Journal of Nutrition

Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Online Supporting Material
Right arrow Purchase Article
Right arrow View Shopping Cart
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Zhan, Z.
Right arrow Articles by Wang, J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Zhan, Z.
Right arrow Articles by Wang, J.
© 2008 American Society for Nutrition J. Nutr. 138:1304-1309, July 2008

Nutrient Physiology, Metabolism, and Nutrient-Nutrient Interactions

Dietary Arginine Supplementation Affects Microvascular Development in the Small Intestine of Early-Weaned Pigs1–3,

Zhenfeng Zhan4, Deyuan Ou4, Xiangshu Piao4,*, Sung Woo Kim4,5, Yanhong Liu4 and Junjun Wang4,*

4 State Key Laboratory of Animal Nutrition, China Agricultural University, Beijing, China 100094 and 5 Department of Animal Science, North Carolina State University, Raleigh, NC 27695

* To whom correspondence should be addressed. E-mail: piaoxsh{at}mafic.ac.cn or jkywjj{at}hotmail.com.


   ABSTRACT
TOP
 ABSTRACT
Introduction
 Materials and Methods
 Results
 Discussion
 LITERATURE CITED
 
This study was conducted to evaluate the effects of dietary arginine levels on microvascular development of the small intestine in early-weaned pigs. Twenty-four crossbred pigs (5.0 ± 0.3 kg body weight) were individually housed and randomly allotted to 1 of 3 diets supplemented with 0, 0.7, and 1.2% L-arginine (8 pigs per group). Pigs consumed the diets ad libitum for 10 d. We collected blood samples on d 3, 6, and 10. On d 10, 6 pigs from each group were randomly selected and killed for tissue sample collection. Compared with control pigs, dietary supplementation with 0.7% L-arginine increased (P < 0.05) jejunal concentrations of nitrite and nitrate (stable oxidation products of nitric oxide), intestinal villus height, as well as plasma proline and arginine concentrations on d 6 and 10. Dietary supplementation with 0.7% L-arginine also increased (P < 0.05) immunoreactive expression of CD34 in duodenal submucosa, ileal mucosa and submucosa, and expression of vascular endothelial growth factor (VEGF) in duodenal submucosa, jejunal mucosa and submucosa, and ileal mucosa compared with the control and 1.2% L-arginine supplementation. Dietary supplementation with 1.2% L-arginine increased (P < 0.05) the concentration of jejunal endothelin-1 compared with the control pigs. Immunoexpression of VEGF in duodenal mucosa and plasma lysine concentrations on d 6 and 10 were lower (P < 0.05) in pigs supplemented with 1.2% L-arginine than in unsupplemented pigs. Collectively, these findings indicate that the effects of L-arginine on microvascular development are beneficial at lower levels but have adverse effects at higher intakes. Dietary supplementation with 0.7% L-arginine may be a useful method to improve microvascular development in the small intestine of early-weaned pigs.


   Introduction
TOP
 ABSTRACT
 Introduction
Materials and Methods
 Results
 Discussion
 LITERATURE CITED
 
Arginine participates not only in protein synthesis but also in pyrimidine synthesis and growth hormone release. It also serves as a precursor of urea, glutamate, creatine, proline, polyamines, and nitric oxide (1–3). Arginine has been shown to be the physiological nitrogenous substrate for the production of nitric oxide and is considered an essential amino acid for young mammals, particularly under conditions of severe stress (4).

Nitric oxide produced from arginine is a major vasodilator that regulates vascular tone and hemodynamics. This free radical also plays an important role in secreting vascular endothelial growth factor (VEGF),6 modulating platelet aggregation and adhesion, maintaining endothelial function, stimulating epithelial cell migration, and inhibiting endothelin-1 release (5–8). Proline is a key component of extracellular matrix collagen that is crucial for angiogenesis and vascular remodeling (9,10). Systemic administration of L-arginine has been proposed as a safe and effective method to enhance the synthesis of nitric oxide, proline, and polyamines in animals, therefore improving wound healing and microcirculation (11–13).

