Net Amino Acid Flux across the Fetal Liver and Placenta during Spontaneous Ovine Parturition

Neonatology ◽  
2001 ◽  
Vol 79 (1) ◽  
pp. 54-60 ◽  
Author(s):  
Michelle Timmerman ◽  
Cecilia Teng ◽  
Randall B. Wilkening ◽  
Misoo Chung ◽  
Frederick C. Battaglia
Keyword(s):  
Amino Acid ◽  
Fetal Liver ◽  
Amino Acid Flux

scholarly journals Neuromedin U receptors (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database

2019 ◽  
Vol 2019 (4) ◽  
Author(s):  
Khaled Al-hosaini ◽  
Stephen R. Bloom ◽  
Joseph Hedrick ◽  
Andrew Howard ◽  
Preeti Jethwa ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Bone Marrow ◽  
Amino Acid ◽  
Species Differences ◽  
Fetal Liver ◽  
Single Gene ◽  
Acid Product ◽  
Amino Acid Peptide ◽  
Upper Gastrointestinal ◽  
Sole Product

Neuromedin U receptors (provisional nomenclature as recommended by NC-IUPHAR [29]) are activated by the endogenous 25 amino acid peptide neuromedin U (neuromedin U-25, NmU-25), a peptide originally isolated from pig spinal cord [90]. In humans, NmU-25 appears to be the sole product of a precursor gene (NMU, P48645) showing a broad tissue distribution, but which is expressed at highest levels in the upper gastrointestinal tract, CNS, bone marrow and fetal liver. Much shorter versions of NmU are found in some species, but not in human, and are derived at least in some instances from the proteolytic cleavage of the longer NmU. Despite species differences in NmU structure, the C-terminal region (particularly the C-terminal pentapeptide) is highly conserved and contains biological activity. Neuromedin S (neuromedin S-33) has also been identified as an endogenous agonist [95]. NmS-33 is, as its name suggests, a 33 amino-acid product of a precursor protein derived from a single gene and contains an amidated C-terminal heptapeptide identical to NmU. NmS-33 appears to activate NMU receptors with equivalent potency to NmU-25.

Active Transport of α-Aminoisobutyric Acid by the Isolated Midgut of Hyalophora Cecropia

1972 ◽  
Vol 56 (1) ◽  
pp. 167-172
Author(s):  
SIGNE NEDERGAARD
Keyword(s):  
Amino Acid ◽  
Active Transport ◽  
Opposite Direction ◽  
Amino Acid Transport ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Acid Transport ◽  
Active Process ◽  
Aminoisobutyric Acid ◽  
Amino Acid Flux

1. The α-aminoisobutyric acid flux from lumen to blood of the isolated Cecropia midgut is around 17 µmole/h, while the amino acid flux in the opposite direction is on average 0.3 µmole/h. 2. The amino acid uptake is inhibited by lack of oxygen. It is suggested that the amino acid transport from lumen to blood is an active process. 3. The amino acid uptake is inhibited by short-circuiting the midgut potential, indicating that there is no direct correlation between the active transport of potassium and the uptake of the amino acid by the midgut.

scholarly journals Differential effects of intrauterine growth restriction and a hypersinsulinemic-isoglycemic clamp on metabolic pathways and insulin action in the fetal liver

2019 ◽  
Vol 316 (5) ◽  
pp. R427-R440 ◽  
Author(s):  
Amanda K. Jones ◽  
Laura D. Brown ◽  
Paul J. Rozance ◽  
Natalie J. Serkova ◽  
William W. Hay ◽  
...  
Keyword(s):  
Amino Acid ◽  
Signaling Pathways ◽  
Cholesterol Synthesis ◽  
Fetal Liver ◽  
Energy State ◽  
Hepatic Glucose Production ◽  
Glucose Production ◽  
Fetal Sheep ◽  
Intrauterine Growth ◽  
Insulin Clamp

