In the present study, we examined the effect of interleukin-2 (IL-2) on cardiomyocyte Ca(2+) handling. The effects of steady-state and transient changes in stimulation frequency on the intracellular Ca(2+) transient were investigated in isolated ventricular myocytes by spectrofluorometry. In the steady state (0.2 Hz) IL-2 (200 U/ml) decreased the amplitude of Ca(2+) transients induced by electr...

Rates of formation and dissociation of an abortive ternary complex between lactate dehydrogenase isozymes from various mammalian tissues, NADf, and pyruvate were studied utilizing stopped-flow spectrofluorometry. Formation of the complex was accompanied by a decrease in protein fluorescence at 340 rnp and a loss of lactate dehydrogenase activity. Rates of formation of an abortive lactate dehydr...

BACKGROUND Ischemia and adrenergic stimulation of cardiomyocyte cultures have been shown to induce apoptotic cell death. We hypothesized that in a model of contractile dysfunction following ischemia, a commonly used catecholamine such as dopamine augments cardiomyocyte apoptosis via activation of calcium-dependent signaling cascades. METHODS AND RESULTS Isolated perfused rabbit hearts were su...

PURPOSE Fluorescent bisretinoid compounds accumulate in retinal pigment epithelial (RPE) cells as a consequence of two processes: random reactions of vitamin A aldehyde in photoreceptor cell outer segments, and phagocytosis of discarded photoreceptor outer segment discs by RPE. The formation of bisretinoid is accentuated in some forms of retinal degeneration. The detection of a novel bisretinoi...

The aim of this study was to assess the level of malondialdehyde (MDA) in the seminal plasma of infertile men and to highlight a relationship between the level of MDA and semen parameters. Eighty-one infertile patients were divided into groups according to their clinical diagnosis: genitourinary infections, varicocele and idiopathic infertility. Semen quality was assessed by light and transmiss...

PURPOSE To investigate the in vitro, ex vivo, and in vivo transscleral-retinal pigment epithelium (RPE) permeability of PEDF and structurally related proteins for the exploration of novel routes of protein delivery to the retina. METHODS Monkey RPE cells were cultured on permeable supports to separate apical and basal compartments. Porcine scleral tissue was placed in Ussing chambers to separ...

Mesangial cell transformation into a proliferative phenotype, observed in many glomerular diseases, occurs in response to growth factors and cytokines. This study tests the hypothesis that intracellular calcium is necessary for stimulation of mesangial cell proliferative responsiveness to a variety of growth factors. Furthermore, these experiments tested whether nonspecific calcium entry via a ...

The green fluorescent protein (GFP) gene, gfp, of the jellyfish Aequorea victoria is being used as a reporter system for gene expression and as a marker for tracking prokaryotes and eukaryotes. Cells that have been genetically altered with the gfp gene produce a protein that fluoresces when it is excited by UV light. This unique phenotype allows gfp-tagged cells to be specifically monitored by ...

Ezrin is a member of ezrin, radixin, moesin (ERM) protein family that links F-actin to membranes. The NH(2)- and COOH-terminal association domains of ERM proteins, known respectively as N-ERMAD and C-ERMAD, participate in interactions with membrane proteins and F-actin, and intramolecular and intermolecular interactions within and among ERM proteins. In gastric parietal cells, ezrin is heavily ...

OBJECTIVE Protein kinase C (PKC) activation impairs contractility in the normal heart but is protective during myocardial ischemia. We hypothesized that PKC remains activated post-ischemia and modulates myocardial excitation-contraction coupling during early reperfusion. METHODS Langendorff-perfused rabbit hearts where subjected to 25 min unmodified ischemia and 30 min reperfusion. Total PKC ...