Multiple pathways for L‐methionine transport in brush‐border membrane vesicles from chicken jejunum

Soriano-García, Juan F.; Torras-Llort, Mònica; Ferrer, Ruth; Moretó, Miquel

doi:10.1111/j.1469-7793.1998.527bn.x

Cited by 34 publications

(20 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although the expression of system y ϩ in epithelial cells has often been restricted to the basolateral membrane (6,20), Thwaites et al (46) reported the participation of this transport mechanism in L-Lys transport across the apical membrane of Caco-2 cells. In addition, we have previously found a Na ϩ -independent L-Met component sensitive to NEM, a specific inhibitor of system y ϩ (11), in chicken brush-border membrane vesicles (40). Those results not only confirmed y ϩ activity in the apical membrane but also indicated the capacity of this mechanism to transport L-Met in the absence of Na ϩ .…”

Section: Discussionsupporting

confidence: 67%

“…Both isoforms are expressed in Caco-2 cells (13), but some authors report the restriction of their expression to the basolateral membrane in the intestinal epithelium (50). Nevertheless, a Na ϩ -independent transport component for neutral amino acids sensitive to BCH has been detected in the apical membrane of chicken, pig, and rabbit intestine (22,40,42). Moreover, Berger et al (1) reported that apical Na ϩ -independent L-phenylalanine uptake was mediated by systems b 0,ϩ and L in Caco-2 cells.…”

Section: Discussionmentioning

confidence: 99%

“…It is essential for mammals and has been shown to be limiting in poultry nutrition (12). Multiple transport mechanisms are involved in L-Met intestinal absorption: the Na ϩ -dependent transport systems B 0 and B 0,ϩ , the Na ϩ -independent mechanisms b 0,ϩ and L, and system y ϩ , which is specific for cationic amino acids but is also able to transport neutral amino acids, including L-Met, in the presence of Na ϩ (7,21,24,26,38,40,42,46,52). Whereas systems B 0,ϩ , b 0,ϩ , and y ϩ are used by cationic amino acids, systems B 0 and L are specific for neutral amino acids (29).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Effect of pH on l- and d-methionine uptake across the apical membrane of Caco-2 cells

Martín‐Venegas

Rodríguez-Lagunas²,

Mercier³

et al. 2009

American Journal of Physiology-Cell Physiology

Self Cite

View full text Add to dashboard Cite

The transport systems involved in intestinal methionine (Met) absorption are described as Na ϩ -dependent and Na ϩ -independent mechanisms. However, since recent studies have suggested the importance of the H ϩ gradient as a driving force for intestinal nutrient absorption, the aim of the present work was to test whether Met transport across the apical membrane of Caco-2 cells is affected by extracellular pH. The results show that Land D-Met uptake was increased by lowering extracellular pH from 7.4 to 5.5, in both the presence and absence of Na ϩ . Cis-inhibition experiments revealed that inhibition of L-Met transport by 2-aminobicyclo[2,2,1]heptane-2-carboxylic acid (BCH) or L-lysine (L-Lys) was higher at a pH of 5.5. Moreover, the BCH-insensitive component was not affected by pH, whereas the L-Lys-insensitive component was increased by lowering extracellular pH, thus suggesting the participation of system L. The contribution of another mechanism, sensitive to both BCH and L-Lys, was also considered. The inhibition obtained with taurine (Tau) was also higher at a pH of 5.5, thus suggesting the involvement of system B 0,ϩ on pH-stimulated component. As for D-Met uptake, the results showed higher inhibition with L-Lys and Tau at a pH of 5.5 and no effect on the L-Lys-or Tau-insensitive component. In conclusion, Met transport across the apical membrane of Caco-2 cells is increased by low extracellular pH as the result of the stimulation of two transport systems functionally identified with systems L and B 0,ϩ for L-Met and with system B 0,ϩ for D-Met.

show abstract

Section: Discussionsupporting

confidence: 67%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Effect of pH on l- and d-methionine uptake across the apical membrane of Caco-2 cells

Martín‐Venegas

Rodríguez-Lagunas²,

Mercier³

et al. 2009

American Journal of Physiology-Cell Physiology

Self Cite

View full text Add to dashboard Cite

show abstract

“…Whether these groups of poly(A) ϩ RNA encode the same transport protein or different proteins is unclear at this moment. Using brush border membrane vesicles as the model, Soriano-Garcia et al (7,17) reported that Met is transported in the chicken jejunum by four transport systems: system b 0,ϩ -like, y ϩ m-like, L-like, and B-like. How these four transport systems relate to the current results has yet to be determined.…”

Section: Resultsmentioning

confidence: 99%

“…For years, several models have been employed in attempts to reveal the absorption mechanisms for Met and/or HMB in chickens (1)(2)(3)(4)(5)(6)(7). These studies suggested that mechanisms of methionine absorption included Na ϩ -dependent transport, Na ϩ -independent transport and/or diffusion.…”

mentioning

confidence: 99%

Poly(A)+ RNA Encoding Proteins Capable of Transporting l-Methionine and/or dl-2-Hydroxy-4-(Methylthio) Butanoic Acid Are Present in the Intestinal Mucosa of Broilers