Intrauterine growth-restricted (IUGR) fetal sheep have increased hepatic glucose production (HGP) that is resistant to suppression during a hyperinsulinemic-isoglycemic clamp (insulin clamp). We hypothesized that the IUGR fetal liver would have activation of metabolic and signaling pathways that support HGP and inhibition of insulin-signaling pathways. To test this, we used transcriptomic profiling with liver samples from control (CON) and IUGR fetuses receiving saline or an insulin clamp. The IUGR liver had upregulation of genes associated with gluconeogenesis/glycolysis, transcription factor regulation, and cytokine responses and downregulation of genes associated with cholesterol synthesis, amino acid degradation, and detoxification pathways. During the insulin clamp, genes associated with cholesterol synthesis and innate immune response were upregulated in CON and IUGR. There were 20-fold more genes differentially expressed during the insulin clamp in IUGR versus CON. These genes were associated with proteasome activation and decreased amino acid and lipid catabolism. We found increased TRB3, JUN, MYC, and SGK1 expression and decreased PTPRD expression as molecular targets for increased HGP in IUGR. As candidate genes for resistance to insulin’s suppression of HGP, expression of JUN, MYC, and SGK1 increased more during the insulin clamp in CON compared with IUGR. Metabolites were measured with 1H-nuclear magnetic resonance and support increased amino acid concentrations, decreased mitochondria activity and energy state, and increased cell stress in the IUGR liver. These results demonstrate a robust response, beyond suppression of HGP, during the insulin clamp and coordinate responses in glucose, amino acid, and lipid metabolism in the IUGR fetus.

Fetal hepatic and umbilical uptakes of glucogenic substrates during a glucagon-somatostatin infusion

2002 ◽  
Vol 282 (3) ◽  
pp. E542-E550 ◽  
Author(s):  
Cecilia Teng ◽  
Frederick C. Battaglia ◽  
Giacomo Meschia ◽  
Michael R. Narkewicz ◽  
Randall B. Wilkening
Keyword(s):  
Amino Acid ◽  
Acid Metabolism ◽  
Fetal Liver ◽  
Amino Acid Uptake ◽  
Hepatic Uptake ◽  
High Rate ◽  
Acid Uptake ◽  
Glucose Carbon ◽  
Ovine Fetal ◽  
Equivalent Reduction

To test the hypothesis that fetal hepatic glutamate output diverts the products of hepatic amino acid metabolism from hepatic gluconeogenesis, ovine fetal hepatic and umbilical uptakes of glucose and glucogenic substrates were measured before and during fetal glucagon-somatostatin (GS) infusion and during the combined infusion of GS, alanine, glutamine, and arginine. Before the infusions, hepatic uptake of lactate, alanine, glutamine, arginine, and other substrates was accompanied by hepatic output of pyruvate, aspartate, serine, glutamate, and ornithine. The GS infusion induced hepatic output of 1.00 ± 0.07 mol glucose carbon/mol O2 uptake, an equivalent reduction in hepatic output of pyruvate and glutamate carbon, a decrease in umbilical glucose uptake and placental uptake of fetal glutamate, an increase in hepatic alanine and arginine clearances, and a decrease in umbilical alanine, glutamine, and arginine uptakes. The latter result suggests that glucagon inhibits umbilical amino acid uptake. We conclude that fetal hepatic pyruvate and glutamate output is part of an adaptation to placental function that requires the fetal liver to maintain both a high rate of catabolism of glucogenic substrates and a low rate of gluconeogenesis.

Comprehensive amino acid flux analysis in the post-acute phase of critically ill post-surgery patients, compared to healthy matched subjects

2020 ◽  
Vol 40 ◽  
pp. 420
Author(s):  
I.A. Bendavid ◽  
B. zribi ◽  
I. ben arye ◽  
P. singer ◽  
G. ten have ◽  
...  
Keyword(s):  
Amino Acid ◽  
Critically Ill ◽  
Acute Phase ◽  
Flux Analysis ◽  
Post Surgery ◽  
Amino Acid Flux

A novel gene, MEL1, mapped to 1p36.3 is highly homologous to the MDS1/EVI1 gene and is transcriptionally activated in t(1;3)(p36;q21)-positive leukemia cells

