins, hormones, growth factors and cytoskeletal proteins. Thus it plays an important regulatory role in the metabolism and formation of cellular structures.

Lysosomal cysteine proteinases and their significance in pathology

The lysosomal cysteine proteinases are synthesized in a form of pre-proenzymes. They are submitted to posttranslational glycosylation and phosphorylation. These modifications make possible transport the modified proteins into Golgi apparatus and into lysosomes. Some disturbances of transport which occur mainly in tumour cells result in an increase of these enzymes activities in cytosol and in intercellular compartment. The activity of cysteine proteinases is regulated by specific inhibitors (cystatin, kininogen) which exist in some tissues and body fluids. The evaluation of activity and concentration of proteinases and inhibitors is important in clinical diagnostics.

Plasminogen activators and plasmin in lung cancer

Urokinase plasminogen activator and plasmin contribute to detach neoplastic cells from solid tumor and facilitate the movement of these cells through interstitium and capillary walls as well as infiltration of the surrounding structures. Plasminogen activators inhibitors fulfill a regulatory function in these processes. Determining activity and concentration, finding subcellular, cellular and zonal localization of every component of plasminogen activation system has diagnostic and prognostic importance in different lung cancer types.

Proteolytic enzymes in proliferation and neoplastic metastases formation

Metalloproteases, plasminogen urokinase activator, plasmin and cathepsins enable the expansion of neoplastic tumors, leading to metastases formation. They cause neoplastic cells to detach from tumor, facilitate cell movement, implantation and participate in tumor vascularization. The regulation of these processes is accomplished during the synthesis and activation of proenzymes. Enzyme activity control is realized by their bonds with cellular membranes, and inhibitor action.

Tissue factor pathway inhibitor (TFPI)

Tissue factor pathway inhibitor (TFPI) is a plasma proteinase inhibitor. It is a 42 kD glycoprotein that consists of 276 amino acid residues which sequence is known. TFPI is synthesized by vascular endothelial cells and part of it is associated with glycosaminoglycans of these cells. In blood TFPI is found in a free-form (active) and in an associated with lipoprotein form (nonactive). TFPI directly inhibits activated factor Xa and then factor VIIa/TF complex. Decreasing TFPI activity facilitates an activation of blood coagulation and fibrin forming, increasing TFPI activity inhibits these processes.

Biological and diagnostic role of cathepsin D

Biosynthesis, posttranslating modifications, intracellular transport and activation of procathepsin D are discussed. Active cathepsin D evokes degradation of cellular and extracellular proteins and it also activates proenzymes, prohormones and growth factors and inactivates their active forms. Impairment of lysosomes in hypoxia or necrosis evokes transition of cathepsin D to cytosol and body fluids. Increase of cathepsin D content in cytosol also evokes enhancement of the synthesis rate observed among others, in neoplastic tissues and regenerating organs. Increase of cathepsin D content and activity in cytosol and blood serum is of essential diagnostic and prognostic importance in some pathologic conditions.

Activity and localization of cathepsin B, D and G in aortic aneurysm

The activities of cathepsin B, D and G, and their distribution in the walls of normal aorta and those of aneurysms of abdominal aorta were studied. The immunohistochemical reaction for these cathepsins was positive in the aneurysm wall both in the cells and in the extracellular matrix. It was more apparent than in normal aortas. The activities of cathepsin B, D and G in aneurysm were 1.5 times higher than in normal aortas. It may be suspected that besides the action of collagenases and elastases the cathepsins participate in an enhanced degradation of collagen and elastin fibers of aneurysm wall.

Activity of enzymes of various subcellular localisation in cytosol obtained after cell organelle precipitation at pH 5.0

Acidification to pH 5.0 of various organ homogenates prepared in 0.25 M sucrose causes aggregation of cell organelles. Aggregated organelles are removed through standard centrifugation. Cytosol obtained reveals only slight activity of membrane and lysosomal enzymes. The cytosol is useful for evaluation of changes in enzyme distribution in cell.

Collagen, elastin and glycosaminoglycans in aortic aneurysms

The walls of human abdominal aortas and atherosclerosis-induced aneurysms contain similar amounts of collagen. The quantitative ratio between collagens of various types of this protein does not differ significantly either, whereas solubility of the collagen in aneurysmal wall and its susceptibility to the action of EDTA are distinctly decreased. In contrast with collagen, the amount of elastin in aneurysms is significantly lower. Total amount of glycosaminoglycans slightly decreased as compared with that of normal tissue, but the ratio of particular compounds varies. The percentage of chondroitin sulphate is increased and that of heparan sulphate significantly decreased. The significance of these changes in pathogenesis of aneurysms is discussed.

Cathepsin D activity and protein degradation products in organs and blood during experimental declamping shock

Aortic cross-clamping in dogs for 60 min causes an increase in cathepsin D activity in the kidney, liver, lung, heart, skeletal muscle and the blood serum. It causes no changes in the content of protein and its degradation products of the examined organs, apart from the lungs, where the above parameters are higher. The intensity of the observed changes in the kidney and other organs does not depend on the level of aortic cross-clamping (above or below renal arteries).

Activity of membrane, cytosol and lysosome enzymes in organs and blood serum during declamping shock

The aim of the study was to evaluate the enzyme activity of cellular membranes (GGT), cytosol (ALT, AST) and lysosome (AP, AcP) in the cytosol, whole homogenate and blood serum during declamping shock, following release of abdominal aorta cross-clamping. The aorta was clamped for 60 minutes. An increase in GGT, AP and AcP activities in the cytosol and whole homogenate of the renal cortex, renal medulla, liver, lung, heart and the skeletal muscle occurs after declamping. Rise in the enzymatic activity, especially of acid phosphatase is higher when the aorta above renal arteries was clamped. However, its activity in the blood serum remains unchanged. Alterations in the distribution and the activity of the studied enzymes may indicate that aortic clamping damages the endoplasmic reticulum and lysosomal membranes. Yet, cellular membranes preserve their structural and functional integrity.