Pan

Wong

Dibner

et al. 2002

The Journal of Nutrition

View full text Add to dashboard Cite

To investigate the presence of poly (A) ϩ RNA that encode proteins capable of transporting Lmethionine (L-Met) and/or DL-2-hydroxy-4-(methylthio) butanoic acid (HMB), Xenopus oocytes were injected with poly(A) ϩ RNA isolated from broiler intestinal mucosa. Healthy oocytes at stage V or VI were collected from Xenopus laevis and microinjected with water, poly(A) ϩ RNA or size-fractioned poly(A) ϩ RNA. The ability of the injected oocytes to take up either L-Met or HMB was examined by incubating oocytes with [methyl-3 H]-L-Met or [5-14 C]-HMB. A greater uptake of L-Met (P Ͻ 0.01) and HMB (P Ͻ 0.05) by oocytes injected with poly(A) ϩ RNA from the duodenum, jejunum and ileum of the small intestine was observed compared with water-injected oocytes. The greatest (P Ͻ 0.05) uptake occurred when poly(A) ϩ RNA from the jejunum or ileum was injected. Injections from four different pools of sucrose gradient-fractionated poly (A) ϩ RNA from all three intestinal segments induced (P Ͻ 0.01) L-Met uptake. There were three to four different pools of sucrose gradient-fractionated poly(A) ϩ RNA from the duodenum, jejunum and ileum that induced (P Ͻ 0.05) HMB uptake. Uptake of HMB was greater at pH 5.5 than at pH 7.5 and was independent of Na ϩ . Uptake of L-Met induced by all four poly(A) ϩ RNA pools decreased dramatically when Na ϩ was removed from the uptake buffer, which indicated that the majority of L-Met uptake was Na ϩ -dependent. Methionine and DL-2-hydroxy-4-(methylthio) butanoic acid (HMB) are commonly used as supplements in diet formulation in poultry feeding because of insufficient quantities of Met in commercial feedstuffs. For years, several models have been employed in attempts to reveal the absorption mechanisms for Met and/or HMB in chickens (1-7). These studies suggested that mechanisms of methionine absorption included Na ϩ -dependent transport, Na ϩ -independent transport and/or diffusion. Mechanisms suggested for HMB absorption included Na ϩ -independent but H ϩ -dependent transport, and/or diffusion. However, because of the inherent characteristics of the models used in the studies, the actual presence of mRNA that encode proteins capable of Met or HMB uptake or the presence of specific transport proteins for these substrates in chicken intestine has not been described.The application of molecular biotechnology to nutrition research has provided tools for researchers attempting to resolve the nature of potential absorption mechanisms. One of the unique techniques that has resolved many questions related to transport proteins is expression cloning using Xenopus laevis oocytes. Xenopus oocytes are a robust system for the expression of many different proteins of animal or plant origin (8). The Xenopus oocyte is a cell specialized for the production and storage of proteins for later use during embryogenesis. Xenopus oocytes at stage V have the complete machinery to translate exogenous RNA faithfully. The most important aspect is that the oocyte expression system can make posttranslational modification...

show abstract

Morphometric study of the guinea pig small intestine during development

Mitjans

Ferrer

2004

Microscopy Res & Technique

Self Cite

View full text Add to dashboard Cite

The mucosal surface area of the guinea pig duodenum, jejunum, and ileum was determined during development, in three age groups: 1-day-old and 2- and 12-week-old animals. The morphometric analysis was performed at three magnification levels. The nominal surface area was determined at the macroscopic level, from intestinal length and perimeter. Villus and microvillus amplification factors were estimated at light-microscopic and transmission electron-microscopic levels, respectively. We found: (1) an increase in the nominal surface area that is maximal in the ileum (7.7-fold); (2) an increase in the villus amplification factor in the duodenum (1.4-fold) and a decline in the jejunum and ileum (0.8-fold), although in the jejunum villus dimensions rise; and (3) a similar increase in the microvillus amplification factor in the three segments (1.1- to 1.4-fold). In conclusion, the total mucosal surface area increased from day 1 to week 12, by 3-fold in the duodenum and jejunum and by 8-fold in the ileum. Regionally, the jejunum shows the largest mucosal surface area, followed by the ileum, and, finally, the duodenum.

show abstract

Multiple pathways for L‐methionine transport in brush‐border membrane vesicles from chicken jejunum

Cited by 34 publications

References 37 publications

Effect of pH on l- and d-methionine uptake across the apical membrane of Caco-2 cells

Effect of pH on l- and d-methionine uptake across the apical membrane of Caco-2 cells

Poly(A)+ RNA Encoding Proteins Capable of Transporting l-Methionine and/or dl-2-Hydroxy-4-(Methylthio) Butanoic Acid Are Present in the Intestinal Mucosa of Broilers

Morphometric study of the guinea pig small intestine during development

Contact Info

Product

Resources

About