Early weaning has become a widely adopted practice in the swine industry to improve herd health, growth performance of weaned pigs, and efficiency of facility utilization (14,15). However, weaning, especially early weaning, profoundly influences intestinal morphology and function of pigs. Upon weaning, the digestive system of pigs has to adapt to a dry diet instead of sow milk. As a consequence, weanling pigs often exhibit depressed feed intake and growth, reduced villus height, and increased crypt depth (16,17). In the piglet's small intestine, the microvessel is present mainly in the mucosa and submucosa (18,19). The optimal development of villi depends on an adequate supply of nutrients from both blood via intestinal microvessel and enteral feeding (20). Changes in gut morphology may result in microcirculation disorder and microvessel injury (21,22). Microvascular endothelial dysfunction may be a major factor contributing to vascular injury (23).

Endothelin-1, produced by vascular endothelial cells, is the most potent vasoconstrictor known to date (24). It may participate in the regulation of smooth muscle tone in both physiological and pathophysiological settings (25). CD34 is a specific endothelial marker, providing good contrast between microvessels and other tissue components (26,27). In addition, the VEGF is one of the most important proangiogenic factors and is able to induce angiogenesis in vivo (27,28).

Low arginine intake due to depressed feed intake may be one of the reasons for increased intestinal epithelial damage in early-weaned pigs. Therefore, we hypothesized that dietary L-arginine supplementation might prevent or alleviate intestinal atrophy and microcirculation disorder in early-weaned pigs. This study was conducted to test this hypothesis by determining concentrations of nitrite and nitrate [stable oxidation products of nitric oxide (29)] and endothelin-1, the immunoreactive expression of CD34 and VEGF, as well as plasma amino acids.


   Materials and Methods
TOP
 ABSTRACT
 Introduction
 Materials and Methods
Results
 Discussion
 LITERATURE CITED
 
    Experimental design and animal management. A basal diet (Table 1) without antibiotics was formulated to meet or exceed the nutrient recommendations of NRC (30). A large quantity of bovine dried skim milk was included to produce a diet with low arginine levels, because bovine dried skim milk has a relatively low concentration of arginine (1). Two additional diets were formulated by supplementation of the basal diet with 0.7 and 1.2% L-arginine-free base [molecular weight (MW) 174.2]. The diets were made isonitrogenous by the addition of various levels of L-alanine (MW 89.1), as described by Kim and Wu (31).


View this table:
[in this window]
[in a new window]

  		TABLE 1 Composition and nutrient levels of the basal diet (on an as-fed basis)1

 
A total of 24 Large White x Landrace piglets of 5.0 ± 0.3 kg were randomly allotted to 1 of the 3 experimental diets. In each treatment group, 6 pigs were weaned at 14 d and 2 other pigs were weaned at 13 and 15 d. Piglets were individually housed in 1.3- x 1.2-m pens with slotted stainless steel floors. The mechanically ventilated nursery room was supplied with 16 h light:8 h dark and the temperature was maintained at 25–27°C. Feed and water were consumed ad libitum. Fresh manure samples were collected daily for determination of moisture. Samples with moisture contents higher than 70% were considered to be diarrhea. The incidence of diarrhea for the piglets was calculated as [(number of piglets with diarrhea x number of days of diarrhea) / (total number of piglets x number of days of experiment)] x 100 (17). We measured body weight and feed intake of pigs at d 0 and 10. Blood samples were collected on d 3, 6, and 10 for measuring plasma amino acids. This study was approved by the China Agricultural University Animal Care and Use Committee.

    Tissue collection and processing. On d 10, 6 piglets from each group were randomly selected to be killed by a lethal intraperitoneal injection of sodium pentobarbital. Samples of duodenum (5 cm from pylorus), jejunum (middle jejunum), and ileum were acquired for histological analysis, as well as determination of endothelin-1, nitrite, nitrate, and protein contents.

    Histological analysis. For histological analysis, tissue samples were fixed in 10% neutral buffered formalin and embedded in paraffin for subsequent histological measurement according to the procedures described by Owusu-Asiedu et al. (32). Briefly, 6 cross sections were obtained from each formalin-fixed segment and processed for histological examination using the standard hematoxylin and eosin method. Villus height and crypt depth were measured according to Wu et al. (33) under a light microscope (CK-40, Olympus). Ten villus height and crypt depth measurements were taken from each section on random-selected microscopic fields. The histological analysis was performed by an investigator who was unaware of the origin of tissue sections.