Blood ◽  
2000 ◽  
Vol 96 (9) ◽  
pp. 3209-3214 ◽  
Author(s):  
Naomi Mochizuki ◽  
Seiichi Shimizu ◽  
Toshiro Nagasawa ◽  
Hideo Tanaka ◽  
Masafumi Taniwaki ◽  
...  
Keyword(s):  
Amino Acid ◽  
Transcriptional Activation ◽  
Zinc Finger Protein ◽  
Fetal Liver ◽  
Amino Acid Sequences ◽  
Leukemia Cells ◽  
The Novel ◽  
Amino Acid Residues ◽  
Novel Gene ◽  
Pr Domain

The reciprocal translocation t(1;3)(p36;q21) occurs in a subset of myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML), which is frequently characterized by trilineage dysplasia, in particular dysmegakaryocytopoiesis, and poor prognosis. Previously, the breakpoint cluster region (BCR) at 3q21 was identified within a 60-kilobase (kb) region centromeric to the BCR of 3q21q26 syndrome and that at 1p36.3 within a 90-kb region. In this study, genes were searched near the breakpoints at 1p36.3, and a novel gene was isolated that encoded a zinc finger protein with a PR domain, which is highly homologous to theMDS1/EVI1 gene. The novel gene, designated asMEL1(MDS1/EVI1-like gene 1), with 1257 amino acid residues is 64% similar in nucleotide and 63% similar in amino acid sequences to MDS1/EVI1 with the same domain structure. The MEL1 gene is expressed in leukemia cells with t(1;3) but not in other cell lines or bone marrow, spleen, and fetal liver, suggesting that MEL1 is specifically in the t(1;3)(p36;q21)-positive MDS/AML. On the basis of the positional relationship between the EVI1 and MEL1 genes in each translocation, it was suggested that both genes are transcriptionally activated by the translocation of the 3q21 region with the Ribophorin I gene. Because of the transcriptional activation of the EVI1 family genes in both t(1;3)(p36;q21)-positive MDS/AML and 3q21q26 syndrome, it is suggested that they share a common molecular mechanism for the leukemogenic transformation of the cells.

Purification and structural characterization of ovine placental lactogen

1990 ◽  
Vol 126 (1) ◽  
pp. 141-149 ◽  
Author(s):  
W. C. Warren ◽  
R. Liang ◽  
G. G. Krivi ◽  
N. R. Siegel ◽  
R. V. Anthony
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Structural Characterization ◽  
Binding Sites ◽  
Untranslated Region ◽  
Fetal Liver ◽  
Radioreceptor Assay ◽  
Placental Lactogen ◽  
Predicted Amino Acid Sequence ◽  
Cdna Clones

ABSTRACT Discrepancies exist in the reported purity and biological activity of ovine placental lactogen (oPL), and little structural characterization has been reported. Ovine PL was purified from fetal cotyledonary tissue (day 100 of gestation) by monitoring activity with a recombinant bovine GH (bGH) liver radioreceptor assay. Two hundred grams of tissue yielded 4·2 mg of oPL, with an ∼ 1000-fold purification of oPL specific activity following initial tissue extraction. The oPL was radioiodinated and used in an ovine fetal liver (day 100 of gestation) radioreceptor assay to examine competitive displacement of oPL, ovine GH (oGH) and ovine prolactin (oPRL). The potency of oPL (ED50 = 0·18 nmol/l; ED50 is the quantity of ligand necessary to displace 50% of specifically bound 125I-labelled oPL) was greater than that of oGH (ED50 = 4·1 nmol/l) and oPRL (ED50 = 1·1 μmol/l) in competing for 125I-labelled oPL-binding sites. Attempts to sequence the NH2 terminus of oPL by vapour-phase sequencing indicated that the NH2 terminus was blocked. Purified oPL was subjected to trypsin and CnBr digestion, and two CnBr and six tryptic peptides were sequenced. The peptide sequences were compared with other PLs, oPRL and bGH for sequence similarity, and found to be most similar to bovine PL (bPL; 68% overall identity) and oPRL (47% overall identity). Complementary DNA (cDNA) clones were isolated for oPL by screening a λZAP cDNA library with a cDNA coding for bPL. Three cDNAs were nucleotide sequenced, and their combined sequence included 41 nucleotides of 5'-untranslated region, the complete coding region of pre-oPL (708 nucleotides) and a portion of the 3' untranslated region (158 nucleotides). The predicted amino acid sequence derived from the nucleotide sequence confirmed homology to bPL (67%) and oPRL (48%). Little amino acid sequence existed with other PLs (≤29%) or GH proteins (≤27%). These results suggest that oPL and oGH are more biologically similar in their ability to compete for fetal liver binding sites, but that oPL is structurally more similar to oPRL. Elucidation of exact structure–function relationships for oPL will, however, require further investigation. Journal of Endocrinology (1990) 126, 141–149

