Reduced Ca Levels Research Articles

The Trace Kynurenine, Cinnabarinic Acid, Displays Potent Antipsychotic-Like Activity in Mice and Its Levels Are Reduced in the Prefrontal Cortex of Individuals Affected by Schizophrenia.

Cinnabarinic acid (CA) is a kynurenine metabolite that activates mGlu4 metabotropic glutamate receptors. Using a highly sensitive ultra-performance liquid chromatography/tandem mass spectrometry (UPLC/MS-MS) method, we found that CA is present in trace amounts in human brain tissue. CA levels were largely reduced in the prefrontal cortex (PFC) of individuals affected by schizophrenia. This reduction did not correlate with age, sex, duration of the disease, and duration and type of antipsychotic medication and might, therefore, represent a trait of schizophrenia. Interestingly, systemic treatment with low doses of CA (<1 mg/kg, i.p.) showed robust efficacy in several behavioral tests useful to study antipsychotic-like activity in mice and rats and attenuated MK-801-evoked glutamate release. CA failed to display antipsychotic-like activity and inhibit excitatory synaptic transmission in mice lacking mGlu4 receptors. These findings suggest that CA is a potent endogenous antipsychotic-like molecule and reduced CA levels in the PFC might contribute to the pathophysiology of schizophrenia.

Effect of a high dose of exogenous phytase and supplementary myo-inositol on mineral solubility of broiler digesta and diets subjected to in vitro digestion assay.

This study was conducted to evaluate the effect of microbial phytase and myo-inositol supplementation in low non-phytate phosphorus (nPP) diets on pH and the solubility of minerals in an in vitro digestion procedure (IVDP) and to compare this with digesta from birds fed different diets (grower diets) compared to the in vitro test (starter diets). A total of 660 1-day-old broilers were randomly allotted into 11 dietary treatments and fed a corn-soybean-meal-based diet with recommended nPP (positive control; PC), an nPP-deficient diet (negative control; NC), NC diets supplemented with phytase (500; 1,000; 2,000; 3,000; 4,000; 5,000; and 6,000 FTU/kg), an NC diet plus 0.15% myo-inositol, and an NC diet with reduced Ca level (Ca: nPP ratio same as PC) from 1 to 23 D of age. The pH and Ca solubility of the NC diet was increased compared with the PC when subjected to IVDP (P < 0.05). P solubility in the gizzard and jejunal digesta was reduced in the NC compared with the PC diet and this was also reflected in the IVDP. Phytase addition to the NC diets linearly increased (P < 0.05) the pH value and Ca and P solubilities in both digesta and diets subjected to IVDP. Higher doses of microbial phytase increased (P < 0.05) Zn and Fe solubilities in both digesta and IVDP. Myo-inositol supplementation of the NC diet had no effect on mineral solubility, but decreased (P < 0.05) the pH of the IVDP. Lowering the Ca content of the NC diet decreased (P < 0.05) the pH of the in vitro digested diets and Ca solubility in both broiler digesta and IVDP and also increased (P < 0.05) P solubility in both the jejunal digesta and IVDP. Correlations were noted between the solubility of P in the in vitro assay and that in the gizzard and jejunal digesta, and also with bird performance, confirms the usefulness of in vitro assay.

Cooperative effects of pre-harvest calcium and gibberellic acid on tissue calcium content, quality attributes, and in relation to postharvest disorders of late-maturing sweet cherry

Six Ca(NO3)2 sprays at 0.3% and 0.6% from pit hardening (PH) to 1 week before harvest (1WBH) most effectively increased Ca uptake in sweet cherry (Prunus avium). Low concentration (<0.3%) did not affect the absorption of Ca; high concentration (> 1.6%) caused burning of leaf margins. Fruit treated with Ca had greater fruit firmness (FF), soluble solids content (SSC) and titratable acidity (TA) and fewer disorders than untreated fruit while retaining marketable color and size. A single, low concentration of GA3 combined with Ca sprays enhanced Ca uptake, cracking resistance, and FF without delaying maturation. When Ca plus GA3 sprays were reduced to four times, Ca uptake was retarded, but had an equal or greater benefit than Ca sprays alone. The 5-d harvest delay in combination-treated fruit did not affect skin color, but these fruit had reduced Ca levels at harvest and displayed stem browning after storage.

