Effects of hypophysectomy and growth hormone on utilizable amino acid accumulation

1962 ◽  
Vol 203 (5) ◽  
pp. 933-938 ◽  
Author(s):  
C. A. Snipes ◽  
J. L. Kostyo
Keyword(s):  
Amino Acids ◽  
Growth Hormone ◽  
Amino Acid ◽  
Incubation Medium ◽  
Cell Water ◽  
Bicarbonate Buffer ◽  
Acid Accumulation ◽  
Hypophysectomized Rats ◽  
Amino Acid Accumulation

Hypophysectomy decreased the concentrations of alanine and histidine in the cell water of the rat diaphragm, but had no influence on the levels of these amino acids in plasma. The concentrations of alanine and histidine in the cell water did not vary appreciably from in vivo values, when "intact" diaphragms of either normal or hypophysectomized rats were incubated in Krebs bicarbonate buffer. Addition of l-alanine or l-histidine to the incubation medium resulted in the accumulation of these amino acids in the cell water of both normal and hypophysectomized rat diaphragms. However, muscles or hypophysectomized rats accumulated these amino acids to a lesser extent. When added to the incubation medium, bovine growth hormone stimulated the accumulation of l-alanine and l-histidine by diaphragms of hypophysectomized rats. Thus, these experiments suggest that growth hormone participates in the regulation of utilizable amino acid transport into muscle.

Reduced and S-carboxymethylated human growth hormone: a probe for diabetogenic action

1984 ◽  
Vol 247 (5) ◽  
pp. E639-E644
Author(s):  
C. M. Cameron ◽  
J. L. Kostyo ◽  
J. A. Rillema ◽  
S. E. Gennick
Keyword(s):  
Growth Hormone ◽  
Amino Acid ◽  
Human Growth Hormone ◽  
Human Growth ◽  
Mouse Mammary Gland ◽  
Amino Acid Incorporation ◽  
Acid Incorporation ◽  
Hypophysectomized Rats

The biological activity profile of reduced and S-carboxymethylated human growth hormone (RCM-hGH) was determined to establish its suitability for study of the diabetogenic property of hGH. RCM-hGH was found to have greatly attenuated in vivo growth-promoting activity in the 9-day weight-gain test in hypophysectomized rats (approximately 1%) and to have a similar low order of in vitro activity in stimulating amino acid incorporation into the protein of the isolated rat diaphragm. RCM-hGH also only had approximately 1% of the in vitro insulin-like activity of the native hormone on isolated adipose tissue from hypophysectomized rats. In contrast, RCM-hGH retained substantial in vivo diabetogenic activity in the ob/ob mouse, appearing to have approximately 50% of the activity of the native hormone. RCM-hGH was also found to retain significant, although attenuated (25%), in vitro lactogenic activity when tested for the ability to stimulate amino acid incorporation into a casein-rich protein fraction in mouse mammary gland explants. Because RCM-hGH exhibits a high degree of diabetogenic activity, although lacking significant anabolic or insulin-like activities, it will be useful as a "monovalent" probe for the study of the molecular mechanism of the diabetogenic action of GH.

scholarly journals Action of insulin and growth hormone on protein synthesis in muscle from non-hypophysectomized rabbits

1971 ◽  
Vol 125 (2) ◽  
pp. 515-520 ◽  
Author(s):  
P. J. Reeds ◽  
K. A. Munday ◽  
M. R. Turner
Keyword(s):  
Amino Acids ◽  
Growth Hormone ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Incubation Medium ◽  
Amino Acid Uptake ◽  
Diaphragm Muscle ◽  
Acid Uptake

The separate effects of insulin and growth hormone on the uptake and incorporation of five amino acids into diaphragm muscle from non-hypophysectomized rabbits has been examined. Both growth hormone and insulin, when present in the medium separately, stimulated the incorporation into protein of the amino acids, leucine, arginine, valine, lysine and histidine. Insulin also stimulated amino acid uptake, but growth hormone did not. When insulin and growth hormone were present in the incubation medium together, the uptake and incorporation of valine, the only amino acid studied under these conditions, tended to be greater than the sum of the separate effects of the two hormones.

scholarly journals Amino acid requirement for the growth-hormone stimulation of incorporation of precursors into protein and nucleic acids of liver slices

