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Nutrient Physiology, Metabolism, and Nutrient-Nutrient Interactions

Carnosine Concentration of Ingested Meat Affects Carnosine Net Release into the Portal Vein of Minipigs¹

² UMR1019 Unité de Nutrition Humaine, and ³ Unité de Recherches sur les Herbivores, and ⁴ Qualité des Produits Animaux, Institut National de la Recherche Agronomique, Centre de Clermont-Ferrand-Theix, 63122 Saint Genès Champanelle, France and ⁵ ADIV, 63039 Clermont-Ferrand, France

^* To whom correspondence should be addressed. E-mail: remond{at}clermont.inra.fr.

	ABSTRACT

TOP ABSTRACT Introduction Materials and Methods Results Discussion LITERATURE CITED

 
Because of its physiological effects, carnosine (ß-alanyl-L-histidine) can be considered as a bioactive food component. The objective of this study was to assess the quantitative significance of intact carnosine absorption after ingestion of different beef meats, using the minipig as animal model. In a preliminary experiment, we evaluated the level of dietary carnosine in intestinal digesta of pigs (n = 4) after a meat meal (0.94 g protein/kg body weight) of grilled top loin (TL) or stewed shoulder (S). In accordance with meat carnosine concentration (20.7 and 7.2 µmol/g for TL and S, respectively), intestinal carnosine concentration was greater for TL than S. For both meats, carnosine flow to mid-jejunum was almost completed in the first 3 h following intake, and about one-half of the ingested carnosine disappeared from the intestinal lumen before the mid-jejunum. In catheterized minipigs (n = 4), we assessed the portal net release of dietary carnosine after a meat meal (1.4 g protein/kg body weight) of TL, S, and a blend of grilled neck and brisket (NB; 12.2 µmol carnosine/g). Postprandial carnosine plasma concentration and portal net release were not affected after an S meal, but they increased, proportionally to meat carnosine content, with NB and TL. For these meats, carnosine net release throughout the whole postprandial period accounted for 22% of the ingested carnosine. These results indicated that meat carnosine can be absorbed across the intestinal wall and that carnosine bioavailability depends on carnosine content of cooked meat.

	Introduction

TOP ABSTRACT Introduction Materials and Methods Results Discussion LITERATURE CITED

Carnosine is exclusively found in animal tissues, and meat is the main contributor of carnosine supply in humans. Carnosine concentration increased in human plasma after the consumption of beef (7); however, it is not known how much carnosine is actually absorbed intact across the intestinal epithelium and how absorption is affected by the type of ingested meat. The paracellular route is not dominant for carnosine absorption (5). Thus, for intact absorption, carnosine has to cross the brush border membrane of the enterocyte to remain intact within the cell and to cross the basolateral membrane. Carnosine is thought to be transported across the brush border membrane via the peptide transporter PEPT1 (8). Less is known about its outflow through the basolateral membrane. As suggested for small peptides, carnosine may reach the blood stream via a transporter less sensitive to extracellular pH than PEPT1, with lower substrate affinity but similar substrate specificity (9). Although carnosinase (EC 3.4.13.3) is less abundant than in kidney and liver, its presence has been evidenced in small intestine (10) and part of the absorbed carnosine can be hydrolyzed within the enterocyte.

In this study, we investigated the quantitative importance of carnosine release in the portal vein after ingestion of different, traditionally cooked beef meats, using the minipig as animal model. In a preliminary study, we checked the occurrence of carnosine in intestinal digesta of pigs after a meat meal.

	Materials and Methods

TOP ABSTRACT Introduction Materials and Methods Results Discussion LITERATURE CITED

 
Meats

Top loin, shoulder, neck, and brisket were taken from a Charolais cow. Meat pieces were sampled 2 d postmortem at the slaughterhouse and were matured 10 d under vacuum at 4°C. Top loin, neck, and brisket were then sliced (2 cm thickness) and grilled at 380–420°C until they reached a core temperature of 55 ± 5°C. Meats were then cooled to 4°C and cut up. Shoulder was diced (3 cm x 3 cm) and braised for 10 min with margarine (30 g/kg) before stewing in water for 135 min at 80°C. All meats were vacuum-packed and stored at –20°C prior to utilization. Before use, meats were thawed at 4°C for 16 h. The proximate composition of meats is given in Table 1.

Surgical procedures and postsurgical care were conducted according to the guidelines formulated by the European Community for the use of experimental animals (L358-86/609/EEc).

