Human leukemia CEM C-1 cells possess a high affinity binding site for farnesol.

Binding of 15-carbon isoprenoid farnesol in human acute leukemia CEM C-1 cells has been studied by addition of radio-labeled isoprenoid to cell growth medium. Significant time-dependent accumulation of the cell-associated radioactivity was detected at 37 degrees C. When experiments were carried out at 4 degrees C, about 10 times decrease in cell labeling was observed.

[Ca2+ metabolism in the sarcoplasmic reticulum of skeletal muscle after surgical denervation].

The ability of sarcoplasmic reticulum to regulate Ca(2+)-metabolism was studied at different terms after surgical denervation. The increase of Ca(2+)-ATP-ase activity, intensification of active Ca(2+)-accumulation under insignificant change of passive Ca(2+)-outflow from sarcoplasmic reticulum vesicles were observed 3-days after denervation. At more remote terms 14 days and 28 days after denervation all these parameters decreased except for Km: Ca(2+)-ATP activity and active Ca2+ accumulation decreased below normal level.

[Effect of fluoroaluminate on the passive transport of calcium in the plasma membrane fraction of the pig myometrium].

Study of the effect of aluminium, fluoride-ions and fluoroaluminium on the passive transport of Ca2+ through the plasma membrane of the myometrium cells has shown that 10 microM of Al3+, 1 mM of F- and the both ions taken in the mentioned concentrations do not affect this process. At the same time 10 mM of F- as well as 10 microM of Al3+ together with 10 mM of F- inhibit a passive output of calcium from vesicles. The results obtained suppose that inhibitory regulation of the passive transport of calcium in the myometrium sarcolemma is executed through Gi-protein.

[Inhibiting effect of ADP-ribosylation by pertussis toxin on passive transport of Ca2+ into the cell membrane of porcine myometrium].

ADP-ribosylation by whooping cough toxin of protein components of inside-out oriented vesicles of pig myometrium plasma membranes under conditions of their depolarization results in significant inhibition of passive transport of Ca2+ ions. The inhibiting effect is dose- and time-dependent. rho-Chloromercuribenzoate (0.

[The effect of antibodies against Ca2(+)-ATPase and its hydrophobic fragment on the activity of this enzyme and on the passive transport of Ca2(+)].

It is shown that both Ca(2+)-ATPase and its hydrophobic fragment are immunogenic factors. A region between hydrophobic and hydrophilic parts of Ca(2+)-ATP-ase is immunogenic. These antibodies clearly inhibit inflow and outflow of Ca2+ through a hydrophobic fragment reconstructed into liposomes and do not influence Ca(2+)-ATPase activity.