1970 ◽  
Vol 119 (4) ◽  
pp. 629-634 ◽  
Author(s):  
M. J. Clemens ◽  
A. Korner
Keyword(s):  
Amino Acids ◽  
Growth Hormone ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Mechanism Of Action ◽  
Plasma Concentrations ◽  
Liver Slices ◽  
Hypophysectomized Rats ◽  
Stimulation Of

1. Incorporation of [14C]leucine into protein in rat liver slices, incubated in vitro, increased as the concentration of unlabelled amino acids in the incubation medium was raised. A plateau of incorporation was reached when the amino acid concentration was 6 times that present in rat plasma. Labelling of RNA by [3H]orotic acid was not stimulated by increased amino acid concentration in the incubation medium. 2. When amino acids were absent from the medium, or present at the normal plasma concentrations, no effect of added growth hormone on labelling of protein or RNA by precursor was observed. 3. When amino acids were present in the medium at 6 times the normal plasma concentrations addition of growth hormone stimulated incorporation of the appropriate labelled precursor into protein of liver slices from normal rats by 31%, and into RNA by 22%. A significant effect was seen at a hormone concentration as low as 10ng/ml. 4. Under the same conditions addition of growth hormone also stimulated protein labelling in liver slices from hypophysectomized rats. Tissue from hypophysectomized rats previously treated with growth hormone did not respond to growth hormone in vitro. 5. No effect of the hormone on the rate or extent of uptake of radioactive precursors into acid-soluble pools was found. 6. Cycloheximide completely abolished the hormone-induced increment in labelling of both RNA and protein. 7. It was concluded that, in the presence of an abundant amino acid supply, growth hormone can stimulate the synthesis of protein in rat liver slices by a mechanism that is more sensitive to cycloheximide than is the basal protein synthesis. The stimulation of RNA labelling observed in the presence of growth hormone may be a secondary consequence of the hormonal effect on protein synthesis. 8. The mechanism of action of growth hormone on liver protein synthesis in vitro was concluded to be similar to its mechanism of action in vivo.

scholarly journals Amino Acid Accumulation by Human Reticulocytes

Blood ◽  
1960 ◽  
Vol 16 (5) ◽  
pp. 1564-1571 ◽  
Author(s):  
DAVID W. ALLEN
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Ion Exchange ◽  
Concentration Ratio ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Red Cells ◽  
Red Cell ◽  
Acid Accumulation ◽  
Amino Acid Accumulation

Abstract 1. The concentrations of certain amino acids were measured by ion exchange chromatography in mature red cells, in red cells with a high percentage of reticulocytes, and in the plasma in which these red cells had been suspended. The concentration ratio as a measure of net accumulation of the red cells for amino acids was derived from these data. 2. Adult red cells can accumulate glycine and alanine, but not methionine, valine, isoleucine or leucine. 3. Reticulocytes can accumulate glycine best, then alanine, then methionine, isoleucine, and leucine to approximately the same extent. They were unable to maintain a concentration gradient for valine. 4. In two patients with thalassemia, no abnormality was found in the plasma or red cell levels of citrulline, proline, glycine, alanine, valine, isoleucine, tyrosine, or phenylalanine. In one of the thalassemic patients no abnormality of histidine was found. The amino acid accumulation by thalassemic, or fetal red cells was the same as for normal red cells of comparable reticulocyte percentage.

scholarly journals Nutritional aspects of amino acid metabolism

1971 ◽  
Vol 26 (3) ◽  
pp. 393-422 ◽  
Author(s):  
D. L. Bloxam
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glucose Production ◽  
Inhibitory Effect ◽  
Bile Secretion ◽  
Bicarbonate Buffer ◽  
Satisfactory Condition ◽  
Extrahepatic Tissues ◽  
Glucose Output