The influence of selected feed additives on mineral utilisation and bone characteristics in laying hens

Abstract The trial with 240 caged ISA Brown laying hens was performed to evaluate the effect of selected feed additives on mineral utilisation as well as biomechanical (breaking strength, yielding load, stiffness) and geometrical (cortex thickness, cross-section area, weight, length) indices of tibia and femur bones. At 26 wks of age the layers were randomly assigned to 10 treatments with 12 replicates (cages) of two birds. In the study a 2 × 5 experimental scheme was used i.e. to 70 wks of age, the layers were fed isocaloric and isonitrogenous experimental diets containing reduced (3.20%) or standard (3.70%) Ca level. The diets with both Ca levels were either not supplemented, or supplemented with the studied feed additives i.e. sodium butyrate, probiotic bacteria, herbal extract blend and chitosan. There were no statistically significant effects of the experimental factors on the indices of the tibia bones. However, the diet with reduced Ca level decreased bone breaking strength, yielding load, stiffness, and mineralisation of the femur bones (P&lt;0.05). The majority of used feed supplements, i.e. probiotic, herb extracts, and chitosan, increased biomechanical indices (breaking strength and yielding load) and mineralisation of the femur bones (P&lt;0.05). Neither dietary Ca level nor feed additives affected dry matter, organic matter, ether extract, N-free extracts, crude fibre and ash digestibility, and P retention and excretion; however, Ca excretion and retention was lower in the hens fed the diets with reduced Ca level (P&lt;0.05). Relative Ca retention (Ca retained as % of Ca intake) was improved by diet supplementation with probiotic, herb extracts and chitosan (P&lt;0.05). In conclusion, this study has shown that decreased Ca dietary level (3.20%) can negatively affect bone quality in layers, while probiotic, herb extracts and chitosan addition may improve the selected biomechanical indices of the femurs, irrespective of Ca dietary concentration.

Use of Metal-Rich Slag as a Source of Grit and Its Effects on Pigeon Health and Fitness

Uptake, utilization and physiological effects of slag as a source of grit were studied in laboratory pigeons provided with an ad libitum supply of a) industrial metal-rich slag b) pristine gravel or c) a combination of the above, over a one-year period. Although retention times undoubtedly differed, both grit types appeared to remain within the gizzard until near-completely abraded, thus resulting in near-maximal exposure of the bird to intrinsic metal loads present. Mortalities were confined to the slag-treated group (62%) and birds given choice (11%) with no deaths among gravel-treated controls. Surviving slag-treated birds indicated marked weight increases in both liver (2-fold) and kidney (~ 46%) whereas body fat scores and breast muscle mass were substantially reduced. Slag ingestion likewise affected marked hypertrophy of the parathyroid glands. Tissue metal assays indicated a striking accumulation of Fe (7-8 fold) in liver, and to a lesser extent in bone (3.2-fold) and kidney (1.5-fold) of slag-treated birds. Histologically, hepatocytes and invading clusters of macrophages appeared stuffed with numerous pigmented cytoplasmic granules – histochemically identified as predominantly stored Fe. These findings point to the development of an acute toxic Fe storage condition, not unlike avian hemosiderosis (iron storage disease), as the prime cause of morbidity and eventually death of these slag-treated birds. Long bones of slag-treated birds were substantially more pliable, of reduced strength, and characterized by significantly reduced Ca levels compared to control birds. Histological examination of keel and tibiotarsal bones revealed moderate to severe mineral resorption, with thinning of cortical layers in lamellar bone and reduced cross-strut formation in cancellous bone. Evidence of active woven bone formation at these foci was likewise confirmed, thus corroborating the marked hypertrophy of parathyroids and implied changes in parathyroid function. Given free choice, birds were basically non-selective, rather than exclusive, in their uptake of gravel versus slag. Given that slag was not avoided, and in light of its profound adverse physiological effects, concern for the ecological implications of the vast quantities of exposed slag within our environment and its potential health risks to wild bird populations is warranted.

