Refinement of a perfusion technique permitted the simultaneous measurement of cAMP-elicited [3H]cAMP secretion and intracellular [3H]cAMP levels in sensitive D. discoideum amoebae. These data were compared with measurements of the rate of [32P]cAMP synthesis by extracts of amoebae sonicated at different times during the cAMP signaling response. cAMP stimulation of intact cells led to a transien...

Anterior pituitary endocrine cells that release hormones such as growth hormone and prolactin are excitable fire action potentials. In these cells, several studies previously showed extracellular sodium (Na+) removal resulted in a negative shift of the resting membrane potential (RMP) subsequent inhibition spontaneous firing potentials, suggesting contribution Na+ background conductance. Here, ...

The presence of sialic acid on cell membranes was found to be necessary for the outward flow of proteins from L1210 leu kemia cells. The removal of membrane-bound sialic acid inhib ited the release of proteins without any effect on cell lysis, or on the release of nucleotides or sugars. The requirement for sialic acid in promoting protein secretion seemed relatively specific for certain protein...

BACKGROUND/AIMS Hyperphosphatemia is recognized as contributing to the increased risk of cardiac death in end-stage renal disease (ESRD) and hemodialysis (HD) patients. Currently available pharmacologic treatment for hyperphosphatemia is based on phosphate binders but, despite treatment, only half of the patients fall within the range for serum phosphorus of the K/DOQI guidelines. Therefore, th...

CD56+ cells have been recognized as being involved in bridging the innate and acquired immune systems. Herein, we assessed the effect of two major classes of immunostimulatory oligonucleotides (ODNs), PyNTTTTGT and CpG, on CD56+ cells. Incubation of human peripheral blood mononuclear cells (hPBMC) with some of these ODNs led to secretion of significant amounts of interferon gamma (IFN-γ), tumor...

OBJECTIVE Pharmacological LXR activation has anti-atherosclerotic actions in animal models. Part of these beneficial effects may be explained by accelerated reverse cholesterol transport since both plasma high density lipoprotein (HDL) cholesterol and fecal neutral sterol secretion are higher upon LXR activation. Mechanisms underlying these LXR-mediated effects have not been fully elucidated. ...

CD36 mediates the transfer of fatty acids (FAs) across the plasma membranes of muscle and adipose cells, thus playing an important role in regulating peripheral FA metabolism in vivo. In the proximal intestine, CD36 is localized in abundant quantities on the apical surface of epithelial cells, a pattern similar to that of other proteins implicated in the uptake of dietary FAs. To define the rol...