The ATPase activities of Acanthamoeba and muscle actins in 0.5-0.6 mM MgClz were examined below and above their critical concentrations and in the presence and absence of cytochalasins B, C, D, and E. In the absence of cytochalasin, the ATPase activity of actin solutions at steady state increased with increasing actin concentration through the critical concentration and continued to increase as...

Three antipeptide antibodies were prepared by immunizing rabbits with synthesized short peptides corresponding to residues 215-226, 466-479, and 478-492 predicted from the cDNA of both the human hepatoma HepG2 and rat brain glucose transporters. All three antibodies were found to precipitate quantitatively the [3H]cytochalasin B photoaffinity-labeled human erythrocyte glucose transporter. Each ...

The hardening of the zona pellucida as a result of the cortical reaction was estimated in triploid oocytes produced with cytochalasin B by two different procedures. Triploid oocytes resulting from fertilization in the presence of cytochalasin B did not reveal hardening of the zona pellucida unlike triploids obtained by inhibiting in-vitro extrusion of the second polar body in oocytes fertilized...

To examine the relationship between binding of surface-active stimuli to human neutrophils and activation of the superoxide (02. ) and peroxide (H202) forming oxidase(s) of these cells. oxygen (02) consumption and 02. and H202 release were measured following stimulation by plant lectins. Both concanavalin A (Con-A) and phytohemagglutinin (PHA) were more active than other lectins in stimulating ...

In the presence of very low concentrations (about 2X10(-7) M) of cytochalasin B (CB) the time course of actin polymerization is much more sigmoidal when followed by viscosity measurements than when followed by light scattering measurements. This suggests that under these conditions actin polymers do not immediately reach their final length but only via short "bent" polymers which can be detecte...

To compare the effects of cytochalasins on the cellular level with those on the molecular level, 24 cytochalasins, 20 natural compounds and 4 derivatives, were used. The following effects were tested for each of 24 cytochalasins; (a) four high dose (2-20 muM) effects on the cellular level: rounding up of fibroblastic cells, contraction of actin cables, formation of hairy filaments containing ac...

A variety of agents, e .g. colchicine, that are known to affect mitosis are also of value in providing information about motility of and within the cell . Cytochalasins isolated from yeast by W . B . Turner, and shown by Carter and others to inhibit motility and to block cell division, may be classified as another antimotility group (1) . One unique feature of this compound is that it may be sp...

Cytochalasin B (37 fig per ml) reduces the rate of food vacuole formation, i.e. the rate of phagocytosis, in Tetrahymena pyriformis. Cytochalasin B in this concentration suppresses multiplication rates in a nutrient medium consisting of 2 % proteose peptone, but multiplication is unaffected if this medium is supplemented with glucose and high concentrations of nucleosides. Thus nutrients in hig...

OBJECTIVE To investigate whether cytochalasin D-eluting stents (CDES) suppress intimal hyperplasia in porcine coronary arteries and to compare the efficacy of paclitaxel and cytochalasin D as inhibitors of vascular smooth muscle cell (SMC) proliferation and platelet aggregation in vitro. METHODS Rabbit platelet-rich plasma and SMC cultures derived from rabbit aortas were exposed to 10(-8)-10(...