The adhesion of normal mouse macrophages to glass surfaces was reduced by nontoxic levels (1-50 mug/ml) of cytochalasin B in combination with a centrifugal force (1,000-8,000 g). Macrophages nonspecifically activated by Corynebacterium acnes were also detached by this treatment, but less effectively. The effects of cytochalasin B treatment on these cells were shown to be reversible. After detac...

The active role played by beta-cell microfilamentous structures in the dynamics of insulin secretion was investigated by examining the influence of cytochalasin B upon various parameters of hormonal release by the isolated perfused rat pancreas. The view that the cytochalasin-induced changes in insulin release are due to a primary biophysical effect on microfilaments, rather than to an unrelate...

To test the idea that cytochalasin retards actin assembly by binding to filament ends, we have designed a new assay for cytochalasin binding in which the number of filament ends can be varied independently of the total actin concentration. Actin is reacted with polylysine-coated polystyrene beads to make filament ends (Brown and Spudich, 1979, J. Cell Biol. 80:499-504) and then reacted with [3H...

1. Cytochalasin B (10mug/ml) enhances the release of rabbit polymorphonuclear leucocyte lysosomal acid hydrolases induced by retinol (vitamin A alcohol). 2. This effect is seen at doses of the vitamin that cause selective release of acid hydrolases and those causing more general enzyme release indicated by the loss of lactate dehydrogenase. 3. Cytochalasin B (2-50mug/ml) has no effect on the re...

We have recently reported (3) that cytochalasin B, which disrupts microfilaments, and colchicine, which disrupts microtubules, interfered with the release of a-amylase from rat parotid tissue slices . Our observations on the effect of cytochalasin B on a-amylase release have been confirmed by Rifkin et al . (14) . Inhibitory actions of cytochalasin B or colchicine in several other systems have ...

The role of cytoskeletal microtubules and microfilaments in modulating cAMP generation in S49 lymphoma cells was investigated using the agents colchicine and cytochalasin B, respectively, which are known to disrupt these structures. A 1-hr pretreatment of S49 cells with 10 microM colchicine typically enhanced maximal isoproterenol-(beta-adrenergic receptor) stimulated cAMP accumulation by 100%,...

INTRODUCTION the addition of the drug . Concentrations of about 3 μg/ml were required to observe altered cell morphology. The possibility was considered that depolymerization of microfilaments-with a resulting change in cell shape and function--resulted from a rapid depletion of intracellular energy levels brought about by the inhibition of sugar transport . The effects of cytochalasin B and io...