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In vitro incubation of human lymphocytes or a continuous human Jurkat T cell line with hydralazine (1-hydrazinophthalazine), a widely used antihypertensive agent, produced a nonspecific binding of various antibodies to the cells. This phenomenon was found to produce increases in staining of mitogen-stimulated and mitogen-unstimulated human lymphocytes and Jurkat cells with a variety of antibodies recognizing T and B cell antigens. The increase in nonspecific binding was greatest at 10(-2) M hydralazine, but was seen with concentrations as low 10(-7) M, which is comparable to the serum concentrations of patients prescribed hydralazine. The binding of antibodies is not connected with significant decreases in the cell viability. This property of hydralazine may cause misinterpretation of certain immunological tests employing the antibodies.

The effect of isoniazid on interleukin 2 production and interleukin 2-receptor expression by phytohemagglutinin-stimulated human T cells was investigated. High concentrations of the drug decreased interleukin 2 production while low doses (10(-5)-10(-6) M) produced a slight increase in interleukin 2 production. Isoniazid did not affect the expression of interleukin 2-receptors on the surface of T cells, except a slight decrease in cells exposed to high levels of the drug.

Human peripheral blood T cells or continuous T cell lines were treated with phorbol myristate (PMA), a direct protein kinase C activator. The effect of isoniazid on PMA-treated cells was investigated. It was found that low doses of isoniazid augmented proliferation of T cells treated with PMA or stimulated with PMA and phytohemagglutinin. Similar results were shown in the Jurkat cell line. There was no influence of isoniazid upon proliferation of PMA-treated HT-2 cells, interleukin 2-dependent cell line. The obtained results suggest that, at least one target mechanism of isoniazid is located in T cell activation pathway after protein kinase C activation.

The effect of dibutyryl guanosine cyclic monophosphate (db-cGMP) on proliferation of an interleukin-2 (IL-2)-dependent T-cell line was investigated. Dibutyryl cGMP added to HT-2 cell cultures without IL-2 or in the presence of an optimal IL-2 concentration (60 U/ml) had no effect on proliferation. The same amount of db-cGMP (10(-5)M) added to cultures in the presence of suboptimal amounts of IL-2 (3-6 U/ml) produced significant increases in proliferation. In contrast, db-cAMP caused substantial inhibition of HT-2 cells cultured with IL-2. Similar effects were observed using human T-cell blasts produced after 72 h stimulation with phytohemagglutin. These results suggest that cyclic GMP may play a role in the cellular response of IL-2 responsive cells to IL-2.

Liver fibrosis in rats was induced by repeated subcutaneous injections of carbon tetrachloride. Total collagen, soluble and insoluble collagen fractions as well as type I and type III collagen content in the liver were subsequently measured over a 3-18 week period. Liver collagen was found to increase exponentially during this time. Insoluble collagen accumulated more rapidly than soluble forms, and the accumulation of type III collagen was relatively greater than type I collagen. Changes in specific liver enzymes were also observed. Collagenase, collagenolytic cathepsin and collagen peptidase activities all increased. Levels of collagen-degrading enzymes increased rapidly during the first weeks of fibrosis-induction, and were followed by a more gradual increase during the remainder of the study.

Clinical and experimental studies have previously shown the effect of thyroid state on the activity of non-specific phosphohydrolases. This research was undertaken to determine the influence of thyroid hormones on the activity of specific phosphohydrolase-5'-nucleotidase. The activity of 5'-nucleotidase was estimated in blood serum, tissues (liver, kidney, lung, brain) and mitochondrial fraction of liver of normal, methylothiouracil-induced hypothyroid and thyroxin-induced hyperthyroid rats of Wistar strain. The experiments have shown that the hypothyroid state induced decrease of the activity of 5'-nucleotidase in all studied materials, and on the contrary, the hyperthyroidism induced the increase of the enzyme activity. The hypothetical mechanism of the effect of thyroid hormones on the processes of feed back regulation of oxydative phosphorylation and delivery of substrates and oxygen is presented. The key role of 5'-nucleotidase in this mechanism is discussed.

Collagen metabolism was studied in patients with viral hepatitis, chronic hepatic disorders as well as under experimental conditions, in rats with carbon tetrachloride-induced hepatic fibrosis. Changes in serum hydroxyproline, hydroxylysine and collagen-like protein levels, and collagen peptidase activity were observed in clinical investigations. An increase of collagen content and collagen-glycosaminoglycan interactions were found in the liver samples of rats with the hepatic fibrosis. An increase of collagenase activity in the course of fibrosis is due to an elevated biosynthesis of the enzyme de novo as well as to a decreased content of inhibitors. The activity of collagen peptidase and collagenolytic cathepsin were increased, and it was suggested that an increase of collagen degradation in the liver was a self-defensive mechanism against fibrosis but insufficient to protect the organ against it. This was caused probably by changes in susceptibility of collagen to degradating enzymes in the course of chronic hepatic disorders.