    Experiment 1. Three weeks before the experiment, 4 3-mo-old female Large White x Danish Landrace pigs (40.5 ± 5.2 kg) were surgically fitted with a T-shaped cannula (silicone rubber; 12-mm i.d., 17-mm o.d.) in the mid-jejunum (4 m downstream of the pylorus) and a catheter (polyvinyl chloride; 1.1-mm i.d., 1.9-mm o.d.) in the vena cava.

    Experiment 2. Three weeks before the experiment, 4 6-mo-old (21.3 ± 0.5 kg) female Pitman-Moore minipigs (CEGAV) were surgically fitted with catheters (polyvinyl chloride; 1.1-mm i.d., 1.9-mm o.d.) in the portal vein and the abdominal aorta and with a transit-time ultrasonic blood flow probe (12 mm A-series; Transonic Systems) around the portal vein (11). The portal vein catheter was placed via the splenic vein, with the catheter tip positioned in the liver hilus. Minipigs wore a canvas harness to protect catheters and probe connectors.

Throughout both experiments, pigs were housed in individual pens (1 x 1.5 m) separated by Plexiglas walls in a ventilated room with controlled temperature (20–23°C). They were fed twice daily in equal amounts at 0800 and 1600 with a commercial diet [18% protein (N·6.25), 2% fat, 5% cellulose, 6% ash] (Porcyprima, SANDERS) and had free access to water. At the end of the experiments, pigs were killed with an i.v. injection of sodium pentobarbital (125 mg/kg body weight) (Doléthal; Vetoquinol).

Experimental procedures

    Experiment 1. The experimental protocol included 3 periods. In the first period, all pigs received a control meal, and in the 2 other periods, grilled top loin (TL)⁶ and stewed shoulder (S) were tested according to a 2 x 2 crossover design. For each pig, sampling sessions were separated by 7 d. Pigs were food-deprived from 1630 on the day prior to sampling. At 0900 on the sampling day, they were offered a test meal exclusively composed of meat or the control meal. Each test meal provided 40 g of protein. The control meal, without carnosine, was made up of 47% free amino acid mixture, 23% wheat starch, 12% fat, and 18% water. The amino acid mixture was representative of beef meat amino acid pattern. Ytterbium (Yb)-acetate, used as a transit marker, was incorporated (as a powder) in a fraction (10%) of each test meal at a level of 1.2 mg Yb/g meal dry matter (DM). Digesta were continuously collected from 0800 to 1500 in cold plastic bottles that were replaced each hour. On sampling days, water intake was restricted to 250 mL/h. To prevent dehydration, 1 L Ringer-lactate solution was intravenously infused throughout the sampling session at a rate of 150 mL/h.

Hourly collected digesta were immediately homogenized using a Waring blender at high speed (2x 5 s spaced by 5 s). Homogenate was subsampled: 10 g was used for DM determination, 200 g was lyophilized for Yb determination, and 100 g was treated with perchloric acid (170 mmol/L, final concentration). After vigorous shaking, samples to which perchloric acid had been added were kept on ice 15 min and then centrifuged at 10,000 x g; 20 min at 4°C. Fractions of supernatants (2% of hourly collected digesta) from the postprandial period were pooled to yield 2 samples per pig: a first pool representative of the first 3 h (PP1) and a second representative of the last 3 h (PP2). Postabsorptive (PA), PP1, and PP2 supernatants were filtered through a 5000-Da cut-off filter (Vivaspin 15, VIVASCIENCE) at 2000 x g; 8 to 15 h at 4°C. Filtrates were stored at –20°C prior to analysis.

    Experiment 2. The 4 catheterized minipigs randomly received 3 test meals exclusively composed of TL, S, or a mixture of grilled neck and brisket (NB; 40/60; blend used in hamburger). At least 2 d separated sampling sessions. Before sampling, minipigs were deprived of food from 1700 to 1100 of the following day. Baseline arterial and portal blood samples were simultaneously withdrawn at 1000, 1030, and 1100 during the PA period. Then, at 1105, minipigs were offered a test meal (30 g protein per meal). Arterial and portal blood samples were then taken at 1130, 1200, 1300, 1400, 1500, 1630, and 1800. Blood samples (5 mL) were collected in cold syringes with lithium heparin as anticoagulant (S-monovettes, Starstedt). Portal vein blood flow was continuously recorded during the sampling session.

