It is now accepted that many hormones and neurotransmitters exert their effects through G protein-mediated activation of a phospholipase C, which breaks down phosphatidylinositol bisphosphate. This releases inositol trisphosphate, which mobilizes intracellular calcium, and diacylglycerol, which, in turn, activates protein kinase C. However, recent evidence indicates that other mechanisms are in...

The paper discusses a possible new concept of the role of fluoride and its mechanism of action in caries prevention. In the past fluoride inhibition of caries was ascribed to reduced solubility due to incorporation of fluoride (F) into the enamel minerals (firmly bound fluoride or fluorapatite). Based on the new findings, it appears that fluoride, either released into or present in the fluid ph...

Cardiomyocyte excitation–contraction coupling is tightly regulated through coordinated calcium release and uptake that is facilitated by two proteins in the sarco/endoplasmic reticulum (SR/ER) membrane, the ryanodine receptor (Ryr), and the sarco/endoplasmic reticulum Ca2+-ATPase (SERCA), respectively. Dysregulated calcium handling is a hallmark in cardiac dysfunction (1–3). Our understanding o...

Since calcium solubility is a prerequisite to calcium absorption, and since solubility of calcium is highly pH-dependent, it has been generally assumed that gastric acid secretion and gastric acidity play an important role in the intestinal absorption of calcium from ingested food or calcium salts such as CaCO3. To evaluate this hypothesis, we developed a method wherein net gastrointestinal abs...

Objective: An experiment was conducted to investigate the effects of citrus brown snail powder as a source of calcium on growth performance, tibia characteristics, immune response and blood metabolites in broiler chickens.  Methods: One hundred and eighty 1-day old chicks were randomly distributed into four treatments, each of which had three replicates. Each replicate contains 15 chicks. The t...

Hydroxyapatite bio-ceramic powder was synthesized using waste eggshells as calcium source by a straight forward thermal method. The process is carried out at high temperature. Different calcium phosphate phases were obtained just by changing the thermal treatment. HAp is the only apatite present in the reaction products, along with minute fractions of other calcium compounds. The final product ...

A number of mesenchymal cells (fibroblasts, macrophages and megakaryocytes) respond to a variety of stimuli with large hyperpolarizations lasting several seconds (the H.A. response). The H.A. responses can occur as repetitive trains or oscillations. These hyperpolarizations are due to an increase of the surface membrane permeability to potassium ions which is probably mediated by an increase in...