Amino acids enhance renal tubular absorption of the los-molecular-weight proteins insulin and growth hormone

1982 ◽  
Vol 242 (6) ◽  
pp. F745-F749
Author(s):  
R. Rabkin ◽  
T. I. Gottheiner ◽  
T. S. Tsao
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Growth Hormone ◽  
Human Growth ◽  
Metabolic Effect ◽  
Low Molecular Weight ◽  
Insulin Absorption ◽  
Tubular Absorption ◽  
Renal Tubular ◽  
Isolated Rat

The effect of amino acids(AA) on the tubular absorption of low-molecular-weight (LMW) proteins was studied in isolated rat kidneys. Kidneys were perfused with an albumin-electrolyte solution that contained insulin or human growth hormone (hGH) and, unless otherwise stated, the following L-amino acids: glycine, isoleucine, serine, alanine, methionine, proline, arginine, and aspartic acid. In kidneys perfused without AA, fractional urinary insulin clearance (FCi) averaged 7.4 +/- 1.54%, whereas in the presence of multiple AA the FCi was significantly lower (0.68 +/- 0.2%, P less than 0.01). Addition of glycine or alpha-aminoisobutyric acid (AIB) alone also reduced the FCi significantly (1.79 +/- 0.66 and 1.59 +/-1.06%, respectively). By contrast, perfusion with the other AA individually did not alter the FCi. The fractional urinary hGH clearance was also significantly lower in kidneys perfused with multiple AA (0.94 +/- 0.47%) than in those perfused without AA (9.07 +/- 1.2%). We conclude that tubular absorption of filtered insulin and hGH is enhanced by the presence of AA. The mechanism is unclear, but enhancement of insulin absorption can be produced by glycine and AIB alone. This raises the possibility of a link between the absorption of insulin and the glycine and AIB shared transport system, but excludes a primary metabolic effect because AIB is nonmetabolizable.

Difunctional enols of N-protected amino acids as low molecular weight and novel inhibitors of HIV-1 protease.

1993 ◽  
Vol 3 (6) ◽  
pp. 1169-1174 ◽  
Author(s):  
Marc Vaillancourt ◽  
Benoit Vanasse ◽  
Eric Cohen ◽  
Gilles Sauv
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Low Molecular Weight ◽  
Hiv 1

GROWTH HORMONE

PEDIATRICS ◽  
1965 ◽  
Vol 36 (6) ◽  
pp. 940-950
Author(s):  
Allen Root
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Growth Hormone ◽  
Mineral Metabolism ◽  
Acquired Resistance ◽  
Nitrogen Retention ◽  
Human Growth ◽  
Acid Synthesis ◽  
Term Administration ◽  
Fat Stores

Growth hormone influences protein, fat, carbohydrate, and mineral metabolism. It promotes nitrogen retention, growth of cartilage, transportation of amino acids through the cell wall, and incorporation of amino acids into protein. This factor mobilizes free fatty acids from adipose tissue and increases the serum concentration of these substances; long-term administration of this hormone is followed by depletion of body fat stores and inhibition of fatty acid synthesis. In diabetic subjects growth hormone administration is followed by hyperglycemia, glycosuria, and ketosis; its effect on carbohydrate metabolism in normal subjcets is more subtle. Sodium, potassium, and inorganic phosphate are retained following the administration of growth hormone. Hypercalciuria also accompanies such treatment, an effect mediated through the parathyroid glands. Human growth hormone may be detected in the serum through the use of the radioimmunoassay. The hypothalamus is intimately involved with the control of the secretion and release of growth hormone from the pituitary. There is a correlation between the availability of glucose for metabolism and the plasma concentration of growth hormone; when glucose is unavailable growth hormone is released in order to provide a substitute source of energy, fatty acids. The administration of growth hormone to the patient with hypopituitarism is followed by growth in many instances, but it has not usually been effective in promoting growth in individuals with other abnormalities. Acquired resistance to the effect of growth hormone is accompanied by the development of antibodies directed against this protein.

Localization of heparin and low-molecular-weight heparin in the rat kidney

2004 ◽  
Vol 91 (05) ◽  
pp. 927-934 ◽  
Author(s):  
Vivian Douros ◽  
Thomas Podor ◽  
Stephen Shaughnessy ◽  
Jeffrey Weitz ◽  
Edward Young
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Rat Kidney ◽  
Organic Anion ◽  
Molecular Size ◽  
Immunohistochemical Analysis ◽  
Immunoperoxidase Staining ◽  
Low Molecular Weight ◽  
Renal Tubular Cells ◽  
Renal Tubular

SummaryUnfractionated heparin (UFH) and low-molecular-weight heparin (LMWH) are cleared, at least in part, by the kidneys through a poorly understood process. This study was undertaken to explore the mechanism of renal clearance of these drugs. Rats were given fluorescein-5-isothiocyanate (FITC)-labeled UFH or LMWH intravenously. At intervals after injection, rats were euthanized and the kidneys were harvested and subjected to immunohistochemical analysis and fluorescence microscopy. Both UFH and LMWH were localized to renal tubular cells and no immunoperoxidase staining or fluorescence was detected in glomeruli. Autoradiography demonstrated similar intracellular distribution of radio-labeled UFH suggesting that this phenomenon is independent of the method used to label heparin. Fluoresence in the tubules increased as a function of time after UFH injection, but reached a plateau after LMWH injection suggesting that the rate of renal tubular uptake depends on the molecular size of the heparin. When administered prior to FITC-labeled UFH or LMWH, probenecid, a renal organic anion inhibitor, decreased the renal tubular uptake of the heparins, whereas cimetidine, a renal organic cation inhibitor, had no effect. These findings suggest that renal excretion of UFH and LMWH primarily reflects tubular uptake via an organic anion transport mechanism.