Hemoglobin concentration, pH, bicarbonate ion concentration, and packed cell volume (PCV) were immediately determined using an automatic blood-gas analyzer (ABL510, Radiometer). The remaining blood was centrifuged at 3000 x g; 10 min at 4°C. Plasma (300 µL) spiked with homocarnosine as internal standard (30 µL, 10 µmol/L) was vortexed with sulfosalicylic acid (190 mmol/L, final concentration) for 1 min, then left 15 min at room temperature and centrifuged at 10,000 x g; 15 min at 4°C. The resulting supernatant was stored at –80°C.

Analytical methods

Lyophilized postprandial digesta were pooled at 10% DM of hourly collected digesta and homogenized with a mixer. Concentration of Yb in these pools was determined using absorption spectrometry.

Carnosine content in cooked meat was determined by ion-exchange chromatography on an HPLC System (BioTek Kontron) using postcolumn derivatization with ninhydrin. Moisture, protein (Kjeldahl method), and crude fat (ether extract) were analyzed according to the methods of the AOAC (12).

Carnosine concentration in digesta and plasma was quantified by Reversed-phase-HPLC on a 5-µm C18-HDO Uptisphere (Interchim) column (250 x 4.6 mm) using a precolumn derivatization with O-phthaldehyde reagent adapted from the method of Maynard et al. (13).

Total antioxidant capacity (TAC) of plasma was measured with the iron/metmyoglobin absorption method (Randox Laboratories). Data are expressed as µmol/L Trolox equivalents.

Calculations

Yb jejunal recovery (percent of intake) was calculated as:

where [Yb] is the concentration of Yb in pooled digesta, DM is the amount collected during the whole postprandial period, and Yb_ing is the amount of ingested Yb.

Carnosine jejunal flux (mg/6 h) was calculated as:

where (Carn_jej)_PP1, (Carn_jej)_PP2 are carnosine concentrations in PP1 and PP2 digesta pool, respectively, and FM_PP1 and FM_PP2 are amounts of digesta fresh matter collected during the PP1 and PP2 periods.

The portal net flux of carnosine in plasma (PNF_carn, µmol/h) was calculated as follows:

where (Carn_port) and (Carn_art) are carnosine concentrations (µmol/L) in arterial and portal plasma, respectively, Hb_art and Hb_port are hemoglobin concentrations (g/L) in arterial and portal whole blood, respectively, and PPF is portal plasma flow (L/h).

in which PBF is portal blood flow (L/h) and PCV_port is PCV in portal blood (percent).

Statistical analyses

Values in the text are means ± SEM. Test meal effects on [Carn_art] and PNF_carn were statistically analyzed using the repeated option of PROC MIXED procedure of SAS (SAS/STAT Users Guide, Release 8.1; SAS Institute), with subjects as random effect and time, group, and time x group as factors. When significant time x group interaction was found, the LSMEANS procedure was used to test differences at specific times between groups and within groups vs. baseline. Postprandial area under the curve of PNF_carn was calculated integrating the difference between PA and observed value, using the trapezoidal method. These data, and data from Eq. 1, were analyzed by ANOVA with the GLM procedure of SAS, using a model with animal and test meal as independent variables. Means are considered significantly different at P < 0.05.

	Results

TOP ABSTRACT Introduction Materials and Methods Results Discussion LITERATURE CITED

 
    Meat carnosine. Carnosine content of grilled TL, S, grilled neck, and grilled brisket was 20.7, 7.2, 13.0, and 11.8 µmol/g of meat, respectively.

    Carnosine in the digestive tract (Exp.1). Pigs always ate the whole meal in <15 min. Carnosine concentration in jejunal content was not significantly different from 0 in PA, PP1, and PP2 samples with the control meal and in PA samples with meat meals. After meat ingestion, jejunal carnosine concentration was greater (P < 0.05) with the TL than with the S meal (0.82 ± 0.27 vs. 0.23 ± 0.01 mmol/g in PP1 and 0.17 ± 0.02 vs. 0.06 ± 0.03 mmol/g in PP2). Postprandial carnosine flow to the jejunum was greater (P < 0.05) for TL than for S (1.48 ± 0.27 vs. 0.35 ± 0.04 mmol/6 h, respectively). When expressed as a proportion of carnosine ingestion, this flow was not different between TL and S meals (P > 0.10) and accounted for 50% of carnosine intake. Carnosine flow to the jejunum was almost completed in the first 3 h following meal intake; PP1 accounted for 90% of the total postprandial flow for both meats.

