In vivo antidiabetic activity of nimesulide due to inhibition of amino acid transport

Abstract. Groups of immature mice were injected sc with radiocarbon-labelled alpha-aminoisobutyric acid (AIB) after being given a single sc injection of hFSH or of 0.9% saline. As an index of the transport of AIB, the specific activity of isotope was measured in homogenates of testis and of liver. FSH treatment caused statistically significant increases in the specific activity of isotope in the testes and in the ratio of testicular to liver specific activity. The effect was greatest in 9-day-old mice injected with FSH 16 h before removal of the testes. Uptake of labelled AIB was not stimulated after administration of hCG or testosterone. Doses of cycloheximide sufficient to reduce the rate of protein synthesis by over 99% did not impair testicular uptake of labelled AIB or the influence of FSH on AIB uptake. These results suggest that FSH stimulates amino acid transport into cells of the immature testis and that this action is independent of the stimulatory effect of FSH on testicular protein synthesis.

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Amino acid transport by juxtamedullary nephrons: distal reabsorption and recycling

AJP Renal Physiology ◽

10.1152/ajprenal.1988.255.3.f397 ◽

1988 ◽

Vol 255 (3) ◽

pp. F397-F407 ◽

Cited By ~ 2

Author(s):

W. H. Dantzler ◽

S. Silbernagl

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Amino Acid Transport ◽

Acid Transport ◽

Acidic Amino Acids ◽

Vasa Recta ◽

Collecting Ducts ◽

Distal Site

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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Nature of Cd and Hg effects on epithelial amino acid transport in vivo and role of chelators

Toxicology ◽

10.1016/0300-483x(91)90229-t ◽

1991 ◽

Vol 69 (2) ◽

pp. 177-185 ◽

Cited By ~ 12

Author(s):

E.C. Foulkes

Keyword(s):

Amino Acid ◽

Amino Acid Transport ◽

Acid Transport

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Insulin and insulin inhibitor on amino acid transport in rat diaphragm in vivo

Biochimica et Biophysica Acta (BBA) - Biomembranes ◽

10.1016/0005-2736(75)90397-1 ◽

1975 ◽

Vol 389 (1) ◽

pp. 194-197 ◽

Cited By ~ 5

Author(s):

D.A.B. Young ◽

T. Clausen ◽

L. Balant

Keyword(s):

Amino Acid ◽

Amino Acid Transport ◽

Rat Diaphragm ◽

Acid Transport ◽

Insulin Inhibitor

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Reduction of In Vivo Placental Amino Acid Transport Precedes the Development of Intrauterine Growth Restriction in the Non-Human Primate

Nutrients ◽

10.3390/nu13082892 ◽

2021 ◽

Vol 13 (8) ◽

pp. 2892

Author(s):

Fredrick J. Rosario ◽

Anita Kramer ◽

Cun Li ◽

Henry L. Galan ◽

Theresa L. Powell ◽

...

Keyword(s):

Amino Acid ◽

Amino Acid Transport ◽

Intrauterine Growth Restriction ◽

Growth Restriction ◽

Acid Transport ◽

Mole Percent ◽

System A ◽

System L ◽

Human Primate

Intrauterine growth restriction (IUGR) is associated with reduced placental amino acid transport (AAT). However, it remains to be established if changes in AAT contribute to restricted fetal growth. We hypothesized that reduced in vivo placental AAT precedes the development of IUGR in baboons with maternal nutrient restriction (MNR). Baboons were fed either a control (ad libitum) or MNR diet (70% of control diet) from gestational day (GD) 30. At GD 140, in vivo transplacental AA transport was measured by infusing nine (13)C- or (2)H-labeled essential amino acids (EAAs) as a bolus into the maternal circulation at cesarean section. A fetal vein-to-maternal artery mole percent excess ratio for each EAA was measured. Microvillous plasma membrane (MVM) system A and system L transport activity were determined. Fetal and placental weights were not significantly different between MNR and control. In vivo, the fetal vein-to-maternal artery mole percent excess ratio was significantly decreased for tryptophan in MNR. MVM system A and system L activity was markedly reduced in MNR. Reduction of in vivo placental amino acid transport precedes fetal growth restriction in the non-human primate, suggesting that reduced placental amino acid transfer may contribute to IUGR.

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A Comparison of Amino Acid Transport and Ouabain Binding in Brain Endothelium and Salivary Epithelium Studied in vivo by Rapid Paired-Tracer Dilution

Transport Mechanisms of Tryptophan in Blood Cells, Nerve Cells, and at the Blood-Brain Barrier ◽

10.1007/978-3-7091-2243-3_2 ◽

1979 ◽

pp. 15-27

Author(s):

D. L. Yudilevich ◽

F. V. Sepúlveda ◽

J. C. Bustamante ◽

G. E. Mann

Keyword(s):

Amino Acid ◽

Amino Acid Transport ◽

Brain Endothelium ◽

Acid Transport ◽

Ouabain Binding ◽

Tracer Dilution ◽

Paired Tracer Dilution

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Effect of bile salts on amino acid transport by rabbit intestine

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1975.229.2.518 ◽

1975 ◽

Vol 229 (2) ◽

pp. 518-523 ◽

Cited By ~ 18

Author(s):

JJ Hajjar ◽

RN Khuri ◽

AB Bikhazi

Keyword(s):

Amino Acid ◽

Amino Acid Transport ◽

Bile Salts ◽

Acid Transport ◽

Histological Changes ◽

Surface Active Agents ◽

Rabbit Intestine ◽

Minimal Reduction

The effect of bile salts on alanine absorption across four regional sites of rabbit intestine was examined using an in vivo single-pass perfusion technique. Na-deoxycholate at a concentration of 3 mM reduced alanine absorption across all levels of the intestine, and a higher concentration (10 mM) of Na-taurodeoxycholate (TDC) caused only a minimal reduction of alanine absorption in the jejunum. TDC, however, was more effective in in vitro experiments, causing an incrase in transmural serosal-to-mucosal flux of alanine and phenylalanine, particularly when present in both the mucosal and serosal media. It also reduced the mucosal-to-serosal alanine flux rate when present only in the mucosal medium. The influx of these amino acids across the mucosal brush border membrane was also decreased by TDC. These amino acid transport changes correlated fairly well with some observed histological changes of the intestinal epithelium. This suggests that bile salt inhibition of amino acid absorption is nonspecific in type and can be mainly explained as being the result of an injurious action of these surface-active agents on the rabbit intestine.

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