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PubMed1978

Effects of colchicine on osteoblast in rat: an ultrastructural study.

The present study was an attempt to investigate the effects of colchicine on the ultrastructure of rat osteoblasts with special reference to the microtubular function in vivo. Rats were killed at intervals of 2, 4, 8, 12 and 24 hours after the colchicine injection (0.1 mg per 100 g of body weight, subcutaneously). At 2 and 4 hours after the injection, the secretory granules and small vesicles accumulated in the Golgi area of the osteoblasts. The dilated spherical cisterna of the rough endoplasmic reticulum and the large vacuoles appeared, being located in the periphery of the cell. Microtubules were rarely found in the cytoplasm. Small masses of microfilaments of 80 to 110 A in diameter were found also in the cytoplasm. According to the special staining for collagen, it was indicated that the contents of the secretory granules might be collagen-like materials. At 8 hours after the injection, the shape of the osteoblasts transformed to a round profile and the autophagic vacuoles increased in the cytoplasm. At 12 and 24 hours after the injection, the osteoblasts seemed to be destroyed by the breakdown of the plasma membrane and by the increase of the autophagic vacuoles. It is suggested that colchicine affects the secretory process of the bone matrix and the cytoskeletal system of the osteoblasts by interfering with the structure and the function of the microtubules and colchicine also interferes with the function of the plasma membrane followed by the destruction of the osteoblasts.

Animals↗
PubMed1988

Linkages between the effects of taxol, colchicine, and GTP on tubulin polymerization.

A comparative study has been carried out of the effects of taxol on the polymerizations into microtubules of microtubule-associated protein-free tubulin, prepared by the modified Weisenberg procedure, and of the tubulin-colchicine complex into large aggregates. Taxol enhances, to a much greater extent, the stability of microtubules than that of the tubulin-colchicine polymers so that, with highly purified tubulin, assembly into microtubules takes place at 10 degrees C, even in the absence of exogenous GTP. The polymerization of tubulin-colchicine requires both heat and GTP, and the process is reversed by cooling. These results indicate that in both systems polymerization is linked to interactions with taxol and GTP, the interplay of linkage free energies imparting the observed polymer stabilities. In the case of microtubule formation, the linkage free energy provided by taxol binding is approximately -3.0 kcal/mol of alpha-beta-tubulin dimer, whereas this quantity is reduced to approximately -0.5 kcal/mol in tubulin-colchicine, indicating the expenditure of much more binding free energy in the latter case for overcoming unfavorable factors, such as steric hindrance and geometric strain. The difference in the effect of GTP on the two polymerization processes reflects the respective abilities of the bindings of taxol to the two states of tubulin to overcome the loss of the linkage free energy of GTP binding. Analysis of the linkages leads to the conclusions that taxol need not change qualitatively the mechanism of microtubule assembly and that tubulin with the E-site unoccupied by nucleotide should have the capacity to form microtubules, the reaction being extremely weak.

Alkaloids↗
PubMed1989

Structural and biochemical comparison of the anti-mitotic agents colchicine, combretastatin A4 and amphethinile.

The novel agents amphethinile and combretastatin A4 are shown to be very similar to colchicine in their interactions with purified tubulin. All three agents can inhibit tubulin assembly at similar treatment levels and have comparable affinity constants for tubulin. Amphethinile and combretastatin A4 are capable of displacing colchicine but not vinblastine from tubulin. A comparison of the structures of these agents shows that whereas colchicine and combretastatin A4 contain a trimethoxybenzene group (a moiety also found in other colchicine-like agents such as podophyllotoxins and steganacin) no obvious similarity is seen for amphethinile. The three-dimensional structures of these agents, determined from either crystallographic data or by energy minimization procedures, show, however, that all three agents consist of two planar, or almost planar, ring systems which are tilted with respect to each other. Using computer graphic techniques it can be shown that their ring systems are superimposable and that the planar sections of each molecule are at an angle of 50-60 degrees to each other. It is proposed that the angular bicyclic structure of these agents is one determining factor for their efficient binding to tubulin.

Animals↗
PubMedDate not supplied

Colchicine in therapy. State of the art and new perspectives for an old drug.