    Portal vein net release of carnosine (Exp.2). Minipigs always ate the whole meal in <15 min. PBF during the PA period was 49 ± 2 mL · min^–1 · kg^–1. The time variations in PBF throughout the postprandial period were not affected by the nature of the meat. PBF increased by 20% during the first hour following the beginning of the meal and then gradually decreased to attain the level of the prefeeding period 2–3 h later.

Carnosine intake was 2246, 645, and 1494 µmol for TL, S, and NB, respectively. Whereas (Carn_art) was not affected by the ingestion of S, it sharply increased between 30 and 60 min after the meal of TL and NB (Fig. 1A). The same pattern was observed for portal carnosine concentration (Fig. 1B).

View larger version (12K): [in this window] [in a new window]   Figure 1  Carnosine concentrations in arterial (A) and portal plasma (B), and carnosine net release in the portal vein (C) of minipigs after ingestion of TL, S, or NB. Values are means ± SEM, n = 4. Data were analyzed by a mixed-model ANOVA and the time x group interaction was significant, P < 0.0001, for all 3 variables. Means at a time without a common letter differ, P < 0.05. Lines at the top of each panel encompass means for the corresponding symbol that differ from baseline, P < 0.05.

After consumption of all the meats, blood pH increased (Fig. 2A). Its variation with time was not affected by the type of meat. Postprandial pH increase was linearly related to the increase in blood HCO₃^– concentration (r² = 0.33; P < 0.0001) (data not shown).

View larger version (13K): [in this window] [in a new window]   Figure 2  Blood pH (A) and TAC of plasma (B) in minipigs after ingestion of TL, S, or NB. Values are means ± SEM, n = 4. Lines at the bottom of each panel encompass means for the corresponding symbol that differ from baseline, P < 0.05.

	Discussion

TOP ABSTRACT Introduction Materials and Methods Results Discussion LITERATURE CITED

 
In raw beef meat, reported carnosine concentrations range from 10 to 20 µmol/g (14–18). Differences between meat may be explained by the muscle oxidative patterns, carnosine level being lower in muscles with a high proportion of oxidative muscle fibers (14), by animal breed and production system (16,17) and by slaughter age (16). Carnosine level in beef meat is not affected by storage time (16,19) but can be altered by cooking. In grilled meat, carnosine concentration (in fresh matter) tends to increase (7,18), although it slightly decreased when expressed on the basis of the DM (18). In stewed red meat, decrease in carnosine concentration by up to 30% has been reported (19,20), which is consistent with the low level of carnosine observed in S in this study.

Dietary carnosine can be absorbed if it is not rapidly and fully hydrolyzed in the intestinal lumen. In our study, we observed in young pigs that, after a meat meal, about one-half of the ingested carnosine flowed to the mid jejunum. Whether the remaining carnosine was absorbed in the first part of the intestine or degraded is not known. In vitro studies suggested that carnosine in cooked meat was not very sensitive to pepsin and pancreatin digestion (21). Nonetheless, our data showed that even if carnosine was hydrolyzed in the gut lumen, this degradation was not rapid enough to prevent its absorption. Carnosine concentration in the intestinal lumen appeared to be related to the amount of ingested carnosine, intestinal concentrations being greater after TL ingestion than after S ingestion.

Gardner et al. (5) were the first, to our knowledge, to investigate the possibility of the intestinal absorption of intact carnosine in humans. They observed a substantial increase (80 µmol/L) in plasma carnosine concentration within the hour following oral administration of carnosine and a rapid decline in the next hour. In humans, plasma carnosine concentration increased (144 µmol/L) after consumption of a ground beef meal containing 267 mg carnosine (7). Although the magnitude of the variation was lower in our study (22 µmol/L with TL), the increase in minipig plasma carnosine concentration showed a similar pattern: rapid increase during the first postfeeding hours, maximum concentrations 2–3 h postfeeding, and return to baseline 6–7 h postfeeding. Furthermore, maximal values of plasma carnosine were closely related to carnosine intake. Plasma concentrations remain difficult to interpret, because they result from entry rate in plasma (endogenous production and intestinal absorption) and disappearance rate (degradation, uptake by tissues). In this study, the minipig model allowed us to focus on carnosine intestinal absorption.