    Immunohistochemistry. The primary antiserum provided a rabbit polyclonal antibody raised against the C-terminal portion of human CD34. The antibody was used to identify vascular endothelial cells in the small intestine (Supplemental Figs. 1–3). It was also employed to recognize the N-terminal end of human VEGF (BSCX-Biotech; catalogue nos. BA0532 and BA0407) as an indicator of angiogenesis (Supplemental Figs. 4–6). Slides were deparaffinized and rehydrated. A commercial Strept-Avidin-Biotin-Enzyme Complex kit (BSCX-Biotech) was used for immunohistochemistry. Briefly, sections of formalin-fixed paraffin-embedded tissues were digested with 3% H2O2 for 20 min at room temperature, incubated sequentially with 10% normal rabbit serum for 20 min after microwave antigen recovery, with CD34 (1:200) or VEGF (1:50) at 4°C overnight, and then with corresponding biotinylated secondary antibodies against rabbit and streptavidin peroxidase. Subsequently, binding of the primary antibody was detected with diaminobenzidine. Sections were counterstained with hematoxylin. In the negative control, the antibodies were substituted by PBS.

Immunochemical staining sections were photographed using a Leica DFC 320 digital camera (Leica Microsystems). The OD in tissues was integrated by computer-assisted image analysis (Image-Pro Plus; Media Cybernetics) in each 400x magnified field (34). Eight microscopic fields for each section were quantified.

    Measurements of endothelin-1 and nitric oxide metabolites. Intestinal samples were washed 3 times in ice-cold PBS to remove the mucus and digesta, frozen quickly in liquid nitrogen, and then stored at –70°C until needed for the analysis of endothelin-1, nitrite, nitrate, and protein determination. Samples of the small intestine (100 mg) were homogenized in phosphate buffer (0.2 mol/L, pH = 7.4 and 4°C containing 50 mg soybean trypsin inhibitor/L and 0.1 mmol/L phenylmethylsulfonyl fluoride). The homogenate was centrifuged at 3000 x g; 15 min and the supernatant was used for the assay.

The concentration of endothelin-1 in the small intestine was measured using a commercially available pig enzyme-linked immunosorbent assay kit EK-023–01 (Phoenix Pharmaceuticals) according to the manufacturer's instructions. The values were expressed as picogram of endothelin-1 per milligram protein in the supernatant. The concentrations of nitrite, nitrate, and total protein were quantified using assay kits (Nanjing Jiancheng Biochemistry). Briefly, nitrate was enzymatically converted into nitrite by NADPH-dependent nitrate reductase and OD was measured at 550 nm, then the nitrite molar concentrations were quantified by comparison to NaNO2 standards, and protein was quantified using Coomassie Brilliant Blue G-250.

    Plasma amino acids analysis. Amino acids in plasma were analyzed using a S-433D amino acid analyzer (SYKAM) according to the Ninhydrin postcolumn derivatization method using amino acid standards procured from Sigma.

    Statistical analysis. Difference in incidence of diarrhea among treatment groups were determined by the chi-square contingency test. All other data are means ± SEM. Statistical analyses were performed using the general linear model procedures of SAS (version 8.2, SAS Institute). Differences between means were determined using the Duncan's multiple range test. P ≤ 0.05 was considered significant.


   Results
TOP
 ABSTRACT
 Introduction
 Materials and Methods
 Results
Discussion
 LITERATURE CITED
 
    Diarrhea incidence. Although body weight, feed intake, and feed efficiency did not differ among the treatment groups (Table 2), dietary supplementation with 0.7% L-arginine reduced (P < 0.05) the incidence of diarrhea compared with the control pigs. Pigs fed diets supplemented with 1.2% L-arginine had a greater incidence of diarrhea than the other groups (P < 0.05).


