scholarly journals Promoting the Calcium-Uptake Bioactivity of Casein Phosphopeptides in vitro and in vivo

2021 ◽  
Vol 8 ◽  
Author(s):  
Guo Liu ◽  
Baoyan Guo ◽  
Shengwei Sun ◽  
Minna Luo ◽  
Fei Liu ◽  
...  
Keyword(s):  
Calcium Binding ◽  
Calcium Transport ◽  
Calcium Uptake ◽  
Calcium Absorption ◽  
Serum Alkaline Phosphatase ◽  
Binding Capacity ◽  
Animal Experiments ◽  
Casein Phosphopeptides

Casein phosphopeptides have been studied widely for their ability to chelate calcium. However, systematic studies on the effects of casein phosphopeptides (CPP) on calcium absorption in vitro and in vivo are scarce. The purities of two commercially available products, CPP1 and CPP2, are 18.37 and 25.12%, respectively. Here, the in vitro calcium binding capacity of CPP2 was 142.56 ± 7.39 mg/g, which was higher than that of CPP1 (107.15 ± 6.27 mg/g). The calcium transport results in a Caco-2 monolayer model indicated that, relative to controls, CPP1 and CPP2 increased calcium transport by 21.78 and 53.68%, respectively. Subsequent animal experiments showed that the CPP2-Ca-H group (1% Ca, 0.4% CPP2) had significant increases in the femur index, serum Ca2+ and serum osteocalcin levels, and femoral Ca content. The CPP2-Ca-H animal also had decreased serum alkaline phosphatase levels, parathyroid hormone content, and urinary pyridinoline content. Overall, our results demonstrated that CPP2 had stronger effects on promoting calcium uptake than CPP1.

Effects of casein phosphopeptides on calcium absorption and metabolism bioactivity in vitro and in vivo

2018 ◽  
Vol 9 (10) ◽  
pp. 5220-5229 ◽  
Author(s):  
Shengwei Sun ◽  
Fei Liu ◽  
Guo Liu ◽  
Jianyin Miao ◽  
Hang Xiao ◽  
...  
Keyword(s):  
Calcium Metabolism ◽  
Calcium Uptake ◽  
Calcium Absorption ◽  
Casein Phosphopeptides

CPP1, CPP2 and P5 promoted calcium uptake in Caco-2 cells and affected isotopic calcium metabolism in rats.

Activity-Related Calcium Dynamics in Motoneurons of the Nucleus Hypoglossus From Mouse

1999 ◽  
Vol 82 (6) ◽  
pp. 2936-2946 ◽  
Author(s):  
Mario B. Lips ◽  
Bernhard U. Keller
Keyword(s):  
Quantitative Analysis ◽  
Action Potential ◽  
Calcium Binding ◽  
Calcium Influx ◽  
Binding Capacity ◽  
Calcium Transients ◽  
Calcium Dynamics ◽  
The Brain

A quantitative analysis of activity-related calcium dynamics was performed in motoneurons of the nucleus hypoglossus in the brain stem slice preparation from mouse by simultaneous patch-clamp and microfluorometric calcium measurements. Motoneurons were analyzed under in vitro conditions that kept them in a functionally intact state represented by rhythmic, inspiratory-related bursts of excitatory postsynaptic currents and associated action potential discharges. Bursts of electrical activity were paralleled by somatic calcium transients resulting from calcium influx through voltage-activated calcium channels, where each action potential accounted for a calcium-mediated charge influx around 2 pC into the somatic compartment. Under in vivo conditions, rhythmic-respiratory activity in young mice occurred at frequencies up to 5 Hz, demonstrating the necessity for rapid calcium elevation and recovery in respiratory-related neurons. The quantitative analysis of hypoglossal calcium homeostasis identified an average extrusion rate, but an exceptionally low endogenous calcium binding capacity as cellular parameters accounting for rapid calcium signaling. Our results suggest that dynamics of somatic calcium transients 1) define an upper limit for the maximum frequency of respiratory-related burst discharges and 2) represent a potentially dangerous determinant of intracellular calcium profiles during pathophysiological and/or excitotoxic conditions.

Effect of hypophysectomy on calcium transport by rat duodenum.

