Regulatory influence of relaxin on human cervical and uterine connective tissue

1984 ◽  
Vol 106 (1) ◽  
pp. 127-132 ◽  
Author(s):  
Ingrid Wiqvist ◽  
Anders Norström ◽  
Elizabeth O'Byrne ◽  
Nils Wiqvist
Keyword(s):  
Amino Acid Uptake ◽  
Inhibitory Effect ◽  
Lower Uterine Segment ◽  
Prostaglandin E ◽  
Similar Response ◽  
Acid Uptake ◽  
Experimental Conditions ◽  
Inverse Effect ◽  
Proline Incorporation

Abstract. Cervical tissue was obtained from women undergoing legal abortion in the 7th–15th week of gestation and tissue from the lower uterine segment was excised at elective Casearean section in the 38th–40th week. The specimens were incubated with [3H]proline in the presence of relaxin or prostaglandin E2 (PGE2). Relaxin had a concentration related inhibitory effect on the radiolabelling in the 7th–9th week but failed to influence the amino acid uptake in the 10th–15th week of pregnancy. PGE2 had the inverse effect, i.e. no influence in the former group but reduced incorporation of proline in the latter group of patients. Incubation of tissue from the lower uterine segment showed a similar response as that of the early pregnant cervix. It is concluded that relaxin has a significant influence on [3H]proline incorporation by cervical and uterine tissue under in vitro experimental conditions.

scholarly journals Amino acid uptake in the developing chick embryo heart. The effect of insulin on glycine and leucine accumulation

1968 ◽  
Vol 107 (4) ◽  
pp. 575-580 ◽  
Author(s):  
G. G. Guidotti ◽  
G. Gaja ◽  
L. Loreti ◽  
G. Ragnotti ◽  
D. A. Rottenberg ◽  
...  
Keyword(s):  
Amino Acid ◽  
Chick Embryo ◽  
Concentration Ratio ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Experimental Conditions ◽  
Insulin Effect ◽  
Chick Embryo Heart ◽  
Embryo Heart

1. The accumulation of [1−14C]glycine and the uptake, accumulation, incorporation (into protein, lipid, glycogen) and oxidation of l-[1−14C]leucine in 5-day-old chick embryo hearts were investigated in vitro, and the effects of insulin, puromycin and 4-methyl-2-oxopentanoic acid on these processes were studied. 2. With glycine, the ratio of concentration of the labelled amino acid in the cell water to that in medium markedly exceeded unity. Insulin significantly increased this ratio. Puromycin did not prevent the insulin effect. 3. With leucine, the concentration ratio of the labelled amino acid between intracellular and extracellular water approached unity in the absence of puromycin and was doubled by its presence. In neither case did insulin substantially alter this ratio. The addition of 4-methyl-2-oxopentanoic acid had no effect in the absence of insulin, but produced a significant increase of the concentration ratio in the presence of the hormone. 4. Leucine uptake was increased slightly by insulin in all experimental conditions except in the presence of puromycin, where a more pronounced stimulation was observed. The hormone had no effect on the incorporation of the labelled amino acid into protein, but accelerated its oxidation to carbon dioxide; the latter effect was particularly evident in the presence of puromycin and disappeared after the addition of 4-methyl-2-oxopentanoic acid.

Effects of oxytocin on cervical and uterine connective tissue

1984 ◽  
Vol 106 (2) ◽  
pp. 271-276 ◽  
Author(s):  
Ingrid Wiqvist ◽  
Anders Norström ◽  
Nils Wiqvist
Keyword(s):  
Connective Tissue ◽  
Pregnant Women ◽  
Inhibitory Effect ◽  
Lower Uterine Segment ◽  
Collagen Metabolism ◽  
Clinical Experiences ◽  
Experimental Conditions ◽  
Tissue Metabolism ◽  
Connective Tissue Metabolism

Abstract. The effect of oxytocin on collagen metabolism in the cervix and lower uterine segment of pregnant women was studied by measuring the incorporation of [3H]proline in vitro. Oxytocin had a concentration related inhibitory effect on the labelling with [3H]proline. Addition of indomethacin did not influence the response to oxytocin indicating that the effect was not directly mediated by prostaglandins. Oestradiol-17β potentiated the effect of oxytocin. Vasopressin decreased the incorporation of [3H]proline slightly but the action of this hormone was significantly less than that of oxytocin. The results suggest that oxytocin under in vitro experimental conditions influences cervical connective tissue metabolism which is in contrast to current clinical experiences.

