Search

Cyclic adenosine diphosphoribose (cADPR), a recently discovered metabolite of nicotinamide adenine dinucleotide (NAD), is a potent calcium-releasing agent postulated to be a new second messenger. An enzyme that catalyzes the synthesis of cADPR from NAD and the hydrolysis of cADPR to ADP-ribose (ADPR) was purified to homogeneity from canine spleen microsomes. The net conversion of NAD to ADPR categorizes this enzyme as an NAD glycohydrolase. NAD glycohydrolases are ubiquitous membrane-bound enzymes that have been known for many years but whose function has not been identified. The results presented here suggest that these enzymes may function in the regulation of calcium homeostasis by the ability to synthesize and degrade cADPR., The concentration of cytosolic free [Ca.sup.2+] is a key factor in cellular regulation (1). Many extracellular signals stimulate the synthesis of the second messenger inositol 1,4,5-trisphosphate, which activates membrane [Ca.sup.2+] [...]

Ipriflavone, a synthetic phytoestrogen, enhances intestinal calcium transport in vitro. Arjmandi BH, Khalil DA, Hollis BW. Calcif Tissue Int 2000;67:225-229. Ipriflavone (IP), a synthetic isoflavone, prevents bone loss associated with [...]

Occult Drosophila Calcium Channels and Twinning of Calcium and Voltage-Activated Potassium Channels IN Drosophila DEVELOPMENT, THE LAST of three larval stages terminates with the formation of a puparium and the [...]

To understand the processes by which organisms from minerals, the first-formed mineral deposit must be identified and characterized. In some cases the mature mineral may well be identical to the [...]