1977 ◽  
Vol 232 (2) ◽  
pp. E229
Author(s):  
E L Krawitt ◽  
A S Kunin ◽  
H W Sampson ◽  
B F Bacon
Keyword(s):  
Calcium Transport ◽  
Calcium Absorption ◽  
Plasma Flux ◽  
Perfusion Technique ◽  
Intestinal Length ◽  
Absorption Studies ◽  
Luminal Perfusion ◽  
Rat Duodenum

To examine the effect of hypophysectomy on intestinal calcium absorption, studies were performed on immature rats 7, 14, and 21 days after hypophysectomy. Duodenal calcium transport was measured in vitro utilizing everted gut sacs and in vivo by a luminal perfusion technique. Hypophysectomy produced no differences in the ability of everted gut sacs to transport calcium. Similarly, when in vivo transport data were expressed on the basis of intestinal length, no significant differences were noted. However, when transport data were expressed on the basis of mucosal weight, increases in absorption and lumen-to-plasma fluxes were apparent in hypophysectomized animals. No differences were seen in plasma-to-lumen fluxes. The results indicate that when the transport data are corrected for mass of intestinal mucosa, the duodenum from hypophysectomized animals absorbs calcium more avidly due to an increase in lumen-to-plasma flux.

Identification of Casein Phosphopeptides in β-casein and Commercial Hydrolysed Casein by Mass Spectrometry

2006 ◽  
Vol 12 (5) ◽  
pp. 379-384 ◽  
Author(s):  
E. Miquel ◽  
J. A. Gómez ◽  
A. Alegría ◽  
R. Barberá ◽  
R. Farré ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Binding Capacity ◽  
Amino Acid Sequences ◽  
Gastrointestinal Digestion ◽  
Simulated Gastrointestinal Digestion ◽  
Casein Phosphopeptides ◽  
Hydrolysed Casein ◽  
Cluster Sequence

Casein phosphopeptides (CPPs) in commercial hydrolysed casein (CE90CPP) and in β-CN (β-CN) after simulated gastrointestinal digestion (gastric stage pepsin, pH =2, 37°C 2h) and intestinal stage (pancreatic-bile extract, pH =5.2, 37°C 2h) were sequenced by on-line reversed-phase high performance liquid chromatography coupled to electrospray ionisation tandem mass spectrometry (RP-HPLC-ESIMS/MS). In β-CN digest five peptides that contained four to five phosphate groups and the cluster sequence SpSpSpEE (residues 17-21) were identified. All CPPs with one exception β-CN(1-24)4P, had the protein fragment β-CN(1-25)4P, which is one of the main CPPs produced in vivo digestion of casein and the results of in vitro studies showed that this fragment enhanced calcium, iron and zinc absorption. In commercial hydrolysed casein CE90CPP 13 peptides were identified, only one of them, αs2-CN (1-13)3P, contained the cluster sequence SpSpSpEE but all the peptides have one or two phosphoserine residues with mineral binding capacity. These CPPs were shorter (527-2061 Da vs 2966-6512 Da) and less phosphorylated (1-3 P vs 4-5 P) than those released after simulated gastrointestinal digestion of β-CN. In both samples, the potential mineral chelating properties of these peptides in relation to their amino acid sequences and the presence of the phosphorylated cluster are discussed.

Glucose enhancement of transcellular calcium transport in the intestine

1988 ◽  
Vol 255 (3) ◽  
pp. G339-G345 ◽  
Author(s):  
K. M. Carroll ◽  
R. J. Wood ◽  
E. B. Chang ◽  
I. H. Rosenberg
Keyword(s):  
Calcium Transport ◽  
Calcium Uptake ◽  
Calcium Absorption ◽  
Membrane Integrity ◽  
Calcium Flux ◽  
Calcium Efflux ◽  
Cell Membrane Integrity ◽  
Active Calcium ◽  
Altered Cell

Glucose stimulates calcium transport in vitro in rat duodenal tissue and isolated enterocytes. Under short-circuited conditions, glucose increased mucosal to serosal calcium flux (JCa(m----s)) without altering serosal to mucosal calcium flux (JCa(s----m)) in the duodenum, the primary site of active calcium absorption in the rat small intestine. The half-maximal dose (ED50) of the glucose stimulatory effect was less than 1 mM, and an increase in JCa(m----s) of 80% over control was seen at a glucose concentration of 50 mM. Glucose did not increase calcium flux in the ileum where active calcium absorption is minimal. Glucose stimulated net calcium uptake by 35% in isolated duodenal enterocytes. Glucose did not alter calcium efflux from preloaded enterocytes suspended in calcium-free buffer. Glucose enhancement of net calcium uptake in enterocytes was not caused by altered cell membrane integrity or functional viability. The nonmetabolizable glucose analogue alpha-methylglucoside did not stimulate calcium transport. Our findings suggest that glucose can stimulate intestinal calcium absorption, at least partially, by enhancing transcellular calcium transport and that cellular glucose metabolism is necessary for stimulation of this route of calcium transport.

