Endothelial intracellular calcium ([Ca(2+)](i)) plays an important role in the function of the juxtaglomerular vasculature. The present studies aimed to identify the existence and molecular elements of an endothelial calcium wave in cultured glomerular endothelial cells (GENC). GENCs on glass coverslips were loaded with Fluo-4/Fura red, and ratiometric [Ca(2+)](i) imaging was performed using fl...

The regeneration of a new oral apparatus in Stentor coeruleus (oral regeneration) has been shown to be sensitive to events that inhibit calcium uptake and calmodulin function. Removal of extracellular calcium delays oral regeneration significantly. The calcium channel antagonist verapamil also delays oral regeneration, as does lanthanum, which is known to block calcium uptake. Both inhibitors a...

The role of extracellular calcium in the activation of respiratory burst in human neutrophils was studied by using the receptor agonist, N-formyl-methionyl-leucyl-phenylalanine (fMLP), and the activator of protein kinase C phorbol myristate acetate (PMA). The level of intracellular free calcium was measured by using both cell suspensions and single cells in the presence and absence of extracell...

Thy-1, an abundant mammalian glycoprotein, interacts with αvβ3 integrin and syndecan-4 in astrocytes and thus triggers signaling events that involve RhoA and its effector p160ROCK, thereby increasing astrocyte adhesion to the extracellular matrix. The signaling cascade includes calcium-dependent activation of protein kinase Cα upstream of Rho; however, what causes the intracellular calcium tran...

Products of ras genes are putative elements of growth factor signal transduction. However, the mechanism of action of these proteins in normal and malignant growth is as yet obscure. To test for functional consequences of ras oncogene expression, electrophysiological experiments were performed on NIH-3T3 fibroblasts transfected with a transforming Ha-ras MMTV-LTR construct expressing the oncoge...

Environmental estrogen mimics, including metalloestrogens that can activate estrogen receptor-alpha (ERa), may contribute to breast cancer risk. However, the underlying mechanisms through which these molecular mimics activate the ERa are generally poorly understood. With concern to this important question, we investigated whether intracellular calcium may mediate the cross-talk between signalin...