OBJECTIVETo study the characteristics of dry matter accumulation and N, P, K, Ca and Mg accumulation and distribution of Chrysanthemum morifolium.

METHODThe sampling were carried out on the different growing time of C. morifolium, and the amount of dry matter and the content of N, P, K, Ca and Mg in all parts of the plant were measured.

RESULTThe dry matter accumulation was lineally increased with the absorption and accumulation of N, P, K, Ca, and Mg. In different growing periods, the accumulation and distribution of mineral nutrition were different in C. morifolium. The mineral nutrition was mostly in the leaf of the plant in the vegetative period. When the growth changed from vegetative growth to reproductive growth, the mineral nutrition was transferred and distributed into bud, flower and root shoot. And the period of flower bud differentiation of C. morifolium was the period of maximal accumulation of dry matter and showed the maximum efficiency of N, P and K nutrition. For production of 100 kg dry flower 4.13 kg N, 0.37 kg P, 5.03 kg K, 3.03 kg Ca and 0.81 kg Mg were needed. And the ratio of them was 1:0.09:1.22:0.73:0.20.

CONCLUSIONThe period of flower bud differentiation is the most crucial period in the growth of C. morifolium. And it must pay attention to the supply of mineral nutrition and moisture of plant to promote flower formation and dry matter accumulation in this period. It is strongly recommended that the phosphorus and potassium fertilizers should be early applied, the nitrogenous fertilizer should be applied dividedly, and the calcium magnesium fertilizers are also applied properly.

Calcium ; metabolism ; Chrysanthemum ; chemistry ; growth & development ; metabolism ; Nitrogen ; metabolism ; Phosphorus ; metabolism ; Plant Structures ; chemistry ; growth & development ; metabolism ; Potassium ; metabolism

OBJECTIVETo investigate the abnormal abundances of calcium regulatory proteins in rabbit myocytes with failing hearts.

METHODSSixteen rabbits were divided into two groups: 8 rabbits with heart failure induced by volume plus pressure overload and 8 sham-operated animals. The hemodynamic parameters and cardiac structure and function were detected via catheterization and echocardiography respectively. L-type calcium channel (LTCC), Ryanodine receptor 2 (RyR2), Sarcoplasmic reticulum Ca(2+)-ATPase (SERCA2a), and Na(+)-Ca(2+) exchanger (NCX) protein abundances were determined by Western blot analysis.

RESULTSThe ratio of left ventricular mass to body weight, heart rate and left ventricular end diastolic pressure in heart failure rabbits were significantly increased compared with sham-operated rabbits (P < 0.01), but their left ventricular shorten fraction [(21.3 +/- 4.00)% vs. (36.5 +/- 1.36)%] and ejection fraction (0.45 +/- 0.07 vs. 0.70 +/- 0.02) were decreased (P < 0.01). In heart failure rabbits, the abundances of LTCC and RyR2 were significantly decreased (R(LTCC/actin): 0.287 +/- 0.029 vs. 0.624 +/- 0.009; R(RyR2/actin): 0.106 +/- 0.001 vs. 0.203 +/- 0.011; P < 0.01), whereas the expressions of SERCA2a and NCX were markedly increased (R(NCX/actin): 0.497 +/- 0.015 vs. 0.221 +/- 0.014; R(SERCA2a/actin): 0.611 +/- 0.036 vs. 0.433 +/- 0.008; P < 0.01).

CONCLUSIONSReductions of LTCC and RyR2 might contribute to risk factors of systolic dysfunction in failing hearts. In early stage of heart failure, upregulated SERCA2a and NCX protein levels may be helpful for maintaining cardiac performance.

Animals ; Calcium ; metabolism ; Calcium-Binding Proteins ; biosynthesis ; Female ; Heart Failure ; metabolism ; Male ; Rabbits ; Ryanodine Receptor Calcium Release Channel ; metabolism ; Sarcoplasmic Reticulum ; chemistry ; Sarcoplasmic Reticulum Calcium-Transporting ATPases ; metabolism

OBJECTIVETo study the role of Ca2+ overload and energy metabolism in mitochondria in masticatory muscle dysfunctional induced by occlusal trauma.