Colchicine is the most specific treatment in acute gouty attacks. In several European countries, oral colchicine is still used for routine treatment of acute gout. Its selectivity is used as a diagnostic tool. It is also active in the treatment of acute crises of chondrocalcinosis and more occasionally of other arthritic crises (e.g. sarcoidosis). Colchicine appears to be the necessary adjuvant prophylactic drug when starting a hypouricemic treatment with uricosuric or uricolytic drugs for avoiding acute gouty crisis due to sudden mobilisation of the uric acid pool. Besides gout, colchicine is the drug of choice for treating familial mediterranean fever. It appears to be helpful in the treatment of Behçet's disease. It seems also useful for treating fibrosing conditions such as liver cirrhosis and scleroderma. As an adjuvant therapy, it helps treating dermatological disorders which are associated with leucocyte migration as an essential pathogenic factor (e.g. psoriasis, dermatitis herpetiformis, necrotising vasculitis ...). It has been advocated as an adjuvant therapy in malignant diseases as a support in radiotherapy and as an useful drug in various other diseases where it has been tried occasionally (e.g. Paget's disease of the bone, idiopathic thrombocytopenic purpura, disc syndrome). This very old drug remains a modern therapeutic agent.

Arthritis, Gouty↗
PubMed1987

Transplantation of dentate granular cells after lesion of the dentate area by colchicine.

Colchicine selectively eliminated granular cells of the dentate area, and evoked potentials could no longer be recorded after perforant path stimulation. Colchicine treated rats were unable to learn a conditioned reaction via perforant path stimulation. The aim of this work was to investigate whether colchicine damaged granular cells could be replaced by grafting neonatal dentate area neurons. After injection of suspended granular cells no satisfactory development of grafted cells was seen, whereas granular cells of solid grafts did develop well, and a moderate reinnervation of the CA3-sector by mossy fibers sprouting out of the grafted cells was observed. In principle it is possible to replace colchicine damaged dentate granular cells by grafts in a few segments of the hippocampal formation. A total reconstitution of the damaged dentate area, including the mossy fiber system, will need a fundamental optimisation of the grafting technique used.

Animals↗
PubMed1987

[Successful therapeutic effect on periodic disease with the intermittent use of colchicine].

The continuous application of colchicine reduces considerably the incidence of the paroxysms in patients with periodic disease. A patient is described, a Bulgarian, with periodic disease with a duration of 40 years (family Mediterranean fever), successfully treated with intermittent application of colchicine according to a schedule for the last 3 years. The evolution of the clinical manifestations was followed up as well as the absence of effect by the corticosteroid therapy applied before. The intermittent application of colchicine, in this case, prevents totally the paroxysms with high temperature and pain in abdomen, chest and joints with a considerable smaller amount of the drug applied. The intermittent application of colchicine should first be tried in the treatment of patients with periodic diseases.

Colchicine↗
PubMedDate not supplied

The effect of colchicine on the development of experimental atherosclerosis in rabbits.

The effect of colchicine on the course of experimental atherosclerosis was investigated in rabbits receiving for 3 months a high-lipid diet (HLD) in addition to the basal diet. Colchicine was given in a dose of 0.2 mg/kg ip twice a week. An evident antiatherosclerotic action of colchicine was demonstrated both by macroscopic and microscopic investigation of the aorta. The level of blood total lipids was significantly depressed, and the level of triglycerides was back to normal. The content of total lipids in liver homogenates was similar to that in the controls. A significant decline in the fibrinogen concentration in the blood of rabbits receiving colchicine was also found.

Animals↗
PubMed1987

Colchicine in acute gout. Reassessment of risks and benefits.

Colchicine is an effective and relatively specific treatment for acute gout and has a long, venerable history. Serious toxic reactions to colchicine could be prevented if guidelines for its use were followed strictly, but because of its relatively infrequent use and conflicting recommendations, considerable toxic effects might occur and still be undetected by passive surveillance. A review of a teaching hospital's four years' experience showed two deaths (2% incidence) due to inappropriate use. Colchicine has the smallest benefit-to-toxicity ratio of drugs that are effective for acute gout. This article gives specific recommendations for the use of colchicine in different clinical settings.

Administration, Oral↗
PubMed1985

Effect of colchicine on atherosclerosis. I. Clinical and biological studies.