View this table:
[in this window]
[in a new window]

  		TABLE 2 Effects of dietary L-arginine supplementation on growth performance and diarrhea incidence of early-weaned pigs1

 
    Small intestinal morphology. To explain why a high level of L-arginine supplementation (1.2%) caused serious diarrhea, the small intestines of the piglets were collected at the end of the experiment and the villus height and crypt depth were examined (Fig. 1). Supplementation with 0.7% L-arginine increased (P < 0.05) the villus height throughout the small intestine compared with the control and 1.2% arginine groups, which did not differ. Crypt depth was greater in the duodenum and jejunum of the control group compared with those supplemented with 0.7% L-arginine (P < 0.05). Supplementation with 0.7% L-arginine increased (P < 0.05) the villus height throughout the small intestine.


Figure 1
View larger version (26K):
[in this window]
[in a new window]

  		FIGURE 1  Effects of dietary L-arginine supplementation on morphology in the small intestine of early-weaned pigs. Bars represent the mean ± SEM, n = 6. Within an intestinal region, means without a common letter differ, P < 0.05.

 
    CD34 and VEGF immunoreactive expression. The immunoreactive expression of CD34 was examined by immunohistochemical assays and the expression of CD34 was quantified (Table 3). The expression of CD34 in piglets supplemented with 0.7% L-arginine was generally higher (P < 0.05) than the other 2 groups in the duodenal submucosa and ileum but not in the middle jejunum. The integrated OD (IOD) did not differ between the controls and the pigs receiving 1.2% L-arginine.


View this table:
[in this window]
[in a new window]

  		TABLE 3 Effects of dietary L-arginine supplementation on the immunoreactive expression of CD34 in the small intestine of early-weaned pigs12

 
We determined the immunoreactive expression of VEGF and found that relative to the control, supplementation with 0.7% L-arginine increased (P < 0.05) the IOD in the duodenal submucosa, middle jejunal mucosa and submucosa, and the ileal mucosa (Table 4). In contrast, dietary supplementation with 1.2% L-arginine reduced (P < 0.05) the expression of VEGF in the duodenal mucosa compared with control pigs (Table 4).


View this table:
[in this window]
[in a new window]

  		TABLE 4 Effects of dietary L-arginine supplementation on the immunoreactive expression of VEGF in the small intestine of early-weaned pigs12

 
    Concentrations of endothelin-1 and nitric oxide metabolites in the small intestine. Dietary supplementation with 0.7% L-arginine increased concentrations of nitrite and nitrate in the jejunum and ileum. In contrast, dietary supplementation with 1.2% L-arginine resulted in a lower level of nitric oxide metabolites in the ileum (Fig. 2A). In contrast, the endothelin-1 concentration at all 3 intestinal sites was lower in pigs supplemented with 0.7% L-arginine than with 1.2% L-arginine (P < 0.05; Fig. 2B).


Figure 2
View larger version (26K):
[in this window]
[in a new window]

  		FIGURE 2  Effects of dietary L-arginine supplementation on nitric oxide (A) and endothelin-1 (B) concentration in the small intestine of early-weaned pigs. Bars represent the mean + SEM, n = 6. Within an intestinal region, means without a common letter differ, P < 0.05.

 
    Plasma amino acids. The plasma concentrations of amino acids were determined on d 3, 6, and 10 after weaning (Table 5). No amino acid differed among the 3 groups of pigs on d 3, whereas dietary supplementation with 0.7% L-arginine increased (P < 0.05) plasma concentrations of proline and L-arginine on d 6 and 10 and of citrulline on d 10 compared with control pigs. Supplementation with 1.2% L-arginine decreased (P < 0.05) lysine concentration in plasma on d 6 and 10 compared with the other 2 groups of pigs.


View this table:
[in this window]
[in a new window]

  		TABLE 5 Effects of dietary L-arginine supplementation on plasma concentrations of amino acids in early-weaned pigs1

 

   Discussion
TOP
 ABSTRACT
 Introduction
 Materials and Methods
 Results
 Discussion
LITERATURE CITED
 
CD34 is an endothelial marker whose expression level reflects the condition of angiogenesis and can be used to determine vascular density (26). Angiogenesis is necessary for the growth of blood vessels in response to a variety of physiological and pathological conditions (28). VEGF is a key regulator of endothelial cell proliferation and angiogenesis (27,35). Results of this study indicated that dietary supplementation with 0.7% L-arginine had a positive effect on villus height (Fig. 1A) and enhanced the expression of VEGF and CD34 (Tables 3 and 4). Notably, intestinal villus height decreased and the incidence of diarrhea increased in the control pigs and pigs supplemented with 1.2% L-arginine. Villus atrophy and crypt hyperplasia were associated with reduced expression of CD34 and VEGF. The findings suggest that dietary supplementation with 0.7% arginine improved the development of the vascular endothelium in early-weaned pigs.

