Effects of sodium, 1,25-dihydroxyvitamin D3 and parathyroid hormone fragment on inorganic P absorption and Type IIb sodium-phosphate cotransporter expression in ligated duodenal loops of broilers.
Three experiments were conducted with 22-day-old Arbor Acres male broilers to study the effects of Na+, 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] and parathyroid hormone fragment [PTH (1-34)] on inorganic P absorption and Type IIb sodium-phosphate cotransporter (NaP-IIb) mRNA and protein expression levels in ligated duodenal loops. The duodenal loops were perfused with solutions (pH = 6) containing zero, 50, or 150 mmol/L of Na+ as NaCl in Exp. 1, containing zero, 30, or 300 pmol/L of 1,25-(OH)2D3 in Exp. 2, or containing zero, 65, or 650 pmol/L of PTH (1-34) in Exp. 3, respectively. Compared with the control, additions of 50 and 150 mmol/L of Na+, 30 and 300 pmol/L of 1,25-(OH)2D3, or 65 and 650 pmol/L of PTH (1-34) to the perfusates promoted (P < 0.02) the P absorption percentages and rates, respectively. Additions of the above-mentioned concentrations of Na+ or 1,25-(OH)2D3 to the perfusates increased (P < 0.003) NaP-IIb mRNA level in the duodenum of broilers, and a similar trend (P = 0.08) was observed for PTH (1-34). The Na+, 1,25-(OH)2D3, and PTH (1-34) had no effects (P > 0.15) on NaP-IIb protein level in the duodenum of broilers. The results indicate that increased P absorption due to perfusions of Na+, 1,25-(OH)2D3 or PTH (1-34) might be attributed to enhanced NaP-IIb expression in the duodenum of broilers.
Mineral Nutrition Research Division, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, P. R. China.
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Liao
Mineral Nutrition Research Division, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, P. R. China.
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Suo
Mineral Nutrition Research Division, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, P. R. China.
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Lu
Mineral Nutrition Research Division, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, P. R. China.
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Hu
Mineral Nutrition Research Division, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, P. R. China.
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Zhang
Mineral Nutrition Research Division, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, P. R. China.
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Luo
D065567:Absorption, Physiological; D000818:Animals; D030161:Avian Proteins / Q000235:genetics* / Q000378:metabolism; D002117:Calcitriol / Q000378:metabolism*; D002645:Chickens / Q000235:genetics / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004386:Duodenum / Q000378:metabolism / Q000601:surgery; D008026:Ligation / Q000662:veterinary; D008297:Male; D010281:Parathyroid Hormone / Q000378:metabolism*; D010758:Phosphorus / Q000378:metabolism*; D017553:Phosphorus Compounds / Q000378:metabolism; D011897:Random Allocation; D012964:Sodium / Q000378:metabolism*; D050611:Sodium-Phosphate Cotransporter Proteins, Type III / Q000235:genetics* / Q000378:metabolism
D030161:Avian Proteins; D010281:Parathyroid Hormone; D017553:Phosphorus Compounds; D050611:Sodium-Phosphate Cotransporter Proteins, Type III; D010758:Phosphorus; D012964:Sodium; D002117:Calcitriol
broilers; duodenal loops; phosphorus absorption; regulation factors; type IIb sodium-phosphate cotransporter