METHODSMitochondrial Ca2+ contents were measured with atomic emission spectrophotometer. Mitochondrial ATP and ADP contents were measured with high performance liquid chromatography.

RESULTS(1) Mitochondrial Ca2+ contents of masseter muscle ipsilateral to metal splint in ten and twenty days' experimental groups and that contralateral to metal splint in twenty days' experimental group increased significantly (P < 0.05). (2) Mitochondrial ATP contents of masseter muscle ipsilateral to metal splint in experimental groups were higher than that in control groups and contralateral to metal splint after twenty days. (3) Mitochondrial Ca2+ contents of masseter muscle ipsilateral to metal splint were significantly negatively correlated to the mitochondrial ATP contents (r = -0.780, P < 0.05).

CONCLUSIONCa2+ overload in mitochondria depresses ATP production, which results in energy metabolism disorder in masticatory muscle cells. It may play an important role in the mechanism that occlusal trauma results in masticatory muscle dysfunction.

Adenosine Diphosphate ; chemistry ; Adenosine Triphosphate ; chemistry ; Animals ; Calcium ; chemistry ; Energy Metabolism ; Masseter Muscle ; chemistry ; injuries ; Mitochondria, Muscle ; chemistry ; Rabbits

OBJECTIVETo investigate the effect of dentin phosphoprotein (DPP) in inducing dentinal mineralization.

METHODSHuman DPP was combined with EAH-Sepharose 4B beads and its function of inducing mineralization was studied in mineralization system in-vitro. The mineral formed on the surface of the beads was analyzed by scanning electron microscopy (SEM) and the structure was analyzed by X-ray diffraction and plasma emission spectrum.

RESULTSThere was mineral formed on the beads with combined DPP and the mineral was calcium phosphates whose ratio of calcium to phosphate was 1.33. The diffractogram of the formed mineral was more similar to hydroxyapatite than to other calcium phosphates.

CONCLUSIONWhen tightly combined with certain support substance, human DPP can induce mineralization.

Calcium Phosphates ; chemistry ; metabolism ; Dentin ; chemistry ; metabolism ; Dentinogenesis ; Humans ; Microscopy, Electron, Scanning ; Minerals ; chemistry ; metabolism ; Phosphoproteins ; chemistry ; metabolism ; Tooth Calcification ; X-Ray Diffraction

The amyloid β-protein (Aβ)-induced disturbance of intracellular calcium homeostasis has been regarded as the final route whereby Aβ insults neurons. However, the mechanism of Aβ-induced Ca(2+) overloading is still unclear so far. Especially, it remains to be clarified whether nicotinic acetylcholine receptors (nAChRs) are involved in the Aβ-induced elevation of intracellular calcium concentration ([Ca(2+)](i)). In the present study, we observed the effects of Aβ fragments 25-35 (Aβ(25-35)) and 31-35 (Aβ(31-35)) on [Ca(2+)](i) in primary cultured rat cortical neurons using laser-scanning confocal calcium imaging technique, and investigated its probable cholinergic mechanism. The results showed that: (1) Both Aβ(25-35) and Aβ(31-35) induced similar and significant [Ca(2+)](i) elevation in a concentration-dependent manner, and no statistical difference was found between the effects of both peptides; (2) The reverse peptide of Aβ(31-35), i.e. Aβ(35-31), had no effect on [Ca(2+)](i) elevation; (3) Mecamylamine (MCA), a non-specific nAChRs antagonist, significantly and dose-dependently blocked the [Ca(2+)](i) elevation induced by Aβ(25-35) or Aβ(31-35) (4) Dihydro-β-erythroidine (D-β-E), a specific α4β2 subtype nAChRs antagonist, also significantly inhibited the [Ca(2+)](i) elevation induced by Aβ(25-35) and Aβ(31-35), but the effect was weaker than the effect of MCA at the same concentration. These results indicate that Aβ(31-35) may be a shorter active sequence in full length of Aβ molecule, and the overactivation of nAChRs, including α4β2 subtype, may be, at least partly, responsible for the Aβ-induced elevation of [Ca(2+)](i) in cultured rat cortical neurons. Thus, the present study suggests a new potential target of Aβ in the brain, and provides a new insight into the mechanisms by which Aβ impairs the cognitive function in Alzheimer's disease.
Amyloid beta-Peptides ; chemistry ; Animals ; Calcium ; metabolism ; Cells, Cultured ; Neurons ; metabolism ; Peptide Fragments ; chemistry ; Rats ; Receptors, Nicotinic ; metabolism

