[A morphofunctional analysis of the changes in the Golgi apparatus in the epitheliocytes of the frog bladder under conditions of the vasopressin stimulation of water transport].

Structural and chemical peculiarities of the Golgi apparatus elements in granular cells of the normal frog urinary epithelium and under vasopressin stimulation of water transport have been studied with different electron microscopic methods: standard chemical fixation, prolonged osmification, freeze-substitution, freeze-fracture, immunocytochemistry, and electron-probe X-ray microanalysis. The structure of the main Golgi elements and its derivatives in normal cells and under the stimulation of water transport has been described. The association of microtubules with the Golgi cisternae was shown. Microtubules are supposed to participate in the support of integrity of the Golgi complex (in normal cells). Under stimulated water transport, depolymerization of microtubules seems to occur, resulting eventually in the Golgi fragmentation. Participation of some specific granules, that are the Golgi derivatives, in the increase of apical membrane water permeability has been shown as the insertion of water channels. Besides, under big water flows, the Golgi cis-cisternae were shown to participate in the formation of large vacuoles containing low potassium. A supposition is put forward that these vacuoles may perform an osmoregulative function in the cell, similar to that of contractile vacuoles of Protozoa.