scholarly journals Candidate genes of the transcellular and paracellular calcium absorption pathways in the small intestine of laying hens

2019 ◽  
Vol 98 (11) ◽  
pp. 6005-6018 ◽  
Author(s):  
A Gloux ◽  
N Le Roy ◽  
A Brionne ◽  
E Bonin ◽  
A Juanchich ◽  
...  
2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Shun Li ◽  
Juan Li ◽  
Jiawei Tian ◽  
Ranran Dong ◽  
Jin Wei ◽  
...  

CDKN1C and NAP1L4 in human CDKN1C/KCNQ1OT1 imprinted domain are two key candidate genes responsible for BWS (Beckwith-Wiedemann syndrome) and cancer. In order to increase understanding of these genes in pigs, their cDNAs are characterized in this paper. By the IMpRH panel, porcine CDKN1C and NAP1L4 genes were assigned to porcine chromosome 2, closely linked with IMpRH06175 and with LOD of 15.78 and 17.94, respectively. By real-time quantitative RT-PCR and polymorphism-based method, tissue and allelic expression of both genes were determined using F1 pigs of Rongchang and Landrace reciprocal crosses. The transcription levels of porcine CDKN1C and NAP1L4 were significantly higher in placenta than in other neonatal tissues (P<0.01) although both genes showed the highest expression levels in the lung and kidney of one-month pigs (P<0.01). Imprinting analysis demonstrated that in pigs, CDKN1C was maternally expressed in neonatal heart, tongue, bladder, ovary, spleen, liver, skeletal muscle, stomach, small intestine, and placenta and biallelically expressed in lung and kidney, while NAP1L4 was biallelically expressed in the 12 neonatal tissues examined. It is concluded that imprinting of CDKN1C is conservative in mammals but has tissue specificity in pigs, and imprinting of NAP1L4 is controversial in mammalian species.


2000 ◽  
Vol 71 (2) ◽  
pp. 171-177
Author(s):  
Takaharu KOZAKAI ◽  
Emi KONNO ◽  
Yasuyuki SASAKI ◽  
Kazuo KATOH

1983 ◽  
Vol 49 (1) ◽  
pp. 67-76 ◽  
Author(s):  
Yeon Sook Lee ◽  
Tadashi Noguchi ◽  
Hiroshi Naito

1. In an attempt to investigate calcium absorption in the rat during the postprandial period, with the least alteration of the physical environment, the undisturbed small intestine was ligated in situ 2·5 or 3·0 h after ingestion of a diet containing 200 g casein/kg or an equivalent amino acid mixture, or 925 g casein/kg. Estimation of Ca absorption was made by comparing the amount of soluble 40Ca or 45Ca in the contents of segments from the rats receiving 45Ca by intubation 30 min after withdrawal of food, ligated after a further 30 min, then killed after 0 or 30 min.2. Under conditions such that the estimated amount of a marker, polyethylene glycol, in segments ligated in a defined position was little changed in rats killed 30 min apart, the difference in the amount of soluble 40Ca was much higher in the rats fed on the basal diet containing 200 g casein/kg than in other groups.3. This specific effect on Ca absorption, particularly in the distal portion of the small intestine, could be seen also after 45Ca was directly injected into ligated segments in situ. The amount of 45Ca in the portal blood 15 min after injection of the label was also highest in the rats given the basal diet.4. The results were in agreement with our previous findings that the formation and accumulation of casein phosphopeptides causes an increase in the amount of soluble Ca in the distal small intestine.


1988 ◽  
Vol 89 (2) ◽  
pp. 197-201 ◽  
Author(s):  
Camille F. Nassar ◽  
Eric W. Khairallah ◽  
Michel G. Nasser ◽  
Zuheir M. Habbal

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Megan Beggs ◽  
Justin Lee ◽  
Kai Busch ◽  
Ahsan Raza ◽  
Henrik Dimke ◽  
...  