The effect of colchicine was studied in 51 hypertensive subjects with several other vascular risk factors. Colchicine was administered for 3-4 months in a daily dose of 1 mg per os. The treatment did not change the lipid content in the blood and in skin biopsies, and had no effect on systolic and diastolic blood pressure. On the contrary, colchicine treatment significantly improved the conjunctival biomicroscopy score, the duration of the dicrotic wave and the peripheral resistance index. The results show the improvement of the microcirculatory parameters (elasticity of arteries) without changes of serum and tissue lipid parameters in the patients treated with colchicine.

Adult↗
PubMed1979

Management of necrotizing vasculitis with colchicine. Improvement in patients with cutaneous lesions and Behcet's syndrome.

Six patients with necrotizing vasculitis were treated with oral colchicine as part of an open study. Four patients with cutaneous vasculitis and normal levels of serum complement and one patient with vasculitis associated with Behcet's syndrome demonstrated clinical improvement while receiving colchicine. One patient with cryoglobulinemia, hypocomplementemia, and cutaneous vasculitis showed no response to colchicine therapy. In three patients, clinical improvement persisted after its withdrawal. Colchicine may be effective in controlling cutaneous necrotizing vasculitis and Behcet's syndrome through its effect on polymorphnuclear leukocyte function.

Administration, Oral↗
PubMedDate not supplied

Long-term evaluation of colchicine in the treatment of scleroderma.

Fifteen patients with PSS, 4 with CRST syndrome, and 4 with localized scleroderma have been treated with colchicine at the maximum tolerated individual doses for an average of 39 months (range 19--57). All but 2 of the 19 patients with generalized scleroderma and 3 of those with localized scleroderma improved. Patients who had had scleroderma for less than 5 yr when begun on colchicine, and those who received total doses of colchicine of more than 1,438 mg, scored a significantly higher mean response index than those with longer disease duration, or those who received less colchicine.

Adult↗
PubMed1978

[Changes in the endomembrane system and mitochondria of cultured chick fibroblasts upon application of colchicine and following its withdrawal].

After the administration of colchicine (5 mcg/ml) into nutritive medium of primary tissue culture there is a remarkable decrease in the volume and number of fibroblast-membrane organoids during the first 3 hours. The removing of colchicine-damaged fibroblasts into the medium without colchicine leads to the renewal of the most of intracellular membranes during the following 24 hours. Probable reasons and mechanisms of colchicine-induced alterations are discussed.

Animals↗
PubMed1981

Effect of colchicine on the Golgi apparatus and on GERL of rat jejunal absorptive cells. Ultrastructural localization of thiamine pyrophosphatase and acid phosphatase activity.

Ultrastructural localization of thiamine pyrophosphatase (TTP) and acid phosphatase (AcPase) activity was performed on jejunal absorptive cells of rats pretreated with the antimicrotubular agent colchicine and of control animals. Demonstration of TPP activity showed that most of the dislocated Golgi stacks after colchicine application lacked positively staining cisternae of the mature side. This cytochemical finding is in agreement with the morphologically demonstrable changes of the Golgi stacks resulting in a loss of polarity and give evidence for a colchicine-induced deficiency of the Golgi apparatus. The cytochemical localization of AcPase activity showed deposits of reaction product over lysosomes and GERL and demonstrated a dislocation of GERL occurring concomitantly with the changes of the Golgi apparatus. The antimicrotubular effect of colchicine is well documented; thus the morphological and cytochemical changes of the Golgi apparatus and of GERL might be due to a disturbed microtubular function after application of this agent suggesting an influence of microtubules in the maintenance of the integrity of these organelles. This hypothesis includes the possibility of an involvement of microtubules in formation and differentiation of Golgi stacks and GERL as well as a kind of "skeletal"function being responsible for their characteristic structure and fashion.

Acid Phosphatase↗
PubMed1980

Therapeutic trials with oral colchicine in psoriasis.

Twenty-two psoriatic patients were treated orally with the antichemotactic agent, colchicine, at a dosage of 0.02 mg per kg per day for a duration of 2-4 months. Complete clearing or marked improvement were noted in 8 of the 9 patients, in whom thin papules and thin plaques were the predominant type of lesion. Much less favorable results were obtained in patients with chronic, stable, thick plaque-type disease, although decreased scaliness, erythema and infiltration and marked diminution of the pruritus were observed in almost all of the cases. A considerable improvement of the joint pains was noted in each of the 8 patients who suffered from arthralgias. Five additional patients with extensive, chronic, stable plaque-type psoriasis were given oral colchicine immediately after complete clearing of their skin lesions with Goeckerman's method or with methotrexate. Four of them continued to take colchicine for 8-9 months and during that time they remained free of significant skin disease. These findings lend support to the hypothesis that the migration of the activated psoriatic neutrophils into the skin could be an important factor in the initiation and possibly also in the perpetuation of the psoriatic lesions. Closely controlled, long-term studies conducted in large numbers of patients are warranted in order to determine the exact therapeutic role of oral colchicine in the long-term management of psoriasis.

