Beneficial effect of combined spironolactone and quinapril treatment on thrombosis and hemostasis in 2K1C hypertensive rats

A strong correlation between raised aldosterone levels and increased risk of thrombotic disorders has been provided. Clinical studies have demonstrated the benefits of the addition of the aldosterone receptor antagonist to the standard therapy with angiotensin-converting enzyme inhibitor in the reduction of cardiovascular events in patients. We suggest that the benefits of this dual renin-angiotensin-aldosterone system (RAAS) blockade may be related to the drug's effects on the hemostatic and oxidative balance. Thus, we investigated the effect of combined spironolactone (SPIRO) and quinapril (QUIN) administration on thrombosis, hemostasis and oxidative stress in hypertensive rats. A two-kidney, one-clip model of renovascular hypertension in Wistar rats was used. QUIN, SPIRO, or QUIN + SPIRO were administered for 10 days. Venous thrombosis was induced by vena cava ligation. Thrombus weight and incidences of thrombosis were assessed. Bleeding time, platelet adhesion, tissue factor (TF), tissue plasminogen activator (t-PA), plasminogen activator inhibitor (PAI-1), thrombin activatable fibrynolysis inhibitor (TAFI), malonyl dialdehyde, and hydrogen peroxide plasma levels were assayed. Aortic expression of NADPH oxidase and superoxidase dismutase were measured. We observed significant RAAS activation associated with hypercoagulability and oxidative stress augmentation in renovascular hypertensive rats. Thrombosis was reduced only in rats treated with QUIN + SPIRO. In all groups, decreases in TF, PAI-1, and TAFI levels were observed, however in the QUIN + SPIRO group those changes were more pronounced. The inhibition of platelet adhesion was also stronger in rats treated with QUIN + SPIRO. The oxidative stress parameters were markedly reduced in rats treated with QUIN or SPIRO, although the most evident changes were observed in the QUIN + SPIRO group. Dual RAAS blockade with aldosterone receptor antagonist and angiotensin-converting enzyme inhibitor provides additional benefits for experimental thrombosis associated with the antiplatelet, anticoagulative, profibrinolytic, and antioxidative effects in renovascular hypertensive rats.

[Endothelial action of aldosterone--therapeutic implications from basic and clinical research]

Aldosterone is the main hormone regulating the water and electrolyte balance of the organism. It is produced and secreted by zona glomerulosa of the adrenal gland cortex, cardiomyocytes as well as by cells of the blood vessel wall. The article is the review of contemporary knowledge of the role of aldosterone in physiology and pathophysiology of cardiovascular system. The authors describe the nuclear and membrane mechanisms of endothelial action of aldosterone, especially their role in the development of cardiovascular system pathologies. New therapeutic indications for aldosterone receptor antagonists are also discussed.

[Hypophosphatemic oncogenic osteomalacia]

The first case of oncogen osteomalacia in Hungary is reported, to draw the attention of the medical profession to it and to present the new data about its pathomechanism. Pathological hip fracture caused by hypophosphataemic osteomalacia due to isolated renal phosphate wasting was found in a previously healthy 19 years old sportsman. In spite of daily 1.5 micrograms calcitriol treatment and phosphate supplementation, hypophosphataemia persisted for 13 years and he needed regular indometacin medication for his bone pain. During that time an 1.5 cm gingival tumour was found and radically removed. The serum phosphate level returned to normal in a few hours after the operation (preoperative 0.51, after 2, 4 and 8 hours 0.61, 0.68 and 0.79 mmol/l respectively), and remained normal without calcitriol. The histological examination showed epulis with fibroblast and vascular cell proliferation, which has never been previously reported in connection with oncogenic osteomalacia. The pain resolved after 3 months and the bone density became normal in one year. Oncogenic osteomalacia must be considered in every case presenting with atypical hypophosphataemic osteomalacia. Careful dental examination is needed also in the course of search for the underlying tumour. Every tumour-like growth, even the common epulis, has to be operated radically and serum phosphate monitored in the postoperative period in all such cases.

[Diagnostic possibilities in gastric leiomyoma in relation to two of our cases]

Two cases of rare, benignant gastric tumors are reported. The suggest that while in the diagnosis of tumors with a mucous membrane involvement endoscopy has doubtless a leading role, tumors not infiltrating the mucous membrane are usually better recognizable by radiological (ultrasonography, computer tomography and double contrast x-ray) methods. An appropriate diagnosis followed by surgical removal of the tumor might result in a complete healing of the patient.

[Diagnosis of Meckel diverticulum, containing ectopic gastric mucosa", by studying small bowel passage]

Radiological diagnosis of Meckel diverticulum is a difficult task. Here we report a patient with hereditary sphaerocytosis who complained of a chronic periumbilical pain and in whom antegrade barium enema suggested Meckel diverticulum. The diagnosis had been proven both surgically and histologically. This observation indicates that so called traditional x-ray still has its role even in the era of modern (and expensive) radiology.

