Utilization of urea nitrogen in Papua New Guinea highlanders.

Rikimaru, Toru; Fujita, Yoshiaki; Okuda, Toyoko; Kajiwara, Naemi; Date, Chigusa; Heywood, Peter; Alpers, Michael P.; Koishi, Hideo

doi:10.3177/jnsv.31.393

Cited by 20 publications

(15 citation statements)

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“…Rikimaru et al (1985) used 15 N in feces as a tracer among Papua New Guinea highlanders to measure urea nitrogen recovery and utilization as a strategy for coping with protein stress. Among non-human primates, fecal stable isotope data have been used to show that the weaning process among captive Trachypithecus francoisi is more protracted than what was expected based on observation alone (Reitsema, 2012) and to compare resource use by Papio ursinis inhabiting different environments (Codron et al, 2006).…”

Section: Methods For Collection and Preparation Of Different Tissue Tmentioning

confidence: 99%

“…N signatures from humans have shown a local adaptation to urea metabolism among New Guinea highlanders, reflecting chronically low-protein diets (Rikimaru et al, 1985). Among non-human primates, d N compared to under conditions of sufficient protein, reflecting catabolism of endogenous tissues to meet nutritional demands of the body (Deschner et al, 2012;Vogel et al, 2012).…”

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confidence: 99%

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Laboratory and field methods for stable isotope analysis in human biology

Reitsema

2015

American J Hum Biol

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Stable isotope analysis (SIA; carbon, hydrogen, nitrogen, sulfur, and oxygen) of human tissues offers a means for assessing diet among living humans. Stable isotope ratios of broad categories of food and drink food vary systematically, and stable isotope ratios in consumer tissues represent a composite of the isotopic ratios of food and drink consumed during an individual's life. Isotopic evidence for diet is independent of errors in informant recall, and accrues during time periods when researchers are absent. Beyond diet reconstruction, tissue stable isotope ratios are sensitive to excursions from homeostasis, such as starvation and rapid growth. Because of their relationship to diet, geographic location, hydration, and nutritional status, stable isotope signatures in human tissues offer a window into human biocultural adaptations, past and present. This article describes methods for SIA that may be usefully applied in studies of living humans, with emphasis placed on carbon and nitrogen. Some of the ecological, physiological, and evolutionary applications of stable isotope data among living humans are discussed. By incorporating SIA in research, human biologists facilitate a productive dialog with bioarchaeologists, who routinely use stable isotope evidence, mingling different perspectives on human biology and behavior.

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Section: Methods For Collection and Preparation Of Different Tissue Tmentioning

confidence: 99%

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confidence: 99%

Laboratory and field methods for stable isotope analysis in human biology

Reitsema

2015

American J Hum Biol

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“…Although there were some days in our study when the orangutans consumed as little as 12.6 g/d of protein, during low fruit periods they still maintained an average of 54.0±33.6 g/d. In a study on Papua New Guinea highlanders who have a low-protein diet, average protein intake was 32.2±8.6 g/d (Rikimaru et al 1985). Thus, perhaps the orangutan's protein intake in our study never fell below critical values necessary to enter into a negative N balance state.…”

Section: Discussionmentioning

confidence: 84%

A Noninvasive Method for Estimating Nitrogen Balance in Free-Ranging Primates

et al. 2011

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The vital role of body protein as an energy reserve has received little focus in studies of wild primates. Owing to the relatively low protein content of fruit, some frugivorous primates could face a protein deficit if body protein is catabolized for energy during periods of low fruit availability. Such an imbalance can be detected if fatty acids, amino acids, and nitrogen (N) catabolites are reincorporated or recycled back to tissues. Here we describe a method to quantify protein recycling by measuring standardized urea concenInt J Primatol (tration and N isotope signatures from urine samples collected from wild Bornean orangutans (Pongo pygmaeus wurmbii). Our overall goal was to explore if concentrations of urea and δ 15 N values could be used as indicators of the amount of protein consumed and the degree of protein recycling, respectively, in wild, freeranging primates. We examine the relationships between urea concentration, δ 15 N values, protein intake, and fruit availability. Urea concentration increased with fruit availability, reflecting a slight increase in protein consumption when fruit was abundant. However, we found no relationship between δ 15 N values and fruit availability, suggesting that orangutans avert a negative protein balance during periods of low fruit availability. These noninvasive methods complement recent advances in primate energy balance research and will contribute to our understanding of adaptations of primates during periods of fruit shortage.

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“…We compared the degree of urea utilization between healthy PNG highlanders and Japanese subjects in relation to level of protein intake. TANAKA et al (1980) andRIKIMARU et al (1985) tried to make clear the mechanism of the utilization of urea in PNG highlander's diet which was composed mainly of sweet potatoes. The protein level on that diet was the same as with LPD in this experiment.…”

Section: Discussionmentioning

confidence: 99%

“…In order to determine the subjects' utilization of urea in reference to their food habits, we estimated the 15N nitrogen in serum protein after administering 15N -labelled urea to groups living among the PNG Eastern Highlands on habitual diets (TANAKA et al, 1980;RIKIMARU et al, 1985). 15N had been incorporated into serum protein on habitual diet 3 days after the administration of the 15N urea.…”

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confidence: 99%

Effect of dietary protein levels on urea utilization in Papua New Guinea highlanders.

et al. 1986

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Ability to utilize urea nitrogen for body protein synthesis was examined with Papua New Guinea (PNG) highlanders and Japanese (JPN). Eight male PNG highlanders and 8 male JPN were fed on a low protein diet containing 0.55 g protein/kg or an adequate protein diet containing l.34 g protein/kg for 1 or 2 weeks. The fate of 15N was measured after oral administration of 15N-labelled urea. There was no difference in 15N incorporation into serum protein between PNG highlanders and JPN receiving low protein diets. On the other hand, on the adequate protein diet, 15N incorporation in PNG highlanders was similar to that on the low protein diet, in contrast to that in JPN which was hardly detected in the adequate protein diet. When PNG highlanders take more protein than protein in their usual diet, they effectively incorporate ingested protein into their body protein and urea nitrogen is utilized for synthesis of body protein.

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Utilization of urea nitrogen in Papua New Guinea highlanders.

Cited by 20 publications

References 14 publications

Laboratory and field methods for stable isotope analysis in human biology

Laboratory and field methods for stable isotope analysis in human biology

A Noninvasive Method for Estimating Nitrogen Balance in Free-Ranging Primates

Effect of dietary protein levels on urea utilization in Papua New Guinea highlanders.

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