Effects of glycosylation inhibitors on human growth hormone receptor in cultured human lymphocytes

1988 ◽  
Vol 119 (4) ◽  
pp. 517-524 ◽  
Author(s):  
Kumiko Asakawa ◽  
Jose A. Hedo ◽  
Phillip Gorden ◽  
Kazuo Shizume
Keyword(s):  
Molecular Weight ◽  
Growth Hormone ◽  
Human Growth Hormone ◽  
Growth Hormone Receptor ◽  
Human Lymphocytes ◽  
Human Growth ◽  
Control Value ◽  
Receptor Complexes ◽  
Oligosaccharide Processing ◽  
Receptor Number

Abstract. IM-9 cultured human lymphocytes were treated with N-linked glycosylation inhibitors, N-linked oligosaccharide processing inhibitors, or neuraminidase to study the effect of glycosylation modification on human growth hormone binding and molecular weight of surface hGH receptor. One mg/l tunicamycin and 20 mmol/l glucosamine decreased 125I-hGH binding to the cells to 46.3 ± 2.4% (mean ± sem) and 21.9 ± 0.2% of the controls, respectively. The hGH binding was 33.0 ± 18.4% of the control value in the cells treated with monensin. The inhibition of binding was due to a decrease in the hGH receptor number without any affinity changes in these cells. Neither 1 mg/l swainsonine nor 100 mg/l castanospermine had any effect on the hGH binding. On the other hand, 125I-hGH binding to neuraminidase-treated cells was significantly enhanced with accompanying affinity changes. When 125I-hGH was cross-linked to IM-9 cells, there were no differences in the molecular weight of hGH receptor complexes (140K) between untreated cells and cells treated with tunicamycin, glucosamine, monensin, or castanospermine. However, the 128K hGH-receptor complex appeared in swainsonine-treated cells; this complex was sensitive to endoglycosidase H. These data show that the altered carbohydrate moiety changed hGH binding and the size of surface hGH receptor and suggest that glycosylation of receptor is important for the binding of hGH and for its physiological action.

EFFECTIVENESS AND SAFENESS OF LOW MOLECULAR WEIGHT HEPARINS APPLICATION IN CHILDREN WITH RIGHT ATRIUM THROMBOSES

2018 ◽  
Author(s):  
П.А. Жарков ◽  
Н.М. Ершов ◽  
А.В. Пшонкин
Keyword(s):  
Molecular Weight ◽  
Major Bleeding ◽  
Right Atrium ◽  
Malignant Disease ◽  
Final Analysis ◽  
Low Molecular Weight ◽  
Low Molecular Weight Heparins ◽  
Complete Lysis ◽  
Electronic Hospital ◽  
Isolated Rat

Введение. Тромбозы правого предсердия (ТПП) являются редкой патологией, которая чаще встречается среди новорожденных и детей, перенесших кардиохирургическое вмешательство. Истинная распространенность, а также подходы к лечению ТПП у детей, получающих терапию по поводу злокачественного заболевания, неизвестны. Цель работы: оценить распространенность ТПП, а также эффективность и безопасность применения низкомолекулярного гепарина (НМГ) у детей с ТПП. Материалы и методы. Проведен анализ электронной базы данных пациентов в возрасте 0-17 лет. Для оценки динамики размеров тромбов в анализ были включены только пациенты с объективно подтвержденным ТПП, у которых имелось не менее двух эхокардиографических исследований, и которым проводилась терапия НМГ. Оценка случаев кровотечений и тромбоэмболии легочной артерии/артерий (ТЭЛА) проводилась по записям в историях болезни пациентов. Результаты. Изолированный ТПП или ТПП в комбинации с тромбозами других локализаций был диагностирован у 13,7%, изолированный ТПП – лишь у 5% детей. При проведении антикоагулянтной терапии НМГ отсутствие динамики со стороны размеров тромба наблюдалось в 1 случае, нарастание размеров тромба – в 1 случае, уменьшение размеров тромба или полный лизис – в 13 случаях. За период наблюдения не было выявлено ни одного случая крупных кровотечений и ТЭЛА. Заключение. ТПП встречаются в 13,7% случаев среди пациентов с тромбозом. Мы считаем применение НМГ эффективным и безопасным методом вторичной антитромботической профилактики у детей с ТПП. Introduction. Right atrium thromboses (RAT) are rare pathology which is more specific for neonates and children undergoing cardiac surgery. True RAT prevalence as well as approaches to its treatment in children receiving therapy for malignant disease are unknown. Aim: to assess RAT prevalence as well as effectiveness and safeness of low molecular weight heparin (LMWH) application in children with RAT. Materials and methods. Electronic hospital database analysis was performed to find patients with objectively confirmed RAT. Children aged 0-17 years old with two or more echocardiographic examinations who received LMWH were included in final analysis. Thrombus size dynamics, the rate of pulmonary embolism (PE) and major bleeding served as effectiveness and safeness endpoints. Results. Isolated RAT or RAT in combination with thromboses of other localizations was found in 13,7%, isolated RAT – only in 5% of children. Under anticoagulant therapy with LMWH we found no dynamics in clot size – in 1 case, clot size increasing – in 1 case, reduction of clot size or its complete lysis – in 13 cases. There were no cases of major bleeding and PE during LMWH treatment. Conclusion. RAT occurs in 13,7% of cases among patients with thrombosis. We consider LMWH treatment to be effective and safe method of secondary antithrombotic prophylaxis in children with RAT.