Elastic properties of passive leukemic white blood cells

The key role of leukocytes (WBC) in pathologic alterations of microcirculation was repeatedly described in the literature. The aim of this study was to compare the mechanical characteristics of WBC of 4 healthy donors and 6 patients suffering from chronic myeloid leukemia (CML). The elastic properties of individual leukocytes in the passive state were studied by the micropipette technique (aspirating pressure delta P = 100 divided by 250 Pa; internal pipette radius Rp = 1.4 divided by 2.6 microns). The passive elastic rigidity of WBC (PER) from 30 cells/donor was characterized by the amplitude of their steady-state deformation (Dp) normalized for the pipette radius (Rp) against the stress parameter delta P * Rp. The effect of a CML-therapy with cytostatics was monitored by way of differential blood counts. A significantly higher rigidity of healthy lymphocytes (PER = 349.7 +/- 125.9 microN/m; n = 45) than that of polymorphonuclear granulocytes (PER = 226.5 +/- 86.7 microN/m; n = 62) was seen which appears to result from their large, solid nucleus. Control leukocytes have a significantly higher rigidity than leukemic WBC. Leukemic granulocytes (PER = 155.1 +/- 67.7 microN/m; n = 61) and lymphocytes (PER = 134.3 +/- 51.9 microN/m; n = 62) do not differ significantly in their values of rigidity.

[Analysis of the function of the circulatory system and its components based on rheologic viewpoints]

The authors analyse from hemorheological viewpoint the vascular system and the blood, its special circulating medium. The most important anatomical and physiological characteristics are referred to completing them with the presentation of the basic rheophysical parameters and correlations. Factors determining the viscosity of blood are specified and discussed separately. The definition based on literary data according to which the viscosity of blood is greater with lower circulation gradient and lower--in view of the non-Newtonian character of bloodat a higher rate is discussed. The significance of the adaptability of blood cells is emphasized in the determination of the rheological characteristics of blood.

[The roots, concept, subject, and history of hemorheology, current tasks and further perspectives]

The authors give a reviewing summary on the origin of hemorrheology and its relationship to basic sciences. Its concept is defined, recognitions and endeavours of this character in the history are analysed and followed up. The names of the scientists whose merit was significant in the creation of rheology-hemorrheology are presented referring briefly to the main points of their activity. The general, international situation of the discipline is outlined, countries leading and determining its development are indicated and the main points of the situation in Hungary are described. The examinational fields of clinical hemorrheology are presented, describing briefly the future directions.

Effects of preparative procedures and of cell activation on flow of white cells through micropore filters

Using newly developed filtration techniques to analyse the flow resistance of white blood cells (WBC), the effects of preparative procedures and of various treatments (including activation) have been tested. Flow rates of WBC were measured using both 5 and 8 micron pore filters. It was found that EDTA was the anticoagulant of choice over heparin and sodium citrate, and that calcium-containing media should be avoided because they promoted cell-cell aggregation. Exposure to density separation media did not significantly alter filtration rates, but storage of prepared WBC for even 1 h caused deterioration in flow. Storage of whole blood before preparation of the WBC had a much lesser effect. Storage appeared to be linked to cell activation, and use of the activating agents phorbol ester (PE, 4.5 x 10(6) M/l) and f-methyl-leucyl-phenylalanine (FMPL, 10(-7) and 10(-9) M/l) also increased WBC resistance to pore transit. The effect of PE was greater, causing rapid pore blockage, but was non-specific, while the lesser effect of FMLP was restricted to granulocytes and was concentration dependent. Cell volume was increased by these agents, but measurement of the filterability of hypotonically swollen granulocytes showed that volume changes alone only partly explained the activation effects. These results suggest that activation in vivo would have a significant rheological effect, detectable by filtration methods.

Methods and theory for analysis of flow of white cell subpopulations through micropore filters

Methods have been developed for analysing the resistance of WBC to flow, by measuring their transit rates through 5 and 8 microns pore filters at constant pressure. Unfractionated WBC and separated subpopulations have been compared. For either pore size, lymphocytes exhibited least resistance to flow, followed by granulocytes, with monocytes being most resistant. A theoretical model, which represents WBC suspensions as made up of three particle types (a relatively fast and a relatively slow population, plus a pore blocking population) adequately describes the data for flow rate versus volume filtered. For 5 microns pores, this theory indicates that a majority of WBC have transit times approximately less than 0.5 s. Unfractionated and mixed mononuclear samples contained a proportion of particles with transit times an order of magnitude longer, whereas, for granulocytes, no slow flowing population was evident. Removal of monocytes by plating out, reduced the proportion of the slow particles in the mononuclear preparation. Unique values for transit times could not be determined for 8 microns pores, but it could be concluded that the great majority of WBC made a very quick transit, with the flow becoming dominated by a small number of much more resistant cells. Simple flow parameters (initial relative flow rate and slow particle resistance) are described which characterize these two populations. Both 5 and 8 microns pore data indicated that few cells became permanently trapped within pores.