The intestinal concentration of endothelin-1 increased markedly in pigs of 1.2% arginine supplementation compared with 0.7% supplementation. Because endothelin-1 acts as a promoter of leukocyte rolling in the vessel (25), it may have adverse effects on intestinal microcirculation. If not balanced by concomitant vasodilatory stimuli, endogenous endothelin-1 may contribute to ischemia/reperfusion injury in the gut (36). The repair of such endothelial damage is crucial for the maintenance of structure and function of the injured vessels.

Dietary L-arginine supplementation may contribute to the repair of injured vasculature through nitric oxide- and polyamine-mediated mechanisms (5). Nitric oxide can downregulate endothelin-1 production and endothelin-1 can participate in the regulation of nitric oxide generation by acting on the endothelium (37). In the present experiment, this balance shifted in the control pigs and the pigs supplemented with 1.2% arginine. Concentrations of endothelin-1 increased rapidly under stress, which required an increased amount of nitric oxide to maintain the balance. However, the availability of nitric oxide was reduced in these 2 groups of pigs compared with pigs supplemented with 0.7% arginine (Fig. 1). Thus, an appropriate level of dietary arginine may be effective in maintaining a healthy balance between nitric oxide and endothelin-1 in the small intestine. The daily arginine requirement for 2- to 3-wk-old pigs is suggested as 1.48 g (30). However, recent studies demonstrated that 2- to 3-wk-old pigs have higher arginine requirements than the NRC recommendation (1,31). In our experiment, 0.7 and 1.2% arginine supplementation allowed 58 and 95% higher daily arginine intakes than NRC recommendations, respectively (Table 2).

As reported by other investigators (3), dietary supplementation with 0.7 and 1.2% L-arginine increased plasma concentrations of L-arginine in weanling pigs compared with the control on d 6 and 10 (Table 5). Because arginine and lysine share the same transport systems, a change in dietary arginine:lysine ratios may affect the intestinal absorption of these 2 amino acids (1). In support of this view, we found that plasma lysine levels were reduced substantially in pigs supplemented with 1.2% L-arginine (Table 5). Despite much research on lysine-arginine antagonism in rats, little is known about such a relationship in porcine enterocytes (38,39). Excess lysine appeared to reduce growth via amino acid imbalance rather than antagonism with arginine, although the circulating level of arginine was lowered (40). When piglets are deficient in lysine, utilization of dietary amino acids for tissue protein synthesis is impaired (38), leading to their excess oxidation and possibly generation of reactive oxygen species (41). The reaction of nitric oxide with superoxide anion forms the powerful oxidant peroxynitrite, eventually causing production of hydroxyl radical and exacerbating oxidative injury (42). Thus, amino acid imbalance may exacerbate stress of pigs and ultimately lead to increased endothelin-1 concentration. Pigs fed diets supplemented with 1.2% L-arginine had a greater incidence of diarrhea, which may due to the increased endothelin-1 concentration in the small intestine (43).

Circulating citrulline is derived from intestinal synthesis from glutamine and proline, as well as nitric oxide synthase in various cell types (2). All of these pathways may contribute to greater plasma concentrations of citrulline in piglets supplemented with 0.7% L-arginine on d 10 postweaning compared with the control (Table 5). Dietary supplementation with L-arginine may increase the synthesis of polyamines and proline via arginase (44), as well as collagen (45), in wounded tissues. This is consistent with the finding that plasma levels of proline were greater in piglets supplemented with 0.7% arginine than in control pigs on d 6 and 10 postweaning (Table 5). Proline can ameliorate arginine deficiency in pigs (46). Meanwhile, proline and arginine are major substrates for polyamine synthesis in enterocytes of piglets (44,47). This pathway is expected to be suboptimal when there is inadequate provision of these 2 amino acids (39). Moreover, as a key element of collagen, a decrease in proline availability may be responsible for the reduced expression of CD34 and VEGF in the small intestine.