Large-conductance Ca²⁺-activated K⁺ channels (BK channels) constitute an key physiological link between cellular Ca²⁺ signaling and electrical signaling at the plasma membrane. Thus these channels are critical to the control of action potential firing and neurotransmitter release in several types of neurons, as well as the dynamic control of smooth muscle tone in resistance arteries, airway, and bladder. Recent advances in our understanding of K⁺ channel structure and function have led to new insight toward the molecular mechanisms of opening and closing (gating) of these channels. Here we will focus on mechanisms of BK channel gating by Ca²⁺, transmembrane voltage, and auxiliary subunit proteins.
Animals ; Calcium Signaling ; Cytoplasm ; metabolism ; Electric Conductivity ; Electrophysiological Phenomena ; Humans ; Ion Channel Gating ; Large-Conductance Calcium-Activated Potassium Channels ; chemistry ; metabolism ; Protein Subunits ; chemistry ; metabolism

A new dynamic in vitro intestinal absorption model for screening and evaluating lipid formulations was established by means of the characteristics of the intestinal digestion and absorption of the lipid formulations. This model was composed of two systems, including intestinal digestion and the intestinal tissue culture, which drew the evaluation method of intestinal absorption into the in vitro lipolysis model. The influence of several important model parameters such as Ca2+, D-glucose, K+ on the two systems of this model has been investigated. The results showed that increasing of Ca2+ concentration could be significantly conductive to intestinal digestion. The increasing of D-glucose concentration could stepped significantly down the decay of the intestinal activity. K+ was able to maintain intestinal activity, but the influence of different concentration levels on the decay of the intestinal activity was of no significant difference. Thus the model parameters were set up as follows: Ca2+ for 10 mmol x L(-1), D-glucose for 15 mmol x L(-1) and K+ for 5.5 mmol x L(-1). Type I lipid formulation was evaluated with this model, and there was a significant correlation between the absorption curve in vitro and absorption curve in vivo of rats (r = 0.995 6, P < 0.01). These results demonstrated that this model can be an attractive and great potential method for the screening, evaluating and predicting of the lipid formulations.
Animals ; Calcium ; metabolism ; Caprylates ; chemistry ; Digestion ; Glucose ; metabolism ; Glycerides ; chemistry ; Indomethacin ; chemistry ; Intestinal Absorption ; Lipids ; chemistry ; Lipolysis ; Models, Biological ; Potassium ; metabolism ; Rats ; Rats, Sprague-Dawley

We studied medium alkalinization in Salvia miltiorrhiza suspension cultures treated with salicylic acid and the effect of Ca2+ in this process through application of calcium channel antagonists (Verapamil, LaCl3, LiCl, 2-APB) and ionophore A23187. The results show that salicylic acid could induce significant medium alkalinization in S. miltiorrhiza culture. Verapamil and LaCl3 or LiCl and 2-APB, two different groups of calcium channel antagonist, significantly inhibited the medium alkalinization induced by salicylic acid. However, the suppression effect of verapamil or LaCl3 on medium alkalinization induced by salicylic acid was higher than that of LiCl or 2-APB. When two types of calcium channel inhibitor (LaCl3 and 2-APB) were used together, the medium alkalinization induced by salicylic acid was completely suppressed and even reduced the pH in medium. On the other hand, A23187 could promote the medium alkalinization. Based on the results above, we speculated that salicylic acid could induce significant medium alkalinization in S. miltiorrhiza culture, depending on the calcium from both extracell and intracell. Moreover, calcium from extracell plays a more dominant role in this process. Reveal of relationship in this research between Ca2+ and medium alkalinization can provide theory evidence for mechanism of the plant secondary metabolism.
Calcimycin ; pharmacology ; Calcium ; chemistry ; Calcium Channel Blockers ; pharmacology ; Calcium Ionophores ; pharmacology ; Cell Culture Techniques ; Culture Media ; chemistry ; Salicylic Acid ; pharmacology ; Salvia miltiorrhiza ; metabolism ; Verapamil ; pharmacology