Abstract Objectives Intestinal Ca2+ absorption early in life is vital to achieving optimal bone mineralization. The molecular details of intestinal Ca2+ absorption have been defined in adults, after peak bone mass has been reached, but are largely unexplored during development. We sought to delineate the molecular details of transcellular Ca2+ absorption across the small intestine which facilitate a positive calcium balance during growth. Methods We used wildtype, Cav1.3 knockout and Trpv6 mutant mice. Expression of small intestinal and renal calcium transport genes was assessed using quantitative PCR. Net transcellular 45-calcium flux across intestinal segments was measured in Ussing chambers. Femurs we analyzed using micro-CT and histology. Results Significant TRPV6 mediated Ca2+ flux across the duodenum was absent in pre-weaned (P14) mice but occurred post-weaning. In contrast, we found significant transcellular Ca2+ absorption in the jejunum and ileum at P14 but not 2 months. TRPV6 and Cav1.3 are necessary for this jejunal absorption and Cav1.3 appears to mediate absorption across the ileum although compensation is present in knockout pups. Knockout of Cav1.3 induces a compensatory increase in renal Ca2+ reabsorption in P14 mice although these pups have increased growth plate thickness suggesting delayed bone mineralization. Conclusions This work provides molecular details of how the small intestine facilitates increased demand for Ca2+ early in life to meet the requirements of growth and highlights the complexity of the multiple mechanisms involved in achieving a positive Ca2+ balance. Funding Sources This work is funded by grants from the Women and Children's Health Research Institute, supported by the Stollery Children's Hospital Foundation, and the National Sciences and Engineering Research Council to RTA, who is the Canada Research Chair in Renal Epithelial Transport Physiology. MRB is supported by a Vanier Canada Graduate Scholarship, Alberta Innovates Clinician Fellowship and an NSERC Michael Smith Foreign Study Supplement. H. Dimke is funded by the Danish Medical Research Council. Work at UdS was funded by Deutsche Forschungsgemeinschaft (DFG) by IRTG1830 (to JE, VF), Sonderforschungsbereich (SFB) 894 (to JE, PW) and SFB TRR152 (to VF).


1974 ◽  
Vol 144 (2) ◽  
pp. 339-346 ◽  
Author(s):  
J S Emtage ◽  
D E M Lawson ◽  
E Kodicek

1. The synthesis of calcium-binding protein, a protein produced in the small intestine in response to vitamin D, was investigated with a view to determining whether calcium-binding-protein production could be correlated with the stimulation of calcium absorption by vitamin D. 2. A radioimmunological assay, which can quantitatively estimate calcium-binding-protein concentrations as low as 1μg/g wet wt., was used to detect the synthesis of soluble calcium-binding protein. 3. When used on intestinal supernatants from chicks dosed with vitamin D, calcium-binding protein was not detectable at 8h but was present after 12h at a concentration of 8.6μg/g wet wt.; in agreement with this an increase in calcium absorption due to vitamin D was detected at 12h but not at 8h. 4. The synthesis of calcium-binding protein was also monitored directly by making use of the ability of the iodinated antiserum to bind specifically to nascent calcium-binding protein chains on intestinal polyribosomes; in this way calcium-binding-protein synthesis could be detected 8h after dosage with vitamin D. Further, the binding reaction indicated a near linear increase in the calcium-binding-protein-synthesizing capacity over a 16h period. 5. From the amount of calcium-binding protein present 12 and 24h after vitamin D administration it is calculated that calcium-binding-protein mRNA is produced at approx. 1mol/min per intestinal cell. 6. It is concluded that the high correlation between the initiation of calcium-binding-protein synthesis and the stimulation of calcium absorption by vitamin D strengthens the proposal that calcium-binding protein plays an important role in calcium transport.


2002 ◽  
Vol 42 (1) ◽  
pp. 25-33 ◽  
Author(s):  
Takaharu Kozakai ◽  
Norio Uozumi ◽  
Kazuo Katoh ◽  
Yoshiaki Obara

2005 ◽  
Vol 85 (1) ◽  
pp. 373-422 ◽  
Author(s):  
Joost G. J. Hoenderop ◽  
Bernd Nilius ◽  
René J. M. Bindels

Ca2+is an essential ion in all organisms, where it plays a crucial role in processes ranging from the formation and maintenance of the skeleton to the temporal and spatial regulation of neuronal function. The Ca2+balance is maintained by the concerted action of three organ systems, including the gastrointestinal tract, bone, and kidney. An adult ingests on average 1 g Ca2+daily from which 0.35 g is absorbed in the small intestine by a mechanism that is controlled primarily by the calciotropic hormones. To maintain the Ca2+balance, the kidney must excrete the same amount of Ca2+that the small intestine absorbs. This is accomplished by a combination of filtration of Ca2+across the glomeruli and subsequent reabsorption of the filtered Ca2+along the renal tubules. Bone turnover is a continuous process involving both resorption of existing bone and deposition of new bone. The above-mentioned Ca2+fluxes are stimulated by the synergistic actions of active vitamin D (1,25-dihydroxyvitamin D3) and parathyroid hormone. Until recently, the mechanism by which Ca2+enter the absorptive epithelia was unknown. A major breakthrough in completing the molecular details of these pathways was the identification of the epithelial Ca2+channel family consisting of two members: TRPV5 and TRPV6. Functional analysis indicated that these Ca2+channels constitute the rate-limiting step in Ca2+-transporting epithelia. They form the prime target for hormonal control of the active Ca2+flux from the intestinal lumen or urine space to the blood compartment. This review describes the characteristics of epithelial Ca2+transport in general and highlights in particular the distinctive features and the physiological relevance of the new epithelial Ca2+channels accumulating in a comprehensive model for epithelial Ca2+absorption.


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