In conclusion, these findings indicate that the effects of L-arginine on microvascular development of early-weaned pigs were beneficial at lower levels but had adverse effects at higher intakes. Dietary supplementation with 0.7% L-arginine enhanced expression of angiogenic factors in the small intestine of weanling piglets. However, excessive supplementation with L-arginine (1.2%) aggravated weaning stress and intestinal dysfunction. Adequate L-arginine provision may be a novel and effective means to ameliorating microvessel injury and improving absorption of nutrients in the small intestine.


   FOOTNOTES
 
1 Supported by the National Basic Research Program of China (2004 CB 117503), Natural Science Foundation of China (U0731001 and 30600434), and the Ministry of Science and Technology of the People's Republic of China (2006 BAD12B05-10; Nyhyzx07-034). Back

2 Author disclosures: Z. Zhan, D. Ou, X. Piao, S. Kim, Y. Liu, and J. Wang, no conflicts of interest. Back

3 Supplemental Figures 1–6 are available with the online posting of this paper at jn.nutrition.org. Back

6 Abbreviations used: IOD, integrated OD; MW, molecular weight; VEGF, vascular endothelial growth factor. Back

Manuscript received 15 January 2008. Initial review completed 29 January 2008. Revision accepted 24 April 2008.


   LITERATURE CITED
TOP
 ABSTRACT
 Introduction
 Materials and Methods
 Results
 Discussion
 LITERATURE CITED
 

1. Wu G, Knabe DA, Kim SW. Arginine nutrition in neonatal pigs. J Nutr. 2004;134:S2783–90.[Abstract/Free Full Text]

2. Wu G, Morris SM Jr. Arginine metabolism: nitric oxide and beyond. Biochem J. 1998;336:1–17.[Medline]

3. Morris SM Jr. Enzymes of arginine metabolism. J Nutr. 2004;134:S2743–7.[Abstract/Free Full Text]

4. Wakabayashi Y, Yamada E, Yoshida T, Takahashi H. Arginine becomes an essential amino acid after massive resection of rat small intestine. J Biol Chem. 1994;269:32667–71.[Abstract/Free Full Text]

5. Wu G, Meininger CJ. Arginine nutrition and cardiovascular function. J Nutr. 2000;130:2626–9.[Abstract/Free Full Text]

6. Rhoads JM, Chen W, Gookin J, Wu GY, Fu Q, Blikslager AT, Rippe RA, Argenzio RA, Cance WG, et al. Arginine stimulates intestinal cell migration through a focal adhesion kinase dependent mechanism. Gut. 2004;53:514–22.[Abstract/Free Full Text]

7. Ziche M, Morbidelli L, Choudhuri R, Zhang HT, Donnini S, Granger HJ, Bicknell R. Nitric oxide synthase lies downstream from vascular endothelial growth factor-induced but not basic fibroblast growth factor-induced angiogenesis. J Clin Invest. 1997;99:2625–34.[Medline]

8. Lee PC, Salyapongse AN, Bragdon GA, Shears LL, Watkins SC, Edington HDJ, Billiar TR. Impaired wound healing and angiogenesis in eNOS-deficient mice. Am J Physiol Heart Circ Physiol. 1999;277:1600–8.

9. Mussini E, Hutton JJ Jr, Udenfriend S. Collagen proline hydroxylase in wound healing, granuloma formation, scurvy, and growth. Science. 1967;1967:927–9.

10. Adams E, Frank L. Metabolism of proline and the hydroxyprolines. Annu Rev Biochem. 1980;49:1005–61.[Medline]

11. Wu G, Meininger CJ. Regulation of nitric oxide synthesis by dietary factors. Annu Rev Nutr. 2002;22:61–86.[Medline]

12. Wu G, Bazer FW, Cudd TA, Jobgen WS, Kim SW, Lassala A, Li P, Matis JH, Meininger CJ, et al. Pharmacokinetics and safety of arginine supplementation in animals. J Nutr. 2007;137:S1673–80.[Abstract/Free Full Text]

13. Barbul A, Lazarou SA, Efron DT, Wasserkrug HL, Efron G. Arginine enhances wound healing and lymphocyte immune responses in humans. Surgery. 1990;108:331–6.[Medline]

14. Dial GD, Wiseman BS, Davies PR, Marsh WE, Molitor TW, Morrison RB, Thawley DG. Strategies employed in the United States for improving the health of swine. Pig News Info. 1992;13:111–23.