Effects of a high dose of microbial phytase and myo-inositol supplementation on growth performance, tibia mineralization, nutrient digestibility, litter moisture content, and foot problems in broiler chickens fed phosphorus-deficient diets

A total of 660 one-day-old Ross 308 broiler chicks were randomly distributed into eleven dietary treatments. Treatments included a maize-soybean meal-based diet with recommended calcium (Ca) and non-phytate phosphorus (nPP) (positive control; PC), an nPP-deficient diet (negative control; NC), NC diets supplemented with different levels of phytase (0, 500, 1,000, 2,000, 3,000, 4,000, 5,000, and 6,000 FTU/kg), a NC diet plus 0.15% myo-inositol, and a NC diet with reduced Ca level (Ca to nPP ratio same as PC). Feeding the NC diet had no effects on birds' body weight (BW), weight gain (WG), feed intake (FI), and feed conversion ratio (FCR), but decreased (P <0.05) tibia P contents, crude protein (CP) digestibility, and serum P, but increased (P <0.05) serum alkaline phosphatase (ALP) activity at 21 d of age. Phytase supplementation at ≥4,000 FTU/kg improved (P <0.05) BW, WG and digestibility of nutrients. Feeding the NC diet resulted in greater (P <0.05) litter moisture content (42 d) and poorer gait score (21 d), but 4,000 and 6,000 FTU/kg phytase returned (P <0.05) these parameters to that of the PC. Supplemental myo-inositol increased (P <0.05) serum total protein, P retention, and decreased (P <0.05) litter moisture at 42 d of age. Feeding the low Ca NC diet increased (P <0.05) serum total protein, ileum Ca, P, and CP digestibility and decreased serum ALP activity, litter moisture and gait score compared to the NC group. In conclusion, phytase in a dose-dependent manner, especially at ≥4,000 FTU/kg levels, was effective in overcoming the negative consequences of NC diets, primarily due to the ability to improve nutrient utilization. In addition, reducing the Ca level or supplementation of inositol of NC diet can correct some the negative effects of feeding a NC diet confirming the negative effect of a wide Ca: P ratio in a P-deficient diet and suggesting that inositol may play a role in the response to phytase addition.

Reduction of inorganic phosphate-induced human smooth muscle cells calcification by inhibition of protein kinase A and p38 mitogen-activated protein kinase

High levels of serum phosphate are associated with calcification of human smooth muscle cells (HSMCs). We investigated whether inhibition of protein kinase A (PKA) and mitogen-activated protein kinase (MAPK) signals [p38, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK)] can reduce inorganic phosphate (Pi)-induced HSMC calcification. Inhibition of PKA or p38 MAPK by inhibitors or small interfering RNAs (siRNAs) reduced Ca levels and alkaline phosphatase activities in HSMCs treated with high Pi, but inhibition of ERK1/2 and JNK showed no significant changes. Moreover, there were no significant changes in cell viability on adding siRNAs and three inhibitors (PKA, p38, and MEK1/2), but JNK inhibitor slightly reduced cell viability. These results show that PKA and p38 MAPK are involved in the Pi-induced calcification of HSMCs, and may be good targets for reducing vascular calcification.

