7-nitrobenz-2-oxa-1-3-diazole-phallacidin and phallacidin

alpha-Thrombin interacts with confluent bovine pulmonary artery endothelial cells to produce two types of actin microfilament rearrangements: (1) The loss of cortical actin correlates with interruption of barrier integrity, evident from increased permeability to 125I-albumin; and (2) an increase in actin stress fibers results in greater adherence of the cells to their extracellular substrate. Use of phallatoxin compounds that stabilize actin filaments and prevent their depolymerization prevents both the cytoarchitectural and functional changes resulting from thrombin challenge.

Topics: Actins; Amanitins; Animals; Cattle; Cell Adhesion; Cell Division; Cell Survival; Cells, Cultured; Endothelium, Vascular; Fluorescent Dyes; Microscopy, Fluorescence; Peptides, Cyclic; Thrombin

The effect of an antidiuretic hormone (ADH, vasopressin) on the microfilament system of the toad urinary bladder lumenal epithelium was investigated using NBD-phallacidin (NBD-ph). The latter material is a specific fluorescent label for F actin. In the presence of an osmotic gradient, both ADH and cyclic adenosine monophosphate (cAMP) appear to induce the polymerization of monomeric actin into F actin-containing microfilaments. The latter may then be involved in the morphological changes, including the formation of lateral intercellular lakes, associated with the typical hydroosmotic response.

Topics: Actins; Amanitins; Animals; Arginine Vasopressin; Bufo marinus; Cyclic AMP; Cytoskeleton; Epithelium; Female; Microscopy, Fluorescence; Peptides, Cyclic; Thionucleotides; Urinary Bladder

Topics: Actins; Amanitins; Animals; Chromatography; Fluorescent Dyes; Macropodidae; Peptides, Cyclic; Spectrometry, Fluorescence