In nonexcitable cells, the predominant mechanism for regulated entry of Ca(2+) is capacitative calcium entry, whereby depletion of intracellular Ca(2+) stores signals the activation of plasma membrane calcium channels. A number of other regulated Ca(2+) entry pathways occur in specific cell types, however, and it is not know to what degree the different pathways interact when present in the sam...

Many studies have clarified that poly(γ-glutamic acid) (PGA) increases the solubility of Ca 2+ , suggesting that PGA enhances calcium absorption in the small intestine. However, there has been no report on the specific interaction between PGA and Ca 2+ in water. We studied the aqueous solution properties of PGA calcium salt (PGA-Ca complex). The chelating ability and binding strength of PGA for...

Background: Given that the world's population is aging, the problems associated with osteoporosis and related fractures are increasing. The aim of the study was to evaluate the effect of flaxseed extract on bone mineral density (BMD) in Wistar rats using digital radiography. Methods: In this experimental study, 25 male and 25 female Wistar rats were randomly divided into 5 groups: 1. Control...

BACKGROUND Few interventions directly compare equivalent calcium and vitamin D from dairy vs. supplements on the same bone outcomes. The radioisotope calcium-41 ((41)Ca) holds promise as a tracer method to directly measure changes in bone resorption with differing dietary interventions. OBJECTIVE Using (41)Ca tracer methodology, determine if 4 servings/day of dairy foods results in greater (4...

Calcium efflux has been studied in squid giant axons under conditions in which the internal composition was controlled by means of a dialysis perfusion technique. The mean calcium efflux from axons dialyzed with 0.3 microM calcium and 5 mM ATP was 0.26 pmol/cm(2).s at 22 degrees C. The curve relating the Ca efflux with the internal Ca concentration had a slope of about one for [Ca](i) lower tha...

BACKGROUND Chronic renal failure has been referred to as a state of cellular calcium toxicity. The aim of this study was to investigate the status of free cytosolic calcium ([Ca(2+)](i)), intracellular calcium reserves and the capacitative calcium entry in peripheral blood mononuclear cells (PBMCs) of early-stage chronic kidney disease (CKD) patients, and to determine the effect of vitamin D(3)...

Caveolae are plasma membrane invaginations enriched in sterols and sphingolipids. Sphingosine kinase 1 (SK1) is an oncogenic protein that converts sphingosine to sphingosine 1-phosphate (S1P), which is a messenger molecule involved in calcium signaling. Caveolae contain calcium responsive proteins, but the effects of SK1 or S1P on caveolar calcium signaling have not been investigated. We genera...

Yi-Chung Hsieh, Ying-Ru Chen, Err-Lieh Hsu and Rong Kou (2003) Pharmacological effects of calcium channel agtagoinsts on juvenile hormone acid release and intracellular calcium level in the corpora allata of adult male Mythimna loreyi (Lepidoptera: Noctuidae). Zoological Studies 42(2): 336-345. The pharmacological effects of calcium channel antagonists on the in vitro release of juvenile hormon...

Calcium aluminates (CA) are the most important hydraulically setting cements used for preparing refractory castables, because they develop high strength at very early ages after placements.  The anhydrous phases of this kind of cements are CA, CA2 and traces of C12A7 and alpha-alumina. The major hydraulic phase in all of the CA cements including ciment fondu...