15. Tang M, Laarveld B, Van Kessel AG, Hamilton DL, Estrada A, Patience JF. Effect of segregated early weaning on postweaning small intestinal development in pigs. J Anim Sci. 1999;77:3191–200.[Abstract/Free Full Text]

16. Kelly D, Smyth JA, McCracken KJ. Digestive development of the early-weaned pig. 1. Effect of continuous nutrient supply on the development of the digestive tract and on changes in digestive enzyme activity during the first week post-weaning. Br J Nutr. 1991;65:169–80.[Medline]

17. Ou DY, Li DF, Cao YH, Li XL, Yin JD, Qiao SY, Wu G. Dietary supplementation with zinc oxide decreases expression of the stem cell factor in the small intestine of weanling pigs. J Nutr Biochem. 2007;18:820–6.[Medline]

18. Gore RW, Bohlen HG. Microvascular pressures in rat intestinal muscle and mucosal villi. Am J Physiol Heart Circ Physiol. 1977;233:685–93.

19. Sieber C, Beglinger C, Jaeger K, Hildebrand P, Stalder GA. Regulation of postprandial mesenteric blood flow in humans: evidence for a cholinergic nervous reflex. Gut. 1991;32:361–6.[Abstract/Free Full Text]

20. Matheson PJ, Wilson MA, Garrison RN. Regulation of intestinal blood flow. J Surg Res. 2000;93:182–96.[Medline]

21. Kalia N, Pockley AG, Wood RFM, Brown NJ. Effects of FK409 on intestinal ischemia-reperfusion injury and ischemia-induced changes in the rat mucosal villus microcirculation. Transplantation. 2001;72:1875–80.[Medline]

22. Nakajima Y, Baudry N, Duranteau J, Vicaut E. Microcirculation in intestinal villi: a comparison between hemorrhagic and endotoxin shock. Am J Respir Crit Care Med. 2001;164:1526–30.[Abstract/Free Full Text]

23. Granger DN, Kubes P. The microcirculation and inflammation: modulation of leukocyte-endothelial cell adhesion. J Leukoc Biol. 1994;55:662–75.[Abstract]

24. Yanagisawa M, Kurihara H, Kimura S, Tomobe Y, Kobayashi M, Mitsui Y, Yazaki Y, Goto K, Masaki T. A novel potent vasoconstrictor peptide produced by vascular endothelial cells. Nature. 1988;332:411–5.[Medline]

25. Boros M, Massberg S, Baranyi L, Okada H, Messmer K. Endothelin 1 induces leukocyte adhesion in submucosal venules of the rat small intestine. Gastroenterology. 1998;114:103–14.[Medline]

26. Weidner N. Intratumor microvessel density as a prognostic factor in cancer. Am J Pathol. 1995;147:9–19.[Medline]

27. Meininger CJ, Wu G. Regulation of endothelial cell proliferation by nitric oxide. Methods Enzymol. 2002;352:280–95.[Medline]

28. Leung DW, Cachianes G, Kuang WJ, Goeddel DV, Ferrara N. VEGF is a secreted angiogenic mitogen. Science. 1989;246:1306–9.[Abstract/Free Full Text]

29. Jobgen WS, Jobgen SC, Li H, Meininger CJ, Wu G. Analysis of nitrite and nitrate in biological samples using high-performance liquid chromatography. J Chromatogr B Analyt Technol Biomed Life Sci. 2007;851:71–82.[Medline]

30. NRC. Nutrient requirements of swine. 10th ed. Washington, DC: National Academic Press; 1998.

31. Kim SW, Wu G. Dietary arginine supplementation enhances the growth of milk-fed young pigs. J Nutr. 2004;134:625–30.[Abstract/Free Full Text]