Diabetogenic activity of native and biosynthetic human growth hormone in obese (ob/ob) mouse

1984 ◽  
Vol 246 (4) ◽  
pp. E356-E360
Author(s):  
J. L. Kostyo ◽  
S. E. Gennick ◽  
S. E. Sauder
Keyword(s):  
Growth Hormone ◽  
Glucose Intolerance ◽  
Chronic Exposure ◽  
Degradation Products ◽  
Deae Cellulose ◽  
Human Growth ◽  
Intrinsic Property ◽  
Low Molecular Weight ◽  
Pituitary Growth Hormone ◽  
Subcutaneous Dose

It has been repeatedly suggested that diabetogenic activity is not an intrinsic property of native pituitary growth hormone (GH) and that the diabetogenic effects produced by GH preparations are due to low-molecular-weight contaminants or degradation products of the hormone. This possibility was evaluated in this study by assessing the ability of purified native human GH (hGH) and biosynthetic methionyl-hGH to exacerbate fasting hyperglycemia and glucose intolerance in the obese (ob/ob) mouse. Native hGH that had been purified by DEAE-cellulose chromatography (A-type; 1.8 IU/mg) produced fasting hyperglycemia and glucose intolerance in the ob/ob mouse when injected subcutaneously at doses of 50 micrograms/day or greater for 3 days. It had no effect when a single subcutaneous dose of 200 micrograms was administered 24 h previously. To eliminate possible contamination with smaller peptides, the hGH was gel-filtered on a column of Sephacryl S-200 in 6 M guanidine-HCl. When injected subcutaneously into ob/ob mice at a dose of 50 micrograms/day or greater for 3 days, the guanidine-treated hGH produced glucose intolerance. Also biosynthetic methionyl-hGH produced marked fasting hyperglycemia and glucose intolerance when injected subcutaneously at doses of 50 or 100 micrograms/day for 3 days. These results support the conclusion that hGH itself is indeed diabetogenic but that chronic exposure of the organism to the hormone is required for its effects on glucose metabolism to become clearly manifest.

Conversion of Radiolabeled Human Growth Hormone into Higher Molecular Weight Moieties in Human Plasmain Vivoandin Vitro

Endocrinology ◽  
1977 ◽  
Vol 101 (2) ◽  
pp. 350-359 ◽  
Author(s):  
INESE Z. BEITINS ◽  
MARIO C. RATTAZZI ◽  
MARGARET H. MACGILLIVRAY
Keyword(s):  
Molecular Weight ◽  
Growth Hormone ◽  
Human Growth Hormone ◽  
Human Growth

STUDIES ON THE ISOLATION AND NATURE OF THE 'TERREGENS FACTOR'

1954 ◽  
Vol 32 (1) ◽  
pp. 400-406 ◽  
Author(s):  
M. O. Burton ◽  
F. J. Sowden ◽  
A. G. Lochhead
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Ferric Iron ◽  
Test Organism ◽  
The Other ◽  
Inorganic Salts ◽  
Low Molecular Weight ◽  
Straight Chain ◽  
Heat Stable ◽  
Growth Promoting

A procedure is described for the production and concentration of the 'terregens factor' (TF), a bacterial growth promoting substance synthesized by Arthrobacter pascens and essential for the growth of Arthrobacter terregens. From culture filtrates of A. pascens cultivated in a medium of inorganic salts and sucrose, concentrates of TF may be obtained that are active at 0.001 μgm. Per ml., heat stable and contain about 12.7% nitrogen. Acid hydrolysis yielded a number of amino acids, including glutamic acid, glycine, α–alanine, valine, leucine, proline, lysine, and arginine, as well as some unidentified compounds; however, TF does not appear to be a low molecular weight straight chain peptide.Although TF contains no iron, it combines readily with ferrous or ferric iron to form reddish-brown complexes with this metal. Activity for A. terregens is shown by certain iron containing complexes as hemin, coprogen, and ferrichrome. On the other hand none is shown by cytochrome or pulcherrimin; however, aspergillic acid, structurally related to the latter, possesses some growth promoting activity for the test organism.

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