Administration, Oral↗
PubMed1981

[Lingual taste buds following application of colchicine to the glossopharyngeal nerve in the rat].

Dissection of the glossopharyngeal nerve and application to it of colchicine that blocks axoplasmic drug transport were performed to study the effect of the nerves on the taste buds of foliate lingual papillae. It was observed that colchicine application to the nerve gave rise to destruction of the taste buds. The process of destruction proceeded more slowly as compared to that induced by nerve dissection. Colchicine application led to changes in the protein spectrum of the epithelium of foliate papillae. The absence of changes in the protein spectrum of the epithelium of foliate papillae and the presence of nerve fibers in the epithelium of the taste buds on exposure to colchicine provide evidence against its direct toxic effect on the taste buds, giving rise to their destruction. The changes seen in the taste buds result from the blocked transport of factors that participate in neurotropic control of the taste buds.

Animals↗
PubMed1983

The effect of intra-articular colchicine on the knee joint of the rat.

The effect of intra-articular injections of colchicine on the normal joint of the rat was investigated. Colchicine in varying doses was injected into the knee, while the contralateral knee was used as a control. Colchicine mainly affected articular cartilage, causing degenerative changes that appeared to be dose-dependent. It is assumed that colchicine produces an increase in the rate of synthesis of collagenase, which alters the nature of articular cartilage, making it more susceptible to wear and tear and thus producing the lesions of early osteoarthritis.

Animals↗
PubMed1984

Colchicine in acute inflammation: stimulation of production of interleukin-1 and modulation of the acute phase serum amyloid A protein response.

The effects of colchicine on the acute phase serum amyloid A (SAA) response were studied in CBA/J mice to determine whether these effects are mediated via inhibition of interleukin-1 (IL-1) production. Prolonged pretreatment (72 h) with colchicine blunted the SAA response to stimulation with silver nitrate (AgNO3), while brief pretreatment (12 h) unexpected augmented SAA production. In a macrophage model, colchicine stimulated baseline production of IL-1 (SAA inducer and lymphocyte activating factor activities) and augmented lipopolysaccharide (LPS) induced IL-1 production. This indicates that colchicine does not inhibit amyloidosis via direct effects on early inducers of the acute phase SAA response.

Amyloid↗
PubMed1984

[Effect of colchicine and indomethacin on leukocytic phagocytosis of Staphylococcus aureus and E. coli].

The phagocytosis of S. aureus SG 511 and E. coli O4/K31 by human polymorphonuclear leucocytes is inhibited by colchicine in concentrations of 0.05 and 0.04%. In comparison to the controls the growth of bacteria was reduced but not stopped. If human blood is added to the culture medium, staphylococci multiply in the presence of all colchicine concentrations tested. In contrast E. coli grows only at a concentration of colchicine of 0.02-0.03%. Indomethacin dissolved in ethanol inhibited clearly the phagocytosis of S. aureus and E. coli. This inhibition was significant for concentrations of 2 X 10(-4) and 1 X 10(-4) mol/l. The behavior of the tested bacteria with respect to growth and multiplications was not affected. Indomethacin, however, retarded the bacterial growth in concentrations from 2 X 10(-4) up to 3.75 X 10(-5) mol/l. The multiplication of E. coli was stopped by indomethacin at a concentration of 2 X 10(-4) mol/l. If human blood is added to the phagocytosis test system with S. aureus and indomethacin, the bacteria will show a little reduction in the rate of the multiplication in concentrations of the compound from 2 X 10(-4) up to 3.75 X 10(-5) mol/l. At a concentration of 2 X 10(-4) mol/l, the growth of E. coli was inhibited. It is concluded that for the inhibition of phagocytosis--f. e. in blood culture systems--the concentration of colchicine must be 0.03-0.02%; for indomethacin an optimal concentration of 1 X 10(-4) mol/l is recommended.

Cell Division↗