| Autor: |
Wade, J. B., Kachadorian, W. A. |
| Zdroj: |
American Journal of Physiology - Cell Physiology; October 1988, Vol. 255 Issue: 4 pC526-C530, 5p |
| Abstrakt: |
The possible role of actin microfilaments in antidiuretic hormone (ADH)-induced increases in apical membrane water permeability was investigated in studies that evaluate inhibition by cytochalasin B of both permeability and membrane structural responses in the toad urinary bladder. Experiments were carried out in the absence of a transepithelial osmotic gradient to eliminate possible flow-induced distortions of the response. Measurements of osmotic water permeability after a brief tissue fixation with glutaraldehyde show that cytochalasin B reduces the permeability response to ADH by approximately one-third. Freeze-fracture electron microscopy indicates that the intramembrane particle aggregates, previously found to correlate closely with ADH-induced permeability, are reduced by about the same extent (28%) under these conditions. However, the frequency of apical membrane fusion events was not affected by cytochalasin B treatment. These results suggest that cytochalasin B treatment in the absence of an osmotic gradient alters the ADH-induced permeability through an effect on apical membrane aggregate frequency. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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