Adrenocorticotropin (ACTH)-stimulated cholesterol transport to mitochondria has been quantitated in rat adrenals in vivo and in adrenal cell suspensions. The initial rate of transport (1.25 pg/mg of mitochondria/ min) is similar in vivo and in cell suspensions, but the mitochondrial cholesterol level reaches higher levels in uivo. ACTH stimulation of cholesterol transport into mitochondria when...

The maturation of two enveloped viruses, influenza and vesicular stomatitis, occurs in cells treated with cytochalasin B. Virions produced in the presence of 50 microgram/ml cytochalasin B (CB) appear to be as infectious as those from control cells, indicating that polymerized actin is not required for the assembly of functional viral components. CB inhibits the release of influenza virus from ...

INTRODUCTION aspects of microvillar morphogenesis . This report describes the cytological events that result from exposure of embryonic intestine to CB in organ culture . The ultrastructure of microvilli comprising the brush border of cells of the intestinal epithelium has been extensively studied (e .g ., Ito, 1965 ; Overton et al ., 1965 ; Brunser and Luft, 1970; Mukherjee and Staehelin, 1971...

The effect of cytochalasin B (CB) on beating, electrical activity and cytological ultrastructure of embryonic hearts and tissue-cultured heart preparations was investigated. The inhibition of spontaneous pulsation and the subsequent recovery after drug washout were found to be dosedependent and to be a function of the type of preparation. In the presence of CB, spontaneous action potentials can...

When the 100,000 g supernatant fraction (extract) of HeLa cells lysed in a buffer containing sucrose, ATP, DTE, EGTA, imidazole, and Triton X-100 is incubated at 25 degrees C, it gels, and actin and a HMWP are progressively enriched in the extract and in gel isolated from extract. CB (greater than or equal to 0.25 muM) inhibits gelation and specifically lowers the concentrations of actin and th...

Total outflow facility was determined in both eyes of cynomolgus monkeys by two-level constant pressure perfusion. After a baseline measurement, one eye of the experimental animal received intracameral cytochalasin B (CB); the other eye received vehicle without CB. Twenty minutes later both eyes received intracameral epinephrine (EPI), and 30 min later the outflow facility was again determined....

Detailed studies of [3mcytochalasin B-binding and the inhibition of glucose transport by cytochalasin B have recently permitted characterization of a specific class of D-glucose-inhibitable cytochalasin B-binding sites in purified isolated rat adipose cell plasma membranes, identification of these sites as functional glucose transport systems, and direct demonstration that insulin stimulates gl...

Several factors can influence the development of axons and dendrites in vitro. Some of these factors modify the adhesion of neurons to their substratum. We have previously shown that the threshold of neuron-substratum adhesion necessary for initiation and elongation of dendrites is higher than that required for axonal growth. To explain this difference we propose that, in order to antagonize ac...

The integrity of F-actin and its association with the activation of a Cl- current ( I Cl) in cultured chick cardiac myocytes subjected to hyposmotic challenge were monitored by whole cell patch clamp and fluorescence confocal microscopy. Disruption of F-actin by 25 μM cytochalasin B augmented hyposmotic cell swelling by 51% (from a relative volume of 1.54 ± 0.10 in control to 2.33 ± 0.21), wher...

Chemoattractants stimulate actin polymerization in lamellipodia of polymorphonuclear leukocytes. We find that removal of chemoattractant results in rapid (within 10 s at 37 degrees C) and selective depolymerization of the F-actin located in lamellipodia. Addition of 10 microM cytochalasin B, in the presence of chemoattractant, also resulted in rapid and selective depolymerization of lamellar F-...