Somatostatin inhibits insulin-stimulated amino acid uptake into cultured rat myoblasts

1987 ◽  
Vol 114 (4) ◽  
pp. 470-474 ◽  
Author(s):  
G. S. G. Spencer ◽  
D. J. Hill ◽  
G. J. Garssen ◽  
J. P. G. Williams
Keyword(s):  
Amino Acid ◽  
Nutrient Uptake ◽  
Monolayer Culture ◽  
Amino Acid Uptake ◽  
Inhibitory Effect ◽  
Isobutyric Acid ◽  
Acid Uptake ◽  
Newborn Rat ◽  
Amino Isobutyric Acid

Abstract. The effects of somatostatin on the acute metabolic actions of insulin on newborn rat myoblasts in culture has been examined during monolayer culture. Somatostatin significantly inhibited the insulin-stimulated uptake of [3H]leucine and [3H]amino-isobutyric acid into myoblasts but had no effect on basal (unstimulated) uptake of these two substances. The lowest concentration of somatostatin to have a significant effect was 10 μg/l, and this was apparent in all the experiments undertaken. The inhibitory effect of somatostatin was seen at all effective concentrations of insulin used (0.3–1 U/l). These findings lend support to the concept of an endocrine role for somatostatin in vivo and suggest that a peripheral antagonism may exist between circulating insulin and somatostatin on anabolic processes such as nutrient uptake into cells.

The mechanisms of amino acid uptake byBrugia pahangi in vitro

1983 ◽  
Vol 69 (2) ◽  
pp. 247-253 ◽  
Author(s):  
R. E. Howells ◽  
A. M. Mendis ◽  
P. G. Bray
Keyword(s):  
Amino Acid ◽  
Amino Acid Uptake ◽  
Acid Uptake

scholarly journals Action of growth hormone in vitro on the net uptake and incorporation into protein of amino acids in muscle from intact rabbits given protein-deficient diets

1976 ◽  
Vol 35 (1) ◽  
pp. 1-10 ◽  
Author(s):  
M. R. Turner ◽  
P. J. Reeds ◽  
K. A. Munday
Keyword(s):  
Amino Acids ◽  
Growth Hormone ◽  
Protein Synthesis ◽  
Amino Acid ◽  
De Novo ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Amino Acid Incorporation ◽  
Acid Incorporation

1. Net amino acid uptake, and incorporation into protein have been measured in vitro in the presence and absence of porcine growth hormone (GH) in muscle from intact rabbits fed for 5 d on low-protein (LP), protein-free (PF) or control diets.2. In muscle from control and LP animals GH had no effect on the net amino acid uptake but stimulated amino acid incorporation into protein, although this response was less in LP animals than in control animals.3. In muscle from PF animals, GH stimulated both amino acid incorporation into protein and the net amino acid uptake, a type of response which also occurs in hypophysectomized animals. The magnitude of the effect of GH on the incorporation of amino acids into protein was reduced in muscle from PF animals.4. The effect of GH on the net amino acid uptake in PF animals was completely blocked by cycloheximide; the uptake effect of GH in these animals was dependent therefore on de novo protein synthesis.5. It is proposed that in the adult the role of growth hormone in protein metabolism is to sustain cellular protein synthesis when there is a decrease in the level of substrate amino acids, similar to that which occurs during a short-term fast or when the dietary protein intake is inadequate.

scholarly journals Rationally Design of a Proline Transporter Inhibitor with Anti-Trypanosoma Cruzi Activity

2019 ◽  
Author(s):  
Lucia Fargnoli ◽  
Esteban A. Panozzo-Zénere ◽  
Lucas Pagura ◽  
María Julia Barisón ◽  
Julia A. Cricco ◽  
...  
Keyword(s):  
Amino Acid ◽  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Variable Region ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Cell Infection ◽  
Atp Production ◽  
First Case

L-Proline is an important amino acid for the pathogenic protists belonging to <i>Trypanosoma</i> and <i>Leishmania </i>genera. In <i>Trypanosoma cruzi</i>, the etiological agent of Chagas disease, this amino acid is involved in fundamental biological processes such as ATP production, differentiation of the insect and intracellular stages, the host cell infection and the resistance to a variety of stresses, including nutritional and osmotic as well as oxidative imbalance. In this study, we explore the L-Proline uptake as a chemotherapeutic target for <i>T. cruzi</i>. For this, we propose a novel rational to design inhibitors containing this amino acid as a recognizable motif. This rational consists of conjugating the amino acid (proline in this case) to a linker and a variable region able to block the transporter. We obtained a series of sixteen 1,2,3-triazolyl-proline derivatives through alkylation and copper(I)-catalyzed azide-alkyne cycloaddition (click chemistry) for <i>in vitro</i> screening against <i