Cytobios. 1978;23(90):119-39.
Cell wall biogenesis in Oocystis: experimental alteration of microfibril assembly and orientation.

Montezinos D, Brown RM Jr.

Cell wall biogenesis in the unicellular green alga Oocystis apiculata has been studied. Under normal growth conditions, a cell wall with ordered microfibrils is synthesized. In each layer there are rows of parallel microfibrils. Layers are nearly perpendicular to each other. Terminal linear synthesizing complexes are located in the plasma membrane, and they are capable of bidirectional synthesis of cellulose microfibrils. Granule bands associated with the inner leaflet of the plasma membrane appear to control the orientation of newly synthesized microfibrils. Subcortical microtubules also are present during wall synthesis. Patterns of cell wall synthesis were studied after treatment with EDTA and EGTA as well as divalent cations (MgSO4, CaSO4, Cacl2). 0.1 M EDTA treatment for 15 min results in the disassociation of the terminal complexes from the ends of microfibrils. EDTA-treated cells followed by 15 min treatment with MgSO4 results in reaggregation of the linear complexes into a paired state, remote from the original ends to which they were associated. After 90 min treatment with MgSO4, normal synthesis resumes. EGTA and calcium salts do not affect the linear complexes or microfibril orientation. Treatments with colchicine and vinblastine sulphate do not depolymerize the microtubles, but the wall microfibril orientation is altered. With colchicine or vinblastine, the change in orientation from layer to layer is inhibited. The process is reversible upon removal of the drugs. Lumicolchicine has no effect upon microfibril orientation, but granule bands are disorganized. Treatment with coumarin, a known inhibitor of cellulose synthesis, causes the loss of visualization of subunits of the terminal complexes. The possibility of the existence of a membrane-associated colchicine-sensitive orientation protein for cellulose microfibrils is discussed. Transmembrane modulation of microfibril synthesis and orientation is presented.


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Tsitologiia. 2002;44(7):623-31.
[Induction of morphologically and genetically unstable calluses of Fagopyrum tataricum by colchicine]

[Article in Russian]

Mukhitov AR, Rumiantseva NI.

Kazan' Institute of Biochemistry and Biophysics, Kazan' Research Centre RAS.

A study was made of colchicine effect on genetic and morphological stability of morphogenic calli of the tatar buckwheat Fagopyrum tataricum (L.) Gaertn. A prolonged exposure of the morphogenic callus in colchicins-containing medium led to its morphological changes: the callus became more friable, and proembryogenic cell complexes disappeared. Genetic non-stability started from the first days of culturing in colchicine-containing indicated by amitotic divisions and K-mitoses, leading to the formation of micronuclei and increased variability in chromosome number. As a result of colchicine action, a few lines of heterogeneous calli were obtained differing in morphology, chromosome numbers, and ability to morphogenesis from the primary morphogenic callus. Genetic instability appeared in the following passages, when the treated calli were subcultured in the medium without colchicine: a wide range of abnormal nuclear division and chromosome aberrations was observed. This prolonged genetic instability was accompanied by a prominent increase in the formation of friable clones, which was 20-30 times higher than in the control. The formation of friable clones seems to result from one or two point mutations.


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J Bioenerg Biomembr. 1979 Dec;11(5-6):103-12.
Colchicine effect on the permeability of the whole epithelium and of isolated cells of frog skin.

Svelto M, Cremaschi D, Lippe C.

The effect of 2 X 10(-5) M colchicine on epithelial cells isolated from frog skins was investigated. Three hours of treatment with colchicine did not change either Na+ and K+ content of isolated cells or nonelectrolyte permeability. When ADH (50 mU/ml) was added, thiourea uptake values became greater than without the hormone; the same values were found in the cells previously treated with colchicine. Na+ transepithelial transport, measured by means of short-circuit current, was inhibited by the antimitotic agent both under control conditions and after ADH stimulation. These results support the view that colchicine does not directly affect ADH action on membrane permeability, but influences some mechanism that controls ADH action on transepithelial transport. Intercellular junctions appear to be the location of such a mechanism.


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J Pharmacol Exp Ther. 1975 Jul;194(1):154-8.
Mechanism of action of colchicine. I. Effect of colchicine and its analogs on the reversed passive Arthus reaction and the carrageenan-induced hindpaw edema in the rat.

Chang YH.

Colchicine and N-desacetyl-N-methylcolchicine suppressed both the reversed passive Arthus reaction and the carrageenan-induced edema in the rat. Colchicine, 2-desmethyl-colchicine glucoside and trimethylcolchicine acid had no effect on either model of inflammation. The ability or inability of these compounds to suppress the development of experimental inflammation correlated with their antimitotic activities. The findings lend support to the hypothesis that the anti-inflammatory and the antimitotic effects of colchicine may depend on the same basic, biophysical mechanism of action, i.e., the disruption of the microtubules.


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