Vitamin D_(3)(VD_(3)),an essential nutrient for animals,has been demonstrated to stimulate the uptake of certain amino acids.However,the role of VD_(3) in the intestine,the primary site for digestion and absorption of...Vitamin D_(3)(VD_(3)),an essential nutrient for animals,has been demonstrated to stimulate the uptake of certain amino acids.However,the role of VD_(3) in the intestine,the primary site for digestion and absorption of nutrients,remains poorly characterized.Here,the grass carp(Ctenopharyngodon idella)was studied to assess the influence of different doses of VD_(3)(15.2,364.3,782.5,1,167.9,1,573.8,and 1,980.1 IU/kg)on growth performance,intestinal morphology,digestive absorption,amino acid transport,and potential signaling molecule levels in a feeding experiment.As a result,dietary VD_(3) improved growth performance,intestinal structure,and digestive and brush border enzyme activities.Additionally,most intestinal free amino acids and their transporters were upregulated after VD_(3) intake,except for Ala,Lys,Asp,Leu,solute carrier(SLC)7A7,SLC1A5,and SLC1A3 mRNA in different segments,Leu and SLC6A14 mRNA in the proximal intestine,and SLC7A5 mRNA in the mid and distal intestine.In the crucial target of rapamycin(TOR)signal pathway of amino acid transport,the gene and protein expression of TOR,S6 kinase 1,and activating transcription factor 4 were elevated,whereas 4E-binding protein 1 was decreased,further suggesting an advanced amino acid absorption capacity in the fish due to VD_(3) supplementation.Based on percentage weight gain,feed efficiency,and trypsin activity,the VD_(3) requirements of on-growing grass carp were estimated to be 968.33,1,005.00,and 1,166.67 IU/kg,respectively.Our findings provide novel recommendations for VD_(3) supplementation to promote digestion and absorption capacities of fish,contributing to the overall productivity of aquaculture.展开更多
Ten outbred pigs were each operated on for three times. First, a 130 cm length of terminal ileum of each pig was isolated on its vascular pedicle as a Thiry-Vella loop. One week later, the solitary ileal segments were...Ten outbred pigs were each operated on for three times. First, a 130 cm length of terminal ileum of each pig was isolated on its vascular pedicle as a Thiry-Vella loop. One week later, the solitary ileal segments were transplanted heterotopically in two pigs. And after 28 days of heterotopic transplantation, the transplanted intestine was interposed into continuity of host intestine as orthotopic transplant. During the experiment, tests were made on 6th day after the first operation (period 1), the 14th (II), 28th (III) day after heterotopic transplantation, and 3 weeks after interposition (IV) respectively for the levels of glucose, palmitate and leucine. Additionally, at period I, III, and IV, a 3 cm length of intestinal mucosa was excised for morphologic observation and determination of DNA, RNA and protein contents. After heterotopic transplantation, the absorptive function of transplanted intestine was severely impaired for two weeks. The absorption of glucose! and palmitate was partially recovered by period III, at which time leucine level had return to normal. At period IV, the absorptive function of glucose and leucine had surpassed normal levels, while palmitate had risen to the level of pretransplantation. After transplantation, at period III, DNA, RNA and protein contents were well below normal. Three weeks after orthotopic transplantation, RNA and protein had risen to normal level, while DNA content remained below normal, The morphologic changes during the experiment were correlated with the changes of contents in RNA, protein and DNA. The area, height, width of villi and the area, depth, width:of crypt were below normal at III and recovered by 3 weeks after orthotopic transplantation (period IV), but were still lower than the levels at pretransplantation. Crypt depths were deeper than those of pretransplantation.展开更多
基金National Key R&D Program of China(2019YFD0900200,2018YFD0900400)National Natural Science Foundation of China for Outstanding Youth Science Foundation(31922086)+1 种基金Young Top-Notch Talent Support Program,China Agriculture Research System of MOF and MARA(CARS-45)Sichuan Science and Technology Program(2019YFN0036).
文摘Vitamin D_(3)(VD_(3)),an essential nutrient for animals,has been demonstrated to stimulate the uptake of certain amino acids.However,the role of VD_(3) in the intestine,the primary site for digestion and absorption of nutrients,remains poorly characterized.Here,the grass carp(Ctenopharyngodon idella)was studied to assess the influence of different doses of VD_(3)(15.2,364.3,782.5,1,167.9,1,573.8,and 1,980.1 IU/kg)on growth performance,intestinal morphology,digestive absorption,amino acid transport,and potential signaling molecule levels in a feeding experiment.As a result,dietary VD_(3) improved growth performance,intestinal structure,and digestive and brush border enzyme activities.Additionally,most intestinal free amino acids and their transporters were upregulated after VD_(3) intake,except for Ala,Lys,Asp,Leu,solute carrier(SLC)7A7,SLC1A5,and SLC1A3 mRNA in different segments,Leu and SLC6A14 mRNA in the proximal intestine,and SLC7A5 mRNA in the mid and distal intestine.In the crucial target of rapamycin(TOR)signal pathway of amino acid transport,the gene and protein expression of TOR,S6 kinase 1,and activating transcription factor 4 were elevated,whereas 4E-binding protein 1 was decreased,further suggesting an advanced amino acid absorption capacity in the fish due to VD_(3) supplementation.Based on percentage weight gain,feed efficiency,and trypsin activity,the VD_(3) requirements of on-growing grass carp were estimated to be 968.33,1,005.00,and 1,166.67 IU/kg,respectively.Our findings provide novel recommendations for VD_(3) supplementation to promote digestion and absorption capacities of fish,contributing to the overall productivity of aquaculture.
文摘Ten outbred pigs were each operated on for three times. First, a 130 cm length of terminal ileum of each pig was isolated on its vascular pedicle as a Thiry-Vella loop. One week later, the solitary ileal segments were transplanted heterotopically in two pigs. And after 28 days of heterotopic transplantation, the transplanted intestine was interposed into continuity of host intestine as orthotopic transplant. During the experiment, tests were made on 6th day after the first operation (period 1), the 14th (II), 28th (III) day after heterotopic transplantation, and 3 weeks after interposition (IV) respectively for the levels of glucose, palmitate and leucine. Additionally, at period I, III, and IV, a 3 cm length of intestinal mucosa was excised for morphologic observation and determination of DNA, RNA and protein contents. After heterotopic transplantation, the absorptive function of transplanted intestine was severely impaired for two weeks. The absorption of glucose! and palmitate was partially recovered by period III, at which time leucine level had return to normal. At period IV, the absorptive function of glucose and leucine had surpassed normal levels, while palmitate had risen to the level of pretransplantation. After transplantation, at period III, DNA, RNA and protein contents were well below normal. Three weeks after orthotopic transplantation, RNA and protein had risen to normal level, while DNA content remained below normal, The morphologic changes during the experiment were correlated with the changes of contents in RNA, protein and DNA. The area, height, width of villi and the area, depth, width:of crypt were below normal at III and recovered by 3 weeks after orthotopic transplantation (period IV), but were still lower than the levels at pretransplantation. Crypt depths were deeper than those of pretransplantation.