OBJECTIVETo observe the effects of carboxymethyl chitosan calcium (CCC) on concentration of lead, calcium and zinc, and the liver antioxidative capacity in lead poisoned mice.

METHODSMice were randomly divided into 7 groups, including normal group, calcium carbonate group, lead-model group, and three experimental groups treated with CCC in three different doses, and the CaNa2EDTA positive control group. The lead poisoned mice model was established by giving water contained with lead acetate. CCC was administrated to mice i.g. once a day. Thirty days later, mice were killed and the concentrations of lead, calcium and zinc in blood, liver, brain and femur were determined by atomic absorption spectrophotometer. Maleic dialdehyde (MDA), total antioxidative capacity (T-AOC), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activities in liver were measured by using assay kit.

RESULTSCCC significantly reduced the concentration of lead in blood, brain, liver and femur from about 1.56 microg/g, 13.38 microg/g, 16.15 microg/g, 1011.62 microg/g to about 0.50 microg/g, 5.57microg/g, 5.64 microg/g, 457.86 microg/g, and markedly increased the concentration of calcium in femur in lead poisoned mice. CCC had no significant side-effects on concentration of zinc in lead poisoned mice. The antioxidative profile was favorably changed as manifested by decreasing the level of MDA, increasing the activities of SOD, GSH-Px and T-AOC in livers of the in lead poisoned mice.

CONCLUSIONCCC might significantly advance the excretion of lead, increase the concentration of calcium in femur and the antioxidative capacity in lead-loaded mice.

Animals ; Brain Chemistry ; Calcium ; metabolism ; Chitosan ; analogs & derivatives ; pharmacology ; Female ; Femur ; chemistry ; Lead ; metabolism ; Lead Poisoning ; metabolism ; Liver ; chemistry ; Mice ; Mice, Inbred Strains ; Zinc ; metabolism

This study was amid to construct the pharmacophore model of L-type calcium channel antagonist in the application of screening Drugbank and TCMD. This paper repositions the approved drugs resulting from virtual screening and discusses the relocation-based drug discovery methods, screening antihypertensive drugs with L-type calcium channel function from TCMD. Qualitative hypotheses wre generated by HipHop separately on the basis of 12 compounds with antagonistic action on L-type calcium channel expressed in rabbit cardiac muscle. Datebase searching method was used to evaluate the generated hypotheses. The optimum hypothesis was used to search Drugbank and TCMD. This paper repositions the approved drugs and evaluates the antihypertensive effect of the chemical constituent of traditional Chinese medicine resulting from virtual screening by the matching score and literature. The results showed that optimum qualitative hypothesis is with six features, which were two hydrogen-bond acceptors, four hydrophobic groups, and the CAI value of 2.78. Screening Drugbank achieves 93 approved drugs. Screening TCMD achieves 285 chemical constituents of traditional Chinese medicine. It was concluded that the hypothesis is reliable and can be used to screen datebase. The approved drugs resulting from virtual screening, such as pravastatin, are potentially L-type calcium channels inhibitors. The chemical constituents of traditional Chinese medicine, such as Arctigenin III and Arctigenin are potentially antihypertensive drugs. It indicates that Drug Repositioning based on hypothesis is possible.
Animals ; Antihypertensive Agents ; chemistry ; pharmacology ; Calcium Channel Blockers ; chemistry ; pharmacology ; Calcium Channels, L-Type ; genetics ; metabolism ; Drug Repositioning ; methods ; Molecular Structure ; Myocardium ; metabolism ; Rabbits