Calcium (Ca²⁺) is an important cation able to function as a second messenger in different cells of the immune system, particularly in B and T lymphocytes, macrophages and mastocytes, among others. Recent discoveries related to the entry of Ca²⁺ through the store-operated calcium entry (SOCE) has opened a new investigation area about the cell destiny regulated by Ca²⁺ especially in B and T lymph...

Calcium influx drives two opposing voltage-activated calcium channel (Ca(V)) self-modulatory processes: calcium-dependent inactivation (CDI) and calcium-dependent facilitation (CDF). Specific Ca(2+)/calmodulin (Ca(2+)/CaM) lobes produce CDI and CDF through interactions with the Ca(V)alpha(1) subunit IQ domain. Curiously, Ca(2+)/CaM lobe modulation polarity appears inverted between Ca(V)1s and C...

Axonal populations in neonatal and mature optic nerves were selectively stained with calcium dyes for analysis of calcium homeostasis and its possible coupling to axonal Na. Repetitive nerve stimulation causes a rise in axonal [Ca(2+)](i) the posttetanus recovery of which is impeded by increasing the number of action potentials in the tetanus. This effect is augmented in 4-aminopyridine (4-AP; ...

Four hundred and eighty mixed-sex broiler chicks aged 3 hrs after hatching were allotted according to a completely random design in a 6 × 2 × 2 factorial schedule into 2 groups of 12 replications of 20 chicks each. The main experimental factors were fasting for 0, 6, 12, 24, 36, and 48 hrs after chick placement, calcium gluconate (Ca-glu) injection (0 and 0.6 mL) and sex (male and female). Inde...

Calcium ion (Ca 2+ ) is the most important universal signal carrier used by living organisms, including plants, to convey information to many different cellular processes. The cytosolic free Ca 2+ concentration ([Ca 2+ ] cyt ) has been found to increase in response to many physiological stimuli, including stress. The Ca 2+ spikes normally result from two opposing reactions, Ca 2+ influx through...

Tully, Keith and Steven N. Treistman. Distinct intracellular calcium profiles following influx through Nversus L-type calcium channels: role of Ca -induced Ca release. J Neurophysiol 92: 135–143, 2004; 10.1152/jn.01004.2003. Selective activation of neuronal functions by Ca is determined by the kinetic profile of the intracellular calcium ([Ca ]i) signal in addition to its amplitude. Concurrent ...

Calcium doped nickel ferrite powders have been prepared by sol-gel combustion technique. Metal nitrates, such as calcium nitrate, nickel nitrate and ferric nitrate, were used as the source materials and citric acid and polyvinyl alcohol were used as the burning agent and agglomeration reducing agent, respectively. The average crystallite size of the prepared ferrite was in the order of ~70- 92 ...

Calcium doped nickel ferrite powders have been prepared by sol-gel combustion technique. Metal nitrates, such as calcium nitrate, nickel nitrate and ferric nitrate, were used as the source materials and citric acid and polyvinyl alcohol were used as the burning agent and agglomeration reducing agent, respectively. The average crystallite size of the prepared ferrite was in the order of ~70- 92 ...

1. The net flux of 45Ca from lumen to blood side across the isolated and short-circuited Cecropia midgut was 1-9 +/- 0-2 muequiv. cm-2h-1 in 8 mM Ca and the flux ratio was as high as 56 to 1. 2. The calcium influx was depressed by anoxia; 73% after 30 min. 3. The kinetics of Ca transport were anomalous; the apparent Km varied with Ca concentration from less than 0-2 to greater than 5-6 mM Ca an...

In most non-excitable cells, calcium (Ca(2+)) release from the inositol 1,4,5-trisphosphate (InsP(3))-sensitive intracellular Ca(2+) stores is coupled to Ca(2+) influx through the plasma membrane Ca(2+) channels whose molecular composition is poorly understood. Several members of mammalian TRP-related protein family have been implicated to both receptor- and store-operated Ca(2+) influx. Here w...