32. Owusu-Asiedu A, Nyachoti CM, Marquardt RR. Response of early-weaned pigs to an enterotoxigenic Escherichia coli (K88) challenge when fed diets containing spray-dried porcine plasma or pea protein isolate plus egg yolk antibody, zinc oxide, fumaric acid, or antibiotic. J Anim Sci. 2003;81:1790–8.[Abstract/Free Full Text]

33. Wu G, Meier SA, Knabe DA. Dietary glutamine supplementation prevents jejunal atrophy in weaned pigs. J Nutr. 1996;126:2578–84.[Abstract/Free Full Text]

34. Zhou X, Li D, Yin J, Ni J, Dong B, Zhang J, Du M. CLA differently regulates adipogenesis in stromal vascular cells from porcine subcutaneous adipose and skeletal muscle. J Lipid Res. 2007;48:1701–9.[Abstract/Free Full Text]

35. Cao R, Eriksson A, Kubo H, Alitalo K, Cao Y, Thyberg J. Comparative evaluation of FGF-2-, VEGF-A-, and VEGF-C-induced angiogenesis, lymphangiogenesis, vascular fenestrations, and permeability. Circ Res. 2004;94:664–70.[Abstract/Free Full Text]

36. Han H, Neubauer S, Braeker B, Ertl G. Endothelin-1 contributes to ischemia/reperfusion injury in isolated rat heart: attenuation of ischemic injury by the endothelin-1 antagonists BQ123 and BQ610. J Mol Cell Cardiol. 1995;27:761–6.[Medline]

37. Warner TD. Relationships between the endothelin and nitric oxide pathways. Clin Exp Pharmacol Physiol. 1999;26:247–52.[Medline]

38. Baker DH. Lysine, arginine, and related amino acids: an introduction to the 6th amino acid assessment workshop 1–3. J Nutr. 2007;137:1599S–1601.[Abstract/Free Full Text]

39. Wu G. Intestinal mucosal amino acid catabolism. J Nutr. 1998;128:1249–52.[Abstract/Free Full Text]

40. Edmonds MS, Baker DH. Failure of excess dietary lysine to antagonize arginine in young pigs. J Nutr. 1987;117:1396–401.[Abstract/Free Full Text]

41. Wu G, Fang YZ, Yang S, Lupton JR, Turner ND. Glutathione metabolism and its implications for health. J Nutr. 2004;134:489–92.[Abstract/Free Full Text]

42. Brunini TMC, Mendes-Ribeiro AC, Ellory JC, Mann GE. Platelet nitric oxide synthesis in uremia and malnutrition: a role for L-arginine supplementation in vascular protection. Cardiovasc Res. 2007;73:359–67.[Abstract/Free Full Text]

43. Maurer M, Wedemeyer J, Metz M, Piliponsky AM, Weller K, Chatterjea D, Clouthier DE, Yanagisawa MM, Tsai M, et al. Mast cells promote homeostasis by limiting endothelin-1-induced toxicity. Nature. 2004;432:512–6.[Medline]

44. Wu G, Flynn NE, Knabe DA. Enhanced intestinal synthesis of polyamines from proline in cortisol-treated piglets. Am J Physiol Endocrinol Metab. 2000;279:E395–402.[Abstract/Free Full Text]

45. Albina JE, Mills CD, Barbul A, Thirkill CE, Henry WL, Mastrofrancesco B, Caldwell MD. Arginine metabolism in wounds. Am J Physiol Endocrinol Metab. 1988;254:E459–67.[Abstract/Free Full Text]

46. Brunton JA, Bertolo RFP, Pencharz PB, Ball RO. Proline ameliorates arginine deficiency during enteral but not parenteral feeding in neonatal piglets. Am J Physiol Endocrinol Metab. 1999;277:223–31.

47. Wu G. Synthesis of citrulline and arginine from proline in enterocytes of postnatal pigs. Am J Physiol Gastrointest Liver Physiol. 1997;272:G1382–90.[Abstract/Free Full Text]





This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Online Supporting Material
Right arrow Purchase Article
Right arrow View Shopping Cart
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Zhan, Z.
Right arrow Articles by Wang, J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Zhan, Z.
Right arrow Articles by Wang, J.

Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Copyright © 2008 by American Society for Nutrition