1. Experiments were done to find whether the rat liver can be maintained in a satisfactory condition when perfused with oxygenated Krebs-Ringer bicarbonate buffer without added protein or red cells.2. The condition and preformance of the liver in this system were assessed from measurements made to ascertain its general condition or viability, its basal characteristics and its response to added substrates.3. It was found that the rapid flow-rate of the medium through the livers and the efficient oxygenation of the medium ensured that enough oxygen was available for the livers to deal with large quantities of added lactate.4. The potassium concentrations in the livers and the rates of alanine aminotransferase (EC 2.6.1.6) from the cells during perfusion, and the water content after perfusion showed that the livers were not grossly damaged and that they did not deteriorate measurably for up to 3 h of perfusion.5. Liver oxygen consumption, ATP concentrations, lactate and pyruvate concentrations and ratios, and rates of urea and glucose synthesis and bile secretion, all in perfusions without added substrate, were either similar to measurements by other workers from livers perfused withmedia containingred cells and protein or were reasonable extrapolations from availabledata.6. The rates of glucose production from lactate, and urea and glucose output from amino acids indicated that the liver responds adequately to added substrates.7. Measurements of amino acid concentrations in perfusate indicated that the livers of rats starved for 18–20 h regulated the amino acids to characteristic levels, by overall output or uptake, except for valine, leucine and isoleucine which were continuously given out into the medium. The results suggest that in vivo there is a general flow of most of the amino acids from extrahepatic tissues to the liver during fasting, while valine, leucine and isoleucine flow from liver to extrahepatic tissues.8. When pentobarbitone sodium (Nembutal) was used as the anaesthetic for removal of the liver from the donor rat, the rates of urea and glucose output in perfusions without added substrates were lower than when halothane (Fluothane) was used, indicating that pentobarbitone has an inhibitory effect on these measures of liver function during the subsequent perfusion.

scholarly journals Regulation of Glutamate Dehydrogenases in Neurospora Crassa as a Response to Carbohydrates and Amino Acids in the Media

1971 ◽  
Vol 24 (4) ◽  
pp. 905 ◽  
Author(s):  
WN Strickland
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Sole Carbon Source ◽  
Nitrogen Sources ◽  
Carbon And Nitrogen Sources ◽  
Carbon And Nitrogen ◽  
Acid Accumulation ◽  
The Media ◽  
Amino Acid Concentrations ◽  
Amino Acid Accumulation

Mycelial pads of N. crassa grown for 48 hr in minimal medium were harvested, washed, and transferred to test media containing a variety of carbon and nitrogen sources. When some amino acids served as the sole carbon source, NAD-GDH was induced and the activity of NADP-GDH declined. Addition of sucrose depressed or prevented induction of NAD-GDH while NADP�GDH activity was maintained. Internal amino acid concentrations increased when mycelial pads were incubated in amino acids that induced NAD-GDH, but these accumulated amino acids were only oxidized in the absence of sucrose. The rate of amino acid accumulation decreased if sucrose was present in the media.

scholarly journals The control by insulin of amino acid accumulation in muscle

1970 ◽  
Vol 117 (3) ◽  
pp. 457-465 ◽  
Author(s):  
K. L. Manchester
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Aminobutyric Acid ◽  
Technical Problems ◽  
Protein Uptake ◽  
Cell Pool ◽  
Acid Accumulation ◽  
Amino Acid Accumulation ◽  
Stimulation Of

1. The capacity of insulin to enhance the accumulation by muscle of several amino acids was studied. Reports that threonine uptake is enhanced by insulin were not confirmed, despite its enhanced incorporation into protein. Uptake of β-alanine and γ-aminobutyric acid also did not respond to the hormone. A stimulation of accumulation of alanine, histidine and ethionine was observed. 2. The capacity of inhibitors of protein synthesis to reveal a stimulation by insulin of accumulation of several amino acids, hitherto considered unresponsive to insulin in the absence of inhibitor, was confirmed. Cycloheximide was as effective as puromycin. However, two of these amino acids, alanine and histidine, here showed response to insulin in the absence of inhibitor. The presence of cycloheximide was found to enhance uptake of cycloleucine, ethionine and threonine; in its presence insulin enhanced uptake of β-alanine and α-methyltyrosine. 3. It is concluded that the influence of inhibitors of protein synthesis on amino acid accumulation and the response of amino acid accumulation to insulin are not adequately explained on the basis of inhibition of protein synthesis allowing amino acids to accumulate more readily. 4. The technical problems of whether linear rates of incorporation of amino acids into protein really indicate more than one cell pool are discussed and safeguards suggested. That initial rates of incorporation of label into protein are likely to be non-linear is shown.