After carnosine oral administration in humans, carnosine excretion in the urine was shown to account for up to 14% of ingested carnosine (5). From these data, it was, however, not possible to quantify true intestinal absorption. If we assume no significant uptake of arterial carnosine and no significant synthesis of carnosine by the portal drained viscera, portal net release of carnosine reflects intestinal absorption. In this study, the portal net release of carnosine accounted for 22% of the intake for TL and the NB blend. Surprisingly, no significant portal net flux of carnosine was detected after S intake, and there was no significant increase in arterial carnosine. Cooking conditions for S were more drastic than for the other meats and a lower small intestinal digestibility of carnosine might be suspected. Indeed, although no difference in jejunal digestibility between TL and S was detected in the digestion study, carnosine adduct formation during prolonged cooking may reduce carnosine digestibility in the distal part of the small intestine. The absence of carnosine net release into the portal vein could also be due to a threshold effect: below 700 µmol of carnosine ingested, all dietary carnosine would be sequestrated in the small intestine. Above this value, carnosine net release in blood would be proportional to carnosine intake. This threshold for carnosine net release in bloodstream would be mainly related to an overflow of the intestinal carnosinase activity.

Among its different potential activities, carnosine pH buffering capacity is the most widely accepted. In this study, because of the high protein content of the meals, a postprandial decrease in pH could have been expected as a consequence of oxidation of S-containing amino acids to H₂SO₄. Conversely, blood pH increased after the meal regardless of which meat was ingested. This increase was mainly related to the postprandial increase in blood bicarbonate, leading to the recognized postprandial alkaline tide (22). Under these conditions, it was impossible to detect any anti-acidosis effect of dietary carnosine in blood. Nevertheless, in humans, oral supplementation with chicken breast extract, which is a rich source of histidine dipeptide, enhanced nonbicarbonate blood pH buffering during intense intermittent exercise (23).

In humans, serum TAC increased after a meat meal without any contribution of serum urate level increase and a similar increase was observed after oral administration of carnosine alone (24). In this study, we also observed a postprandial increase in plasma TAC level after a meat meal in minipigs. Although it was impossible to relate this increase in plasma TAC to carnosine meat content, regression analysis showed that up to 30% of TAC variations could be explained by plasma carnosine increase.

In conclusion, the results of this study provide further evidence that small peptides can cross small intestinal epithelium and reach the bloodstream. After a meal of meat, a significant amount of carnosine is released into the portal blood, depending on the amount of carnosine intake. Given its numerous health benefits, carnosine should be considered when defining the nutritional value of meat.

	ACKNOWLEDGMENTS

 
The authors thank D. Durand for surgical preparation of the pigs, C. Lafarge for pig care, and C. Cossoul and C. Buffière for technical assistance.

	FOOTNOTES

 
¹ Supported by OFIVAL (Office National Interprofessionnel des Viandes, de l'Elevage et de l'Aviculture), France, INTERBEV (Association Nationale Interprofessionnel du Bétail et des Viandes), France, and INRA (French National Institute of Agricultural Research), France.

⁶ Abbreviations used: DM, dry matter; NB, blend of grilled neck and brisket; PA, postabsorptive; PBF, portal blood flow; PCV, packed cell volume; PNF_carn, portal net flux of carnosine in plasma; PP1, first 3 h postprandial period; PP2, last 3 h postprandial period; S, stewed shoulder; TAC, total antioxidant capacity; TL, grilled top loin; Yb, Ytterbium.

Manuscript received 3 October 2006. Initial review completed 26 October 2006. Revision accepted 13 December 2006.

	LITERATURE CITED

TOP ABSTRACT Introduction Materials and Methods Results Discussion LITERATURE CITED

 

1. Boldyrev AA, Severin SE. The histidine-containing dipeptides, carnosine and anserine: distribution, properties and biological significance. Adv Enzyme Regul. 1990;30:175–94.[Medline]

2. Abe H. Role of histidine-related compounds as intracellular proton buffering constituents in vertebrate muscle. Biochemistry (Mosc). 2000;65:757–65.[Medline]

3. Guiotto A, Calderan A, Ruzza P, Borin G. Carnosine and carnosine-related antioxidants: a review. Curr Med Chem. 2005;12:2293–315.[Medline]

4. Hipkiss AR, Brownson C, Bertani MF, Ruiz E, Ferro A. Reaction of carnosine with aged proteins: another protective process. Ann N Y Acad Sci. 2002;959:285–94.[Medline]

