Cell Motil Cytoskeleton. 2002 Nov;53(3):189-202.
Localised depletion of polymerised actin at the front of Walker carcinosarcoma cells increases the speed of locomotion.

Keller H, Zadeh AD, Eggli P.

Institute of Pathology, University of Bern, Bern, Switzerland. kellerhatho.unibe.ch

Spontaneously migrating Walker carcinosarcoma cells usually form lamellipodia at the front. Combined treatment with 10(-5)M colchicine and 10(-7)M latrunculin A produces large defects in the cortical F-actin layer at the leading front and suppresses lamellipodia. However, the cortical actin layer at the rear is intact and shows myosin IIA accumulation. These cells, showing no or little detectable cortical F-actin at the front and no morphologically recognisable protrusions, migrate faster than control cells with lamellipodia and an intact cortical actin layer. This documents that the cortical actin layer or actin-powered force generation at the front is redundant for locomotion. Colchicine and latrunculin A have synergistic effects in compromising the cortical layer at the front and in increasing the speed of locomotion, but antagonistic effects on the relative amount of F-actin per cell. Colchicine but not latrunculin A, can increase the proportion of polarised and locomoting cells under appropriate conditions. Locomotion and polarity of cells treated with latrunculin A and colchicine is inhibited at latrunculin A concentrations >10(-7)M, by the myosin inhibitor BDM or the ROCK inhibitor Y-27632. Colchicine and Y-27632 have antagonistic effects on polarity and the speed of locomoting cells. The data show that locomotion of metazoan cells, which normally form lamellipodia, can be driven by actomyosin contraction behind the front (cell body, uropod). They are best compatible with a cortical contraction/frontal expansion model, but they are not compatible with models implying that actin polymerisation or actomyosin contraction at the front drive locomotion of the cells studied. 2002 Wiley-Liss, Inc.


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Toxicol Sci. 2002 Sep;69(1):175-82.
Microtubules of the mouse testis exhibit differential sensitivity to the microtubule disruptors Carbendazim and colchicine.

Correa LM, Nakai M, Strandgaard CS, Hess RA, Miller MG.

Department of Environmental Toxicology, University of California, One Shields Avenue, Davis, California 95616, USA. Imcorrecdavis.edu

The testicular toxicant benomyl and its metabolite, carbendazim cause reproductive damage to the rat, an early sign of which is sloughing of germ cells with associated Sertoli cell fragments. However, the sensitivity of other mammalian species to these benzimidazole compounds is not clear. In this study, the effects of carbendazim and colchicine, a known microtubule disruptor, on the mouse seminiferous epithelium were characterized, and the amount of carbendazim reaching the mouse testis was measured. Testes were assessed for histological effects 3 h and 6 h after administration of carbendazim (2000 mg/kg, ip), and 6 h after intratesticular administration of either a low or high dose (5.3 or 117.6 micro g/g testis) of colchicine. Carbendazim caused no signs of histological damage to the mouse testis, and the microtubule cytoskeleton was intact and identical to controls based on immunostaining with tyrosinated alpha tubulin and beta tubulin antibodies. Similarly, the seminiferous epithelium of mouse testis was undamaged and the microtubule cytoskeleton was intact after a low dose of colchicine, while a comparable dose of colchicine injected into rat testis caused marked toxicity. However, mouse testes did show microtubule disruption and severe germ cell sloughing after administration of a high dose of colchicine. The amount of carbendazim measured in mouse testis was 375 nmol/g testis, which is higher than the value measured in rat testis after a toxic dose of carbendazim. Therefore, carbendazim reaches the mouse testis at or above levels measured in the rat, yet the mouse is apparently insensitive to this microtubule disrupting agent.


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Nephron. 2002 Oct;92(2):422-30.
Colchicine suppresses osteopontin expression and inflammatory cell infiltration in chronic cyclosporine nephrotoxicity.

Li C, Yang CW, Ahn HJ, Kim WY, Park CW, Park JH, Cha JH, Kim J, Kim YS, Bang BK.

Department of Internal Medicine, KangNam St. Mary's Hospital, Catholic University of Korea, 505 BanPo-Dong, SeoCho-Ku, 137-040 Seoul, Korea.

BACKGROUND: Colchicine (Col) is beneficial to renal injury because of its anti-inflammatory effect, but its mechanism has yet to be elucidated. The present study was designed to evaluate the inhibitory effects of colchicine on osteopontin (OPN) expression and the macrophage accumulation in chronic cyclosporine (CsA) nephrotoxicity in rats. METHODS: Male adult Sprague-Dawley rats on a low salt diet (LSD, 0.05% sodium) were treated daily with Col (30 microg/kg), CsA (15 mg/kg), and both CsA and colchicine or vehicle (olive oil 1 ml/kg) for 4 weeks. The effects of colchicine on chronic CsA nephrotoxicity were evaluated by examining renal function, histopathology, and ED-1 positive cells. The expressions of OPN mRNA and protein were estimated respectively by Northern blot and immunohistochemistry. RESULTS: Compared with vehicle-treated rats, CsA-treated rats showed an increase in serum creatinine, a decline in creatinine clearance rate, and tubulointerstitial fibrosis (all p < 0.01). Concomitant administration of colchicine reversed all of the above parameters (all p < 0.01). Of note, the upregulated expression of osteopontin mRNA and protein seen in CsA-treated rats was significantly decreased after colchicine treatment. Furthermore, the expression of osteopontin mRNA was strongly correlated with the number of ED-1 positive cells (r = 0.712, p < 0.001) and the tubulointerstitial fibrosis score (r = 0.586, p = 0.007). CONCLUSION: Colchicine is capable of abrogating the upregulation of chemotactic OPN expression and macrophage influx, and this is associated with improved renal tubulointerstitial fibrosis in chronic CsA nephrotoxicity. 2002 S. Karger AG, Basel


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J Anal Toxicol. 2002 Sep;26(6):365-9.
Application of LC-MS analysis to a colchicine fatality.

Jones GR, Singer PP, Bannach B.

Office of the Chief Medical Examiner, Edmonton, Alberta, Canada.

A 73-year-old man developed nausea, vomiting, and diarrhea 20-30 min after receiving a 1.0 mg intravenous dose of colchicine for the treatment of severe pain due to gouty arthritis in his physician's office. He was hospitalized 8 h later, and his condition deteriorated as he developed renal and respiratory failure. He subsequently died 10 h later, or a total of 18 h after he received the original 1 mg colchicine injection. The patient received a prescription for oral 0.6 mg colchicine tablets 8 days previously and consumed eight tablets during that period, an average of 0.6 mg/day (42 of 50 tablets remained at the time of death). Colchicine concentrations were measured by liquid chromatography-mass spectrometry in selected ion monitoring mode using positive ionization. Chromatography was performed using an Eclipse XDB C8 analytical column (30 mm x 2.1-mm i.d., 3-microm particle size) and a programmed mobile phase consisting of 50 mM pH 4 ammonium acetate buffer and acetonitrile. Colchicine concentrations were as follows: 50 microg/L in cardiac blood, 10 microg/L in vitreous humor, 575 microg/kg in liver, 12,000 microg/L in bile, and 4.4 microg in 60 g received gastric contents (estimated total gastric contents 100 g). The cause of death was ruled to be "acute colchicine toxicity" and the manner of death "accidental."


Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12220019&dopt=Abstract colchicine