کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10818994 | 1060291 | 2011 | 14 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Phylogenetic constraints on digesta separation: Variation in fluid throughput in the digestive tract in mammalian herbivores
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The relevance of the mean retention time (MRT) of particles through the gastrointestinal tract (GIT) is well understood and MRTparticleGIT is an important parameter in digestion models. Solute markers have been used to estimate MRTsoluteGIT (or 'fluid passage') in animals, but the relevance of this measure is less evident and is usually sought in its relation to MRTparticleGIT. The ratio between the two measures indicates the degree of 'digesta washing', with little washing occurring at ratios of 1, aborad washing at ratios >Â 1 (where the solute marker travels faster than the particle marker), and orad (retrograde) washing at ratios <Â 1 (where the solute marker travels slower than the particle marker). We analysed digesta washing in a dataset of 98 mammalian species including man of different digestion types (caecum, colon and nonruminant foregut fermenters, and ruminants), controlling for phylogeny; a subset of 72 species allowed testing for the influence of food intake level. The results indicate that MRTsoluteGIT and the degree of digesta washing are related to digestion type, whereas variation in MRTparticleGIT is influenced mainly by effects of body mass and food intake. Thus, fluid throughput and digesta washing emerge as important correlates of digestive anatomy. Most importantly, primates appear constrained to little digesta washing compared to non-primate mammalian herbivores, regardless of their digestion type. These results may help explain the absence of primates from certain herbivore niches and represent a drastic example of a physiologic limitation in a phylogenetic group. More experimental research is required to illuminate relative benefits and costs of digesta washing.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology - Volume 160, Issue 2, October 2011, Pages 207-220
Journal: Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology - Volume 160, Issue 2, October 2011, Pages 207-220
نویسندگان
Dennis W.H. Müller, Judith Caton, Daryl Codron, Angela Schwarm, Roger Lentle, W. Jürgen Streich, Jürgen Hummel, Marcus Clauss,