[The effect of methotrexate on activity of T-lymphocyte marker enzymes in patients with psoriasis vulgaris]. / Vplyv metotrexátu na aktivitu markerových enzýmov T-lymfocytov u pacientov so psoriasis vulgaris.

Radiochromatographic methods were used in order to ascertain the activity of adenosinedeaminase and purinnucleoside phosphorylase in lymphocytes isolated from the venous blood of 32 patients with psoriasis vulgaris in comparison with enzyme activities in 28 clinically healthy subjects. 11 selected patients with a severe form of psoriasis were subdued to therapy by means of methotrexate and its effect on the activity of these enzymes was investigated. Untreated patients yielded a statistically significant increase in the activities of adenosinedeaminase and purinnucleoside phosphorylase in comparison to the control group of healthy subjects. The increase rate of enzymatic activities abruptly reflexed the degree of affliction and spreading of the pathological process. Methotrexate significantly decreased the activity of both investigated enzymes in lymphocytes in patients with psoriasis. On the basis of the achieved results it is possible to justify the therapy of psoriasis by means of drugs which influence the metabolism of purines and at the same time they interfere the function of T-lymphocytes.

[The effect of colchicine and its derivatives on the activity of enzyme markers of T-lymphocytes]. / Vplyv kolchicínu a jeho derivátov na aktivitu markerových enzýmov T-lymfocytov.

Colchicine and its less toxic derivatives (demecolcine and deacetyl colchicine), in dependence on the concentration in the incubation medium, inhibited the activity of adenosine deaminase in the lymphocytes. All the three substances increased the level of cyclic adenosine monophosphate which has the ability of influencing the proliferation of T-lymphocytes. Colchicine and its derivates also inhibited the activity of purine nucleooxidophosphorylase, which, similarly as adenosine deaminase, is a marker enzyme of T-lymphocytes. The results obtained lead to the assumption that the mentioned preparations inhibit the function of T-lymphocytes.

The effect of allopurinol on lysosomal enzyme release.

Values of released enzymes from PMNL under resting conditions and after phagocytic stimulation in non-treated patients with gout were increased in comparison with healthy controls and hyperuricemic patients without joint involvement. Allopurinol, given to gout-patients for 3 weeks, had an inhibitory effect on PMNL lysosomal enzyme release from which was also observable after stimulation by opsonized zymosan. Similar results were obtained in experiments in vitro. The 1 hr preincubation of isolated polymorphonuclear leukocytes with allopurinol in concentrations from 0.01 mM-1 mM resulted in a dose-dependent decrease of enzymes released into extracellular space.

Activity of some lysosomal enzyme in rheumatoid and psoriatic arthritis.

In order to study the function of polymorphonuclear leukocytes in patients suffering from psoriatic and rheumatoid arthritis and psoriasis vulgaris the release of beta-glucuronidase, elastase and cytoplasmic lactate dehydrogenase was investigated. The life of polymorphonuclear leukocytes in rheumatoid and psoriatic arthritis is shorter. Polymorphonuclears from patients with psoriasis and psoriatic arthritis release, with as well as without phagocytic stimulation by zymosan, more lysosomal enzymes into extracellular space then cells of healthy controls. The total content of LDH and of lysosomal enzymes in leukocytes of patients suffering from all three forms of disease were not altered in comparison with the amount in PMNL of healthy subjects.

[Pathogenesis of gouty arthritis]. / Pathogenese der Gicht-Arthritis.

The urate crystal stands in the centre of the pathogenesis of gouty arthritis. External influences, such as changes of temperature and mechanical loads as well as factors, which lead to a short term change of the level of uric acid in the serum, such as alcohol, meals rich in purine, uricosurics and saluretics are, indeed, able to induce an attack of gout, but they are no obligatory prerequisite. The granulocytes are to be regarded as the second important prerequisite of the crystal arthritis. They become effective either via the process of phagocytosis or their cell membrane produces prostaglandins, the formation of which is evoked by electrostatic forces of the crystals. Mediators, such as kinins, Hageman's factor and complement are mainly responsible for the initial pain reaction, vasodilation and leukotaxis, lysosomal enzymes evoke the secondary changes at the joint.

Influence of a glycosaminoglycan polysulfate (Arteparon) on lysosomal enzyme release from human polymorphonuclear leukocytes.

In order to study the mechanism of action of a sulfated glycosaminoglycan (Arteparon) its influence upon the release of lysosomal enzymes from human polymorphonuclear leukocytes (PMNL) was investigated. Several fractions of tested glycosaminoglycan were used, differing in molecular weight (from 3,000 to 17,000). Human PMNL were incubated with zymosan particles opsonized with autologous serum. Preincubation with separate glycosaminoglycan fractions in concentrations 10(-3) M and 10(-4) M for 1 hr resulted in a significant activity decrease of released beta glucuronidase, neutral proteinase and myeloperoxidase. The concentration 10(-5) M was less active. Determination of total enzyme activities were made after cells (either incubated with tested glycosaminoglycan fractions for 1 hr or without incubation) were lysed by six freeze-thaw cycles. Sulfated glycosaminoglycan fractions inhibited all total enzyme activities. These results suggest direct inhibitory effect of tested drugs on lysosomal enzymes based on an interaction between inhibitor and enzyme.

Effect of levamisole on lysosomal enzyme release from polymorphonuclear leukocytes and intracellular levels of cAMP and cGMP after phagocytosis of monosodium urate crystals.

In order to study the influence of levamisole on lysosomal enzyme release, human polymorphonuclear (PMN) leukocytes were incubated with 0.5 mg/ml monosodium urate crystals. The release of neutral proteinase, beta glucuronidase, myeloperoxidase and lactic dehydrogenase as cytoplasmatic marker was measured. Preincubation of PMN with various concentrations of levamisole lasting 1 h resulted in a decrease of all enzymes released. Intracellular levels of both cyclic nucleotides--cAMP and cGMP--rose in PMN preincubated with levamisole, in comparison with untreated cells.

[Effect of levamisole on in vitro collagen synthesis]. / Wirkung von Levamisol auf die Kollagensynthese in vitro.

The effect of levamisole on collagen synthesis was studied. Tissue sections of skin of newborn rats were incubated with levamisole 10(-3) M up to 10(-5) M and 15C proline during 2 hours at 37 degrees C. Formation of soluble and insoluble collagen was inhibited only by the 10(-3) M levamisole. No effect was found with lower levamisole concentrations. Likewise an incorporation of 14C proline into collagen and collagen free proteins is inhibited. These results suggest that levamisole has not only its well-known immunostimulating action but also anti-proliferative effects.

The effects of colchicine and its derivates on the collagen biosynthesis in vitro.

Recent evidence shows that colchicine decreases collagen production and favourably influences some fibroproductive processes in experimental animal and clinical practice. In our study we investigated the influence of two colchicine derivates--demecolcine and desacetylcolchiceine--on the synthesis of collagen and non-collagen proteins in new born rat skin after the incubation of tissues slices with 14C-proline for 2 h. Collagen was separated in fractions soluble in either 0.45 M NaCl or 2% semi-carbazide that in an insoluble residue. Demecolcine (10(-3)--5.10(-5) M), desacetylcolchiceine (10(-2)--5.10(-4) M), as well as colchicine (10(-4)-10(-6)), inhibited the synthesis of soluble collagen, depending on the drug concentration in the incubation media. Higher concentrations of tested agents also decreased the formation of insoluble collagen. Significant inhibition of non-collagen protein synthesis was ascertained only in the presence of desacetylcolchiceine.