Haematological studies were carried out in hydralazine-induced collagen-like syndrome in guinea pigs. 37.5 per cent of animals were found to be LE-positive. It was found that long-term administration of hydralazine caused a decrease of erythrocyte count, a decrease of haemoglobin concentration and a decrease of haemoglobin content in individual red blood cell as well as a decrease of a single erythrocyte volume. A significant leukopenia was shown in LE-positive subgroup of hydralazine-treated guinea pigs. The obtained results confirmed the similarity of hydralazine syndrome to systemic lupus erythematosus.

Collagen fractions content and level of collagen catabolites in body fluids were determined in normal, hypo- and hyperthyroid guinea pigs. An increase of urinary excretion of hydroxyproline and hydroxylysine as well as concentration of these amino acids in blood serum was found in hyperthyroidism, and a decrease was shown in hyperthyroid guinea pigs. Hyperthyroidism stimulated an increase of neutral-salt-soluble and acid-soluble collagen in skin and liver, and a decrease of insoluble collagen in skin as well as increase of all collagen fractions in bone samples. Hypothyroidism induced a decrease of all collagen fractions in skin and liver, and an increase of acid-soluble and insoluble collagen in bone samples.

In 45 patients suffering from acquired valvular heart disease (a.v.h.d.) and in 20 controls blood serum levels of copper (Cu2+), ceruloplasmin (Clp), hydroxyproline (Hypro), hydroxylisine (Hyliz), collagen-like protein (Col-p), and daily urine excretion of Cu2+, Hypro, Hyliz and glycosamino-glicans (GAG) were determined. The comparison of the obtained mean values has shown that blood serum levels of Cu2+, Clp, Hypro, Hyliz, Col-p in the studied patients were statistically significantly higher than those found in controls, and the values of daily urine excretion of Cu2+, Hypro, Hyliz, GAG behaviour were similar. There were no significant differences between active and inactive processes and between infective and rheumatic endocarditis excluding GAG urine excretion. These elevated collagen degradation products provide evidence for disturbed collagen metabolism and confirm our previous biochemical, histopathological and ultrastructural examinations of connective tissue in patient with a.v.h.d. They also indicate that general collagenopathy might be the primary cause of a.v.h.d.

The activity of selected lysosomal hydrolases ( (beta-galactosidase, beta-N-acetylglucosaminidase, beta-xylosidase, alpha-mannosidase, alpha-fucosidase) was determined in the blood serum of patients with systemic lupus erythematosus (SLE). An increased activity of all the enzymes studied was found as compared to control subjects. Presumable mechanisms of the observed changes are discussed. It is suggested that the studied enzymes may be responsible for the desintegration of the connective tissue ground substance in SLE.

The collagens are a group of the connective tissue proteins widely distributed in human and animal body. The collagens together with other components of the tissue form a complex regulatory system, and are subject to hormonal control. The present paper reviews the effect of thyroid hormone and thyroid-stimulating hormone (thyrotropin) on collagen. Thyroid hormone influences collagen biosynthesis and degradation, and this effect is responsible for various pathophysiological phenomena, including alterations in urinary excretion of hydroxyproline and hydroxylysine, hyperthyroid acropachy, pretibial myxedema, impaired wound repair and other fibrosis-associated processes as well as a tadpole tail resorption in amphibians. Thyrotropin also directly affects the connective tissue, and is responsible for exophthalmos caused by acumulation of certain components of the tissue in retrobulbar space. Collagen fibres are present in the thyroid gland, and take part in the embryogenesis of the gland.

Azathiprine (0.25 mg/100 g body wt.) and cyclophosphamide (0.2 mg/100 g body wt.) were administered to guinea pigs, orally every day during 4 weeks. Azathioprine caused a decrease in total collagen content in skin, liver and bone and decreased hydroxyproline and hydroxylysine concentration in blood serum, and urinary excretion of collagen catabolites. No effect of cyclophosphamide on total collagen in skin and liver was observed. An increase in collagen content in bone in cyclophosphamide-treated guinea pigs was found. A decrease of hydroxyproline and hydroxylysine in blood serum and urine was observed after cyclophosphamide treatment. The results support the view that cytostatic drugs inhibit collagen metabolism, and azathioprine significantly affects collagen biosynthesis, and cyclophosphamide influences inhibition of catabolic processes of collagen.

