The entry of acidic amino acids into brain and CSF during development, using in situ perfusion in the rat

Amino acid transport by juxtamedullary (JM) nephrons and its relationship to transport by superficial cortical (SC) nephrons and to function of vasa recta and collecting ducts were examined in vivo and in situ by free-flow micropuncture of Henle's loops, collecting ducts, and vasa recta and by continuous microinfusion of Henle's loops in exposed rat papillae. Fractional deliveries (FDs) of six neutral amino acids, two acidic amino acids, and taurine to tips of Henle's loops of JM nephrons could be substantially below those to early distal loops of SC nephrons, indicating that reabsorption before loop tips could be greater in JM than in SC nephrons. FDs to collecting ducts lower than to JM loop tips suggested reabsorption distal to loop tips. This was confirmed by continuous microinfusion of ascending limbs of Henle's loops. Distal site of reabsorption is unknown, but amino acids may move passively out of the thin ascending limb and be recycled into vasa recta and descending limb. Recycling of amino acids was supported by high FDs to tips of Henle's loops (sometimes greater than 1.0), higher concentrations in ascending than in descending vasa recta at same papilla level, and high mean concentrations in vasa recta.

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In situ synthesis carbonated hydroxyapatite layers on enamel slices with acidic amino acids by a novel two-step method

Materials Science and Engineering C ◽

10.1016/j.msec.2015.05.006 ◽

2015 ◽

Vol 54 ◽

pp. 150-157 ◽

Cited By ~ 6

Author(s):

Xiaoguang Wu ◽

Xu Zhao ◽

Yi Li ◽

Tao Yang ◽

Xiujuan Yan ◽

...

Keyword(s):

Amino Acids ◽

In Situ Synthesis ◽

Step Method ◽

Carbonated Hydroxyapatite ◽

Acidic Amino Acids

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Oleacein Intestinal Permeation and Metabolism in Rats Using an In Situ Perfusion Technique

Pharmaceutics ◽

10.3390/pharmaceutics13050719 ◽

2021 ◽

Vol 13 (5) ◽

pp. 719

Author(s):

Anallely López-Yerena ◽

Maria Pérez ◽

Anna Vallverdú-Queralt ◽

Eleftherios Miliarakis ◽

Rosa M. Lamuela-Raventós ◽

...

Keyword(s):

Intestinal Permeability ◽

Model Compound ◽

Virgin Olive Oil ◽

Extra Virgin Olive Oil ◽

Perfusion Technique ◽

In Situ Perfusion ◽

First Pass ◽

Health Promoting ◽

Intestinal Permeation

Oleacein (OLEA) is one of the most important phenolic compounds in extra virgin olive oil in terms of concentration and health-promoting properties, yet there are insufficient data on its absorption and metabolism. Several non-human models have been developed to assess the intestinal permeability of drugs, among them, single-pass intestinal perfusion (SPIP), which is commonly used to investigate the trans-membrane transport of drugs in situ. In this study, the SPIP model and simultaneous luminal blood sampling were used to study the absorption and metabolism of OLEA in rats. Samples of intestinal fluid and mesenteric blood were taken at different times and the ileum segment was excised at the end of the experiment for analysis by LC–ESI–LTQ–Orbitrap–MS. OLEA was mostly metabolized by phase I reactions, undergoing hydrolysis and oxidation, and metabolite levels were much higher in the plasma than in the lumen. The large number of metabolites identified and their relatively high abundance indicates an important intestinal first-pass effect during absorption. According to the results, OLEA is well absorbed in the intestine, with an intestinal permeability similar to that of the highly permeable model compound naproxen. No significant differences were found in the percentage of absorbed OLEA and naproxen (48.98 ± 12.27% and 43.96 ± 7.58%, respectively).

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A facile one pot route for the synthesis of imide tethered peptidomimetics

Organic & Biomolecular Chemistry ◽

10.1039/c5ob01708d ◽

2016 ◽

Vol 14 (2) ◽

pp. 556-563 ◽

Cited By ~ 6

Author(s):

Veladi Panduranga ◽

Girish Prabhu ◽

Roopesh Kumar ◽

Basavaprabhu Basavaprabhu ◽

Vommina V. Sureshbabu

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Efficient Method ◽

One Pot ◽

Protected Amino Acid

A simple and efficient method for the synthesis of N,N’-orthogonally protected imide tethered peptidomimetics is presented. The imide peptidomimetics were synthesized by coupling the in situ generated selenocarboxylate of Nα-protected amino acids with Nα-protected amino acid azides in good yields.

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The Suitability of an in Situ Perfusion Model for Permeability Determinations: Utility for BCS Class I Biowaiver Requests

Molecular Pharmaceutics ◽

10.1021/mp060042f ◽

2006 ◽

Vol 3 (6) ◽

pp. 686-694 ◽

Cited By ~ 105

Author(s):

Jae-Seung Kim ◽

Stefanie Mitchell ◽

Paul Kijek ◽

Yasuhiro Tsume ◽

John Hilfinger ◽

...

Keyword(s):

Class I ◽

In Situ Perfusion ◽

Perfusion Model

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EFFECT OF IN SITU PERFUSION OF DONOR LUNG ON THE SURVIVAL OF CANINE LUNG ALLOGRAFT

Transplantation Journal ◽

10.1097/00007890-197202000-00022 ◽

1972 ◽

Vol 13 (2) ◽

pp. 183-186 ◽

Cited By ~ 4

Author(s):

Hajime Iwahashi ◽

Hiroshi Nagaya ◽

Will C. Sealy

Keyword(s):

In Situ Perfusion ◽

Donor Lung

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In situ studies on alginic acid synthesis and other aspects of the metabolism of Laminaria digitata

Canadian Journal of Botany ◽

10.1139/b72-023 ◽

1972 ◽

Vol 50 (1) ◽

pp. 177-184 ◽

Cited By ~ 10

Author(s):

Johan A. Hellebust ◽

Arne Haug

Keyword(s):

Amino Acids ◽

Time Course ◽

Alginic Acid ◽

Acid Synthesis ◽

Short Term ◽

Fresh Weight Basis ◽

Mannuronic Acid ◽

Guluronic Acid ◽

Rate Of Photosynthesis

Amino acids, particularly alanine and aspartate, become more strongly labeled than mannitol in short-term 14C-photoassimilation experiments. The amino acids are the most likely sources of carbon for alginic acid synthesis and respiration in the dark, in contrast to mannitol, which appears to be relatively unavailable. Temperature is very important in determining the rate of loss of recent photoassimilate in L. digitata. The rate of photosynthesis, on a fresh weight basis, is much higher for blades than for stipes.The time course for incorporation of photoassimilated carbon into alginate differs for the stipe and blade both in light and dark periods. Very little 14C enters alginate in blades in the dark, while alginate in stipes acquires considerable amounts of activity during dark periods. Alginate in both blade and stipe acquires 14C predominantly in mannuronic acid residues of their alginate during short-term photoassimilation periods, while guluronic acid residues become relatively more rapidly labeled during dark periods.

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