Intestinal absorption of carnosine and its constituent amino acids in man

Asatoor, A. M.; Bandoh, J. K.; Lant, A. F.; Milne, M. D.; Navab, Farhad

doi:10.1136/gut.11.3.250

Cited by 69 publications

(43 citation statements)

References 15 publications

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“…No adverse effects were caused by carnosine ingestion although some subjects experienced mild and transient digital paraesthesia within the first hour, a similar effect having been reported by Asatoor, Bandoh, Lant, Milne & Navab (1970). Figure 1 shows the urinary content of carnosine over the first 5 h after ingestion of 4 g of carnosine by six subjects.…”

Section: Urinary Output Of Carnosinesupporting

confidence: 56%

See 1 more Smart Citation

Intestinal absorption of the intact peptide carnosine in man, and comparison with intestinal permeability to lactulose.

Gardner

Illingworth

Kelleher

et al. 1991

The Journal of Physiology

139

107

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SUMMARY Healthy humans ingested the dipeptide carnosine (L-/I-alanyl-L-histidine).Their plasma levels and urinary outputs of carnosine and ,8-alanine were monitored over the following 5 h.2. Large amounts of intact carnosine (up to 14 % of the ingested dose) were recovered in the urine over the 5 h after ingestion. However, carnosine was undetectable in the plasma unless precautions were taken to inhibit blood carnosinase activity ex vivo during and after blood collection.3. The amount of carnosine recovered in urine varied substantially between subjects. It correlated negatively with carnosinase enzymic activity in the plasma. Highest carnosinase activities were observed in those subjects who regularly underwent physical training.4. Urinary recovery of the disaccharide lactulose also varied considerably between subjects, but was substantially lower than that of carnosine. There was no significant correlation between the recoveries of carnosine and lactulose. 5. When lactulose was ingested with a hypertonic solution, the urinary recovery of lactulose was generally increased. When carnosine was ingested with a hypertonic solution, the urinary recovery of carnosine was reduced: hence the paracellular route probably is not dominant for absorption of intact carnosine.6. Intact carnosine must have crossed the intestine to an extent much greater than hitherto recognized. Rapid post-absorptive hydrolysis is a severe obstacle to quantification of intact peptide absorption.

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Section: Urinary Output Of Carnosinesupporting

confidence: 56%

“…The presence of such effective carnosinase activity in plasma explains why Asatoor et al (1970) and Sadikali et at. (1975) failed to detect carnosine in plasma after carnosine ingestion by humans.…”

Section: Discussionmentioning

confidence: 99%

Intestinal absorption of the intact peptide carnosine in man, and comparison with intestinal permeability to lactulose.

Gardner

Illingworth

Kelleher

et al. 1991

The Journal of Physiology

139

107

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“…As Gardner et al reported, no adverse effects were observed aside from a mild and transient digital paraesthesia that some subjects experienced within the first hour. Paraesthesia occurring from about 15-45 min after the ingestion of *2.5 g of carnosine (0.286 mmol/kg body weight) was also reported by Asatoor et al (1970).…”

Section: Negative Side Effectsmentioning

confidence: 61%

“…Initial attempts to measure plasma levels of carnosine in human probands have not yielded reliable data (Asatoor et al 1970); it was shown that ex vivo hydrolysis during blood collection resulted in an apparent half-life of carnosine of the order of 1 min (Gardner et al 1991). Although this does not reflect carnosine's biological halflife in serum, the fact that urinary recovery of carnosine is possible by the fourth hour after ingestion poses a question to the fate of absorbed carnosine before excretion.…”

Section: Plasma Levels Of Carnosinementioning

confidence: 99%

Carnosine and cancer: a perspective

Gaunitz

Hipkiss

2012

Amino Acids

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The application of carnosine in medicine has been discussed since several years, but many claims of therapeutic effects have not been substantiated by rigorous experimental examination. In the present perspective, a possible use of carnosine as an anti-neoplastic therapeutic, especially for the treatment of malignant brain tumours such as glioblastoma is discussed. Possible mechanisms by which carnosine may perform its anti-tumourigenic effects are outlined and its expected bioavailability and possible negative and positive side effects are considered. Finally, alternative strategies are examined such as treatment with other dipeptides or b-alanine.

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“…These findings are in accordance with the earlier in vivo and in vitro studies (Scriver, Pueschel & Davies, 1966;Goldman & Scriver, 1967;Nutzenadel & Scriver, 1976;Dantzler & Silbernagl, 1976) which indicated that in the kidney ,-amino acids share a common transport system which is different from that for oc-amino acids. In addition to the kidney, a transport system specific for f-amino acids was reported in intestine (Asatoor, Bandoh, Lant, Milne & Navab, 1970) and in Ehrlich ascite tumour cells (Christensen, 1964 …”

Section: Discussionmentioning

confidence: 99%

Demonstration of H+‐ and Na+‐coupled co‐transport of beta‐alanine by luminal membrane vesicles of rabbit proximal tubule.

Jessen

Jørgensen

Røigaard-Petersen

et al. 1989

The Journal of Physiology

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SUMMARY1. The characteristics of renal transport of ,-alanine by luminal membrane vesicles isolated from either the proximal convoluted part (pars convoluta) or the proximal straight part (pars recta) of rabbit proximal tubule were investigated.2. In vesicles from pars convoluta two transport systems have been characterized: (1) a Na+-dependent system with intermediate affinity (half-saturation 2-7 mM), and (2) a Na+-independent system, which in the presence of a H+ gradient (extravesicular > intravesicular) can drive the uphill transport of f,-alanine into these vesicles. This is the first demonstration of H+-,-alanine co-transport across luminal membrane of rabbit kidney proximal convoluted tubule.3. By contrast, in membrane vesicles from pars recta, transport of fi-alanine was strictly dependent on Na+ and occurred via a dual transport system, namely a highaffinity (half-saturation 0-16 mM) and a low-affinity system (half-saturation 9-3 mM).4. The demonstration of competition between the Na+-gradient-dependent uptake of 8i-alanine and taurine, without appreciable inhibition by a-amino acids in vesicles from pars convoluta as well as from pars recta, strongly suggests that the luminal membrane of proximal tubule has transport systems for the reabsorption of ,f-amino acids which are distinct from a-amino acid transport systems.

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Intestinal absorption of carnosine and its constituent amino acids in man

Cited by 69 publications

References 15 publications

Intestinal absorption of the intact peptide carnosine in man, and comparison with intestinal permeability to lactulose.

Intestinal absorption of the intact peptide carnosine in man, and comparison with intestinal permeability to lactulose.

Carnosine and cancer: a perspective

Demonstration of H+‐ and Na+‐coupled co‐transport of beta‐alanine by luminal membrane vesicles of rabbit proximal tubule.

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