Activity of collagen peptidase was measured in patients with myocardial infarction. Determinations were carried out 1, 3, 6, 9, 14 and 21 days after admission to the hospital. A decrease of activity was observed between the 6th-21st day of the disease. A low correlation with serum aminotransferases was found. It is concluded that estimation of serum collagen peptidase does not reflect accumulation of collagen in the healing heart muscle.

Adult rats were given water with sodium fluoride (10 mg/l) during 7 weeks before pregnancy, during pregnancy and after the delivery. The born rats were treated in the same manner and were investigated 1, 2, 4 and 6 months after birth. It was found that exposure to sodium fluoride stimulated an increase of hydroxyproline and hydroxylysine concentration in serum and the urinary excretion of these catabolites. A decrease of soluble and insoluble collagen was shown in skin and lungs of exposed animals as compared with controls. The decrease of collagen in tissues was not age-dependent.

An increased level of glycoproteins (seromucoid, protein-bound hexoses, protein-bound hexosamines, protein-bound sialic acids) was found in the blood serum from patients with rheumatoid arthritis (RA) as compared with healthy individuals. Higher glycoprotein content was observed in the seropositive RA patients than in the seronegative ones. Higher levels of glycoproteins was also observed in the synovial fluid from seropositive RA patients than in the seronegative ones.

Prolonged administration of 1-hydrazinophthalazine (hydralazine) to guinea pigs stimulated the development of collagen disease-like syndrome. Inflammatory changes were found in the heart, kidneys and skin.

Morphological studies of the heart muscle were carried out in healthy rats as well as treated with hydralazine or binazine after administration of adrenaline, noradrenaline, isoprenaline, regitine or propranolol. Hydrazinophtalazines (25 mg/kg body wt, daily) were given during 7 months. After discontinuation of this treatment the drugs were administered during 15 days. Evident changes (e.g. inflammatory infiltrations, focal necrosis and fibrosis) were found after administration of noradrenaline, adrenaline or isoprenaline. No differences were found in the reactivity to catecholamines in healthy and hydrazinophtalazine-treated rats.

Haematological investigations of peripheral blood and bone marrow were performed in rabbits receiving hydrazinophthalazines (hydralazine or binazin) with or without simultaneous hyperimmunization by means of repeated injections of bovine albumin. It was found that long-term administration of hydralazine caused appearance of LE factor in the serum and LE cells in blood. Less evident changes were caused by Binazin administration. Hyperimmunization caused weaknening of the effects of hydralazinophthalazines. Haematological investigations demonstrated hypochromic anaemia.

Guinea pigs were exposed to nitrogen dioxide in concentration of 2 mg/m3 (8 hrs. daily, 180 days). Control group inspired fresh air. Collagen fractions were estimated in skin and assayed as hydroxyproline concentration. An increase of total collagen content, due to on increase of salt-soluble collagen fraction was found in the skin of the exposed animals, while a simultaneous decrease of insoluble collagen content was observed.

High serum levels of total hydroxyproline (Hyp) and hydroxylysine (Hyl) in patients with acute viral hepatitis were found to be due to a marked increase of the peptide-bound form of these aminoacids. The concentrations of free Hyp and Hyl were only slightly changed. The levels of serum Hyp and Hyl were higher in patients with bilirubin concentration, and decreased during recovery.

A collagen-like syndrome was produced by a long-term administration of 1-hydrazinophthalazine (hydralazine) to guinea pigs. The results obtained indicate that hydralazine-induced collagen-like syndrome stimulated an increase of the concentration of perchloric acid-soluble proteins, protein-bound hexoses, protein-bound-hexosamines and sialic acids in blood serum as well as urinary excretion of glycosaminoglycans. The increase of serum glycoproteins is not connected with non-specific changes in total protein level. No biochemical differences were found in the parameters studied between subgroups (LE-positive and LE-negative) of hydralazine treated animals.

Immunomodulatory properties of copper were investigated. Human T cells, isolated from blood of healthy donors, were stimulated with phytohemagglutinin and cultured in vitro. It was found that copper sulphate depressed T cell proliferation when added in concentration of 10(-3) M. A slight increase in the T cell proliferation was shown in presence of 10(-5) M of copper ion while 10(-7)-10(-9) M had no effect on proliferation. Production of interleukin 2 by human T cells was depressed by all investigated doses of copper. The obtained results suggest the direct toxicity of copper on T cell activation.