Interactive effects of calcium decline and predation risk on the potential for a continuing northward range expansion of the rusty crayfish (Orconectes rusticus)

Over the last three decades, the rusty crayfish (Orconectes rusticus (Girard, 1852)) has been expanding its range northward via human-mediated dispersal. If this species is to continue expanding its range northward, it will move onto the Canadian Shield, where calcium (Ca) availability is low and is predicted to decline further in the future. Dissolved Ca is a vital functional component of mollusc and crustacean physiology, important for exoskeletal condition and strength, as well as metabolic activity. However, some organisms are able to compensate for reduced structural integrity by modifying their behaviour. In this study, we asked if the invasive O. rusticus can survive low levels of ambient Ca and, if it can, whether it exhibits modified antipredator behavior in response to the physiological limitations imposed by low [Ca]. We found that, under reduced Ca levels, O. rusticus reduced the frequency of standard activities (such as grooming and foraging) and was more likely to engage in vigilance and (or) escape behavior. We also found that some individuals, in extremely low [Ca], died while molting. This study suggests that Ca limitation on the Shield, especially where predators are present, may limit the northward expansion of O. rusticus beyond their current range limit.

Hypercalcemia in patients with oral squamous cell carcinoma.

Humoral hypercalcemia of malignancy (HHM) is one of the most common metabolic complications associated with cancer. A retrospective study of hypercalcemia in patients with squamous cell carcinoma of the oral cavity was undertaken. All patients were periodically monitored for their serum level of calcium (Ca). Hypercalcemia was defined as a serum Ca concentration higher than 11 mg/dl of the correction for serum albumin concentration. The serum levels of parathyroid hormone related protein (PTH-rP) were also measured by radioimmunoassay. Hypercalcemia was detected in ten of 246 patients (4.1%). All ten patients were at an advanced stage of oral squamous cell carcinoma (SCC, Stage IVA, IVB or IVC). In these ten patients, the serum level of PTH-rP was significantly elevated, 238 +/- 91 pmol/l (range, 108-380 pmol/L). The patients with HHM who underwent antihypercalcemic therapy showed reduced Ca levels relating to PTH-rP levels; however, the Ca concentration was temporarily improved after anti-hypercalcemic treatment. The median survival time after diagnosis of HHM was only 55.8 +/- 19.9 days (range, 27-86 days). HHM in oral cancer is likely attributable to PTH-rP, and its occurrence appears to be an ominous prognostic sign.

Interrelationships among Turfgrasses, Clipping Recycling, Thatch, and Applied Calcium, Magnesium, and Potassium

AbstractThe influence of clipping return on bermudagrass thatch has not been resolved. Additionally, independent and combined effects of applied Ca, Mg, and K on bermudagrass growth and quality and thatch accumulation have not been clarified. To evaluate the influence of clipping return and applied Ca, Mg, and K on ‘Tifway’ bermudagrass (Cynodon dactylon (L.) Pers. × Cynodon transvaalensis Burtt Davy) and ‘Pennant’ perennial ryegrass (Lolium perenne L.) a 3‐y study was conducted at the Turfgrass Field Laboratory near Gainesville, FL, on an Arredondo loamy fine sand (Typic Quartzipsammets). A strip‐split‐plot factorial experiment with applied Ca, Mg, and K at 20 g m−2 representing the main plot and with clipping return or removal stripped across the main plots with three replications was employed. Bermudagrass clipping return did not affect overall mean thatch accumulation. Bermudagrass and perennial ryegrass clipping yields increased in response to clipping return. Bermudagrass quality was enhanced by the return of clippings, but ryegrass quality was not. Application of Ca and K did not influence thatch accumulation, while Mg did promote additional bermudagrass thatch. Application of K and Mg reduced Ca levels on plots receiving Ca to less than the extractable Ca level of the untreated plots. Ryegrass and bermudagrass quality was increased by the application of Mg on plots which had the clippings removed. Potassium and Mg application promoted bermudagrass clipping yield when clippings were removed. Soil Ca to Mg ratio did not influence the growth or quality of either bermudagrass or ryegrass.