Calcium-transport function of the chick embryonic chorioallantoic membrane. I. In vivo and in vitro characterization

1986 ◽  
Vol 82 (1) ◽  
pp. 73-84
Author(s):  
R.S. Tuan ◽  
M.J. Carson ◽  
J.A. Jozefiak ◽  
K.A. Knowles ◽  
B.A. Shotwell
Keyword(s):  
Calcium Transport ◽  
Calcium Uptake ◽  
Chorioallantoic Membrane ◽  
Transport Function ◽  
In Ovo ◽  
In Vitro Characterization ◽  
Microsomal Membranes

During chick embryonic development, the chorioallantoic membrane (CAM) is responsible for the mobilization of shell calcium into the embryonic circulation. The calcium-transport function of the CAM was studied here by measuring CAM calcium uptake in vivo and in vitro. The in vivo technique involved the use of an uptake chamber constructed on top of the CAM in situ. The in vitro methods included two systems: CAM tissue disks and cell-free microsomal membranes isolated from the CAM. Analyses using these three assays show that calcium uptake by the CAM exhibited characteristics indicative of active transport, such as temperature dependence, saturability, energetic requirement and ion specificity. The data also show that calcium-uptake activities of the CAM increase as a function of embryonic age in a manner coincident with the increased accumulation of calcium by the developing embryo in ovo.

In vivo transport of calcium from healed Thiry-Vella fistulas in dogs

1962 ◽  
Vol 202 (1) ◽  
pp. 161-164 ◽  
Author(s):  
Carl F. Cramer ◽  
John Dueck
Keyword(s):  
Calcium Transport ◽  
Absorption Rate ◽  
Calcium Absorption ◽  
Carrier System ◽  
Absorption Data ◽  
Physiological Factors ◽  
Low Concentrations ◽  
Maximal Absorption

Calcium transport was studied in vivo in dogs by perfusing solutions of various calcium concentrations through healed jejunal Thiry-Vella fistulas. The method is simple, quantitative, and it avoids a number of difficulties of interpretation inherent in tracer and in vitro studies. At quite low concentrations the rate of Ca absorption was approximately proportional to Ca concentration, but at higher concentration the rate fell off continuously. Above 12.5 mm/liter the absorption rate remained constant at approximately 0.5 mm/hr. There was some variation from week to week in the same dog and between different dogs. However, in 30 runs on 10 dogs this maximum absorption rate averaged 18.5 ± 1.1 mg Ca/hr. Simultaneous administration of magnesium depressed maximum Ca absorption of 9.3 mg Ca/hr. The calcium absorption data conformed to the Michaelis-Menten equation. The approach to a maximal absorption rate with increasing Ca concentration, the Mg competition, and the conformity to the Michaelis-Menten kinetics all suggest that Ca is absorbed by a carrier system which may involve either active or facilitated transport. The method lends itself to studies of physiological factors which may affect calcium absorption.

scholarly journals Calcium isotope fractionation by osteoblasts and osteoclasts, across endothelial and epithelial cell barriers and with binding to proteins

2021 ◽  
Author(s):  
Eva Teresa Toepfer ◽  
Jeremy Rott ◽  
Maria Bartosova ◽  
Ana Kolevica ◽  
Irma Machuca-Gayet ◽  
...  
Keyword(s):  
Calcium Binding ◽  
Calcium Transport ◽  
Bone Mineralization ◽  
Calcium Balance ◽  
Calcium Isotope ◽  
Diagnosis Of Osteoporosis ◽  
Osteoblast Activity ◽  
Proximal Tubular