5. Gardner LLG, Illingworth KM, Kelleher J, Wood D. Intestinal absorption of the intact peptide carnosine in man, and comparison with intestinal permeability to lactulose. J Physiol. 1991;439:411–22.[Abstract/Free Full Text]

6. Hipkiss AR. Glycation, ageing and carnosine: are carnivorous diets beneficial? Mech Ageing Dev. 2005;126:1034–9.[Medline]

7. Park YJ, Volpe SL, Decker EA. Quantitation of carnosine in humans plasma after dietary consumption of beef. J Agric Food Chem. 2005;53:4736–9.[Medline]

8. Son DO, Satsu H, Kiso Y, Shimizu M. Characterization of carnosine uptake and its physiological function in human intestinal epithelial Caco-2 cells. Biofactors. 2004;21:395–8.[Medline]

9. Irie M, Terada T, Okuda M, Inui K. Efflux properties of basolateral peptide transporter in human intestinal cell line Caco-2. Pflugers Arch. 2004;449:186–94.[Medline]

10. Lenney JF, Peppers SC, Kucera-Orallo CM, George RP. Characterization of human tissue carnosinase. Biochem J. 1985;228:653–60.[Medline]

11. Rémond D, Ortigues-Marty I, Isserty A, Lefaivre J. Technical note: measuring portal blood flow in sheep using an ultrasonic transit time flow probe. J Anim Sci. 1998;76:2712–6.[Abstract/Free Full Text]

12. Williams S. Official methods of analysis of the Association of Official Analytical Chemists, 14th ed. Arlington (VA): AOAC; 1984.

13. Maynard LM, Boissonneault GA, Chow CK, Bruckner GG. High levels of dietary carnosine are associated with increased concentrations of carnosine and histidine in rat soleus muscle. J Nutr. 2001;131:287–90.[Abstract/Free Full Text]

14. Rao MV, Gault NFS. The influence of fiber-type composition and associated biochemical characteristics on the acid buffering capacities of several beef muscles. Meat Sci. 1989;26:5–18.

15. Aristoy MC, Toldra F. Histidine dipeptides HPLC-based test for the detection of mammalian origin proteins in feeds for ruminants. Meat Sci. 2004;67:211–7.

16. Watanabe A, Ueda Y, Higuchi M. Effects of slaughter age on the levels of free amino acids and dipeptides in fattening cattle. Anim Sci J. 2004;75:361–7.

17. Purchas RW, Busboom J. The effect of production system and age on levels of iron, taurine, carnosine, coenzyme q(10), and creatine in beef muscles and liver. Meat Sci. 2005;70:589–96.

18. Purchas RW, Rutherfurd SM, Pearce PD, Vather R, Wilkinson BHP. Cooking temperature effects on the forms of iron and levels of several other compounds in beef semitendinosus muscle. Meat Sci. 2004;68:201–7.

19. Bauchart C, Rémond D, Chambon C, Patureau Mirand P, Savary-Auzeloux I, Reynès C, Morzel M. Small peptides (<5 kDa) found in ready-to-eat beef meat. Meat Sci. 2006;74:658–66.

20. Purchas RW, Rutherfurd SM, Pearce PD, Vather R, Wilkinson BHP. Concentrations in beef and lamb of taurine, carnosine, coenzyme Q₁₀, and creatine. Meat Sci. 2004;66:629–37.

21. Purchas RW, Busboom JR, Wilkinson BHP. Changes in the forms of iron and in concentrations of taurine, carnosine, coenzyme Q₁₀, and creatine in beef longissimus muscle with cooking and simulated stomach and duodenal digestion. Meat Sci. 2006;74:443–9.

22. Moore EW. The alkaline tide. Gastroenterology. 1967;52:1052–4.[Medline]

23. Suzuki Y, Nakao T, Maemura H, Sato M, Kamahara K, Morimatsu F, Takamatsu K. Carnosine and anserine ingestion enhances contribution of nonbicarbonate buffering. Med Sci Sports Exerc. 2006;38:334–8.

24. Antonini FM, Petruzzi E, Pinzani P, Orlando C, Poggesi M, Serio M, Pazzagli M, Masotti G. The meat in the diet of aged subjects and the antioxidant effects of carnosine. Arch Gerontol Geriatr. 2002; 35(suppl. 1) 8:7–14.[Medline]

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