scholarly journals Alanine Efflux across the Serosal Border of Turtle Intestine

1972 ◽  
Vol 60 (6) ◽  
pp. 720-734 ◽  
Author(s):  
J.J. Hajjar ◽  
R.N. Khuri ◽  
Peter F. Curran
Keyword(s):  
Amino Acid ◽  
Intestinal Cells ◽  
Mucosal Cell ◽  
Transport Mechanisms ◽  
Acid Transport ◽  
Free Medium ◽  
Cell Border ◽  
Alanine Transport ◽  
Acid Extrusion ◽  
Amino Acid Flux

The exit of alanine across the serosal border of the epithelial cells of turtle intestine was measured by direct and indirect techniques. A decrease or an increase in cell Na did not affect the amino acid flux from cell to serosal solution. Cells loaded with Na and alanine did not exhibit any extrusion of alanine when their serosal membranes were exposed to an Na-free medium containing alanine. However, substantial amino acid extrusion was observed across the mucosal cell border under similar conditions. Although alanine flux across the serosal membrane appeared to be Na-independent, it showed a tendency toward saturation as cellular alanine concentration was elevated. The results are consistent with the postulate that the serosal and mucosal membranes of intestinal cells are asymmetrical with respect to amino acid transport mechanisms. The serosal membrane appears to have an Na-independent carrier-mediated mechanism responsible for alanine transport while transport across the mucosal border involves an Na-dependent process.

Characterization of the expression of the alternative splicing of the ED-A, ED-B and V regions of fibronectin mRNA in bovine ovarian follicles and corpora lutea

1999 ◽  
Vol 11 (6) ◽  
pp. 367 ◽  
Author(s):  
L. M. De Candia ◽  
R. J. Rodgers
Keyword(s):  
Alternative Splicing ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Fetal Liver ◽  
Ovarian Follicles ◽  
Corpora Lutea ◽  
Product Size ◽  
Pcr Products ◽  
Fibronectin Mrna

Fibronectin is an extracellular matrix glycoprotein. Alternative splicing of fibronectin mRNA within three specific regions, the extra domains (ED) A and B and the variable (V) or IIICS region, result in the production of different isoforms of fibronectin. These isoforms differentially regulate tissue developmental processes, such as those occurring during follicular and luteal development. The specific isoforms of fibronectin present in follicles and corpora lutea have not been identified. To identify these, primers for reverse transcription polymerase chain reaction (RT-PCR) were designed to the known bovine amino acid sequence of exons flanking the ED-A, ED-B and V regions. PCR products from bovine fetal liver cDNA were determined to be bovine fibronectin by the correct product size and DNA sequence homology to other species, and to the known bovine amino acid sequence. Bovine ovarian follicles (0.5–9 mm diameter) and corpora lutea (cyclic, early to late mid-luteal phase) were shown to express ED-A+, ED-A–, ED-B+, ED-B–, V+ and V– fibronectin isoforms, similar to the liver, lung and kidney of fetuses, but generally not of adult animals. Thus follicles and corpora lutea express isoforms of fibronectin usually expressed in developing tissues. Extra keyword: cDNA sequence.

Sign in / Sign up

Export Citation Format

Share Document