TEMPORAL RELATIONSHIP OF THE GROWTH HORMONE EFFECTS ON AMINO ACID TRANSPORT AND PROTEIN SYNTHESIS IN ISOLATED RAT DIAPHRAGM

1968 ◽  
Vol 57 (3_Suppl) ◽  
pp. S37-S48 ◽  
Author(s):  
Å. Hjalmarson
Keyword(s):  
Amino Acids ◽  
Growth Hormone ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Distribution Ratio ◽  
Rat Diaphragm ◽  
Acid Transport ◽  
Hypophysectomized Rats ◽  
Isolated Rat

ABSTRACT Experiments were performed to study whether the influence of bovine growth hormone (GH) on the mebrane transport of labelled leucine and glycine in the isolated rat diaphragm was similar to that previously found for α-aminoisobutyric acid (Hjalmarson & Abrén 1967a, b). The relationship between the effects of GH on amino acid transport and protein synthesis was also studied. Addition of GH in vitro (25 μg/ml) to intact hemidiaphragms from hypophysectomized rats increased the accumulation of glycine in the intracellular water after 2 hours of incubation, while that of leucine was reduced. GH in vitro increased the incorporation rate into muscle protein of both glycine and leucine. An Intravenous (i. v.) injection of GH (10 μg) to hypophysectomized rats 60 min. before incubation increased the distribution ratio of leucine, while no significant effect was found on the incorporation into protein of this amino acid. On the other hand, an injection of GH (10 μg) 180 min. before incubation increased the in vitro incorporation of both leucine and glycine. This injection did not change the distribution ratio of glycine and that of leucine was significantly decreased. Repeated injections of GH (50 μg × 4 days) increased the incorporation of both glycine and leucine. This treatment also increased the accumulation of glycine after 2 hours of incubation, while no such effect was seen on the accumulation of leucine. In vitro addition of GH (25 μg/ml) did not significantly change the distribution ratio of glycine and leucine in diaphragms from hypophysectomized rats previously treated with GH. However, addition of GH in vitro to the diaphragms from these rats further increased the incorporation of glycine into protein. In addition, GH in vitro increased the accumulation of glycine also when the incorporation of this amino acid into protein was completely blocked by puromycin (500 μg/ml). The present results show that GH, at least in certain doses, may have a biphasic action on the membrane transport of normal amino acids. The results also indicate that GH may have separate effects on the membrane transport and the incorporation into protein of amino acids.

scholarly journals Primary structure requirements for correct sorting of the yeast mitochondrial protein ADH III to the yeast mitochondrial matrix space.

1987 ◽  
Vol 7 (1) ◽  
pp. 294-304 ◽  
Author(s):  
D Pilgrim ◽  
E T Young
Keyword(s):  
Amino Acids ◽  
Enzyme Activity ◽  
Amino Acid ◽  
Proteolytic Processing ◽  
Mitochondrial Matrix ◽  
Wild Type ◽  
Mature Form ◽  
Amino Terminal ◽  
The Matrix

Alcohol dehydrogenase isoenzyme III (ADH III) in Saccharomyces cerevisiae, the product of the ADH3 gene, is located in the mitochondrial matrix. The ADH III protein was synthesized as a larger precursor in vitro when the gene was transcribed with the SP6 promoter and translated with a reticulocyte lysate. A precursor of the same size was detected when radioactively pulse-labeled proteins were immunoprecipitated with anti-ADH antibody. This precursor was rapidly processed to the mature form in vivo with a half-time of less than 3 min. The processing was blocked if the mitochondria were uncoupled with carbonyl cyanide m-chlorophenylhydrazone. Mutant enzymes in which only the amino-terminal 14 or 16 amino acids of the presequence were retained were correctly targeted and imported into the matrix. A mutant enzyme that was missing the amino-terminal 17 amino acids of the presequence produced an active enzyme, but the majority of the enzyme activity remained in the cytoplasmic compartment on cellular fractionation. Random amino acid changes were produced in the wild-type presequence by bisulfite mutagenesis of the ADH3 gene. The resulting ADH III protein was targeted to the mitochondria and imported into the matrix in all of the mutants tested, as judged by enzyme activity. Mutants containing amino acid changes in the carboxyl-proximal half of the ADH3 presequence were imported and processed to the mature form at a slower rate than the wild type, as judged by pulse-chase studies in vivo. The unprocessed precursor appeared to be unstable in vivo. It was concluded that only a small portion of the presequence contains the necessary information for correct targeting and import. Furthermore, the information for correct proteolytic processing of the presequence appears to be distinct from the targeting information and may involve secondary structure information in the presequence.

Sign in / Sign up

Export Citation Format

Share Document