Action des acides caproïque et caprylique sur les mitoses de segmentation chez Triturus helveticus Razoumowsky

Caproic (hexanoic) and caprylic (octanoic) acids 0,01 M (pH 5) are comparatively studied. After 3 hours they do not destroy spindle fibers, but produce several abnormalities classified and hierarchized as follows: 1) bipolar mitoses with inactive poles and blocked centrospheres, 2) mitoses with two dominant poles including centrospheres and secondary poles without them, 3) special pluripolar mitoses with an equatorially dissociated spindle and more or less efficient poles. Partial inhibition of polar activity results in extended hyperfibrillar diastema, which proliferates in fibrillar hollow spheres and burses, but is unable of inducing furrowing. Mechanisms of these disturbances are discussed. Asynchronism and acceleration of polar activity are determined by the absence of the first cleavage. Chromosomal alterations (thickening, deformations and clumping) are partially reversible, but result in chromosomes breakage and recombinations. Stronger activity and toxicity of caprylic acid may be related to its longer carbonic chain.