Timely and accurate diagnosis of osteoporosis is essential for adequate therapy. Calcium isotope ratio (δ44/42Ca) determination has been suggested as a sensitive, non-invasive and radiation-free biomarker for the diagnosis of osteoporosis, reflecting bone calcium balance. The quantitative diagnostic is based on the calculation of the δ44/42Ca difference between blood, urine and bone. The underlying cellular processes, however, have not been studied systematically. We quantified calcium transport and δ44/42Ca fractionation during in-vitro bone formation and resorption by osteoblasts and osteoclasts and across renal proximal tubular epithelial cells (HK-2), endothelial cells (HUVEC) and enterocytes (Caco-2) in transwell systems, and determined transepithelial electrical resistance characteristics. δ44/42Ca fractionation was furthermore quantified with calcium binding to albumin and collagen. Calcified matrix formed by osteoblasts was isotopically lighter than culture medium by -0.27 ± 0.03‰ within 5 days, while a consistent effect of activated osteoclasts on δ44/42Ca could not be demonstrated. A transient increase in δ44/42Ca in the apical compartment by 0.26‰ occured across HK-2 cells, while δ44/42Ca fractionation was small across the HUVEC barrier, and absent with Caco-2 enterocytes, and with binding of calcium to albumin and collagen. In conclusion, δ44/42Ca fractionation follows similar universal principles as during inorganic mineral precipitation; osteoblast activity results in δ44/42Ca fractionation. δ44/42Ca fractionation also occurs across the proximal tubular cell barrier and needs to be considered for in-vivo bone mineralization modelling. In contrast, the effect of calcium transport across endothelial and enterocyte barriers on blood δ44/42Ca should be low and is absent with physiochemical binding of calcium to proteins.

Bioactive peptide isolated from casein phosphopeptides promotes calcium uptake in vitro and in vivo

2018 ◽  
Vol 9 (4) ◽  
pp. 2251-2260 ◽  
Author(s):  
Guo Liu ◽  
Shengwei Sun ◽  
Baoyan Guo ◽  
Benchun Miao ◽  
Zhen Luo ◽  
...  
Keyword(s):  
Calcium Uptake ◽  
Bioactive Peptide ◽  
Casein Phosphopeptides ◽  
Transcellular Pathway ◽  
Bone Calcification ◽  
In Cells

A monomeric peptide isolated from casein phosphopeptides promoted calcium uptake in cells via the transcellular pathway and was beneficial for bone calcification in rats.

Abstract P401: The Anti-arrhythmic Effects Of VDAC Isoforms Are Mediated By Glutamate 73 Through Regulation Of Mitochondrial Calcium Transport

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Lauren Crisman ◽  
Hirohito Shimizu ◽  
Adam Langenbacher ◽  
Jie Huang ◽  
Kevin Wang ◽  
...  
Keyword(s):  
Calcium Transport ◽  
Calcium Uptake ◽  
Calcium Overload ◽  
Mitochondrial Calcium ◽  
Cellular Processes ◽  
Excess Calcium ◽  
Evolutionarily Conserved ◽  
Mitochondrial Calcium Uptake

Mitochondria critically regulate cellular processes such as bioenergetics, metabolism, calcium homeostasis and apoptosis. VDAC proteins are abundant proteins that control the passage of ions and metabolites across the outer mitochondrial membrane. We have previously shown that activation of VDAC2, is able to buffer excess calcium and thereby suppress calcium overload induced arrhythmogenic events in vitro and in vivo. However, the mechanism by which VDAC2 regulates calcium transport and cardiac contractions remained unclear. It is also unclear whether all three VDAC isoforms (VDAC1,2 and 3) possess similar cardioprotective activity. The zebrafish tremblor/ncx1 mutant lacks functional NCX1 in cardiomyocytes leading to calcium overload, and the manifestation of fibrillation-like phenotypes. Using the tremblor/ncx1 mutant as a model, we observed isoform-specific differences between the VDAC family members. VDAC1 and VDAC2 enhanced mitochondrial calcium trafficking and restore rhythmic contraction in tremblor mutants, whereas, VDAC3 did not. We found that the differing rescue capabilities of VDAC proteins were dependent upon residues in their N-terminal halves. Phylogenetic analysis further revealed the presence of an evolutionarily conserved glutamate at position 73 (E73) within VDAC1 and VDAC2, but a glutamine (Q73) in VDAC3. Excitingly, we showed that replacing VDAC2 E73 with Q73 ablated its calcium transporting activity. Conversely, substituting the Q73 with E73 allows VDAC3 to gain calcium trafficking and cardioprotective abilities. Overall, our study demonstrates an essential role for the evolutionarily conserved glutamate-73 in determining the anti-arrhythmic effect of VDAC isoforms through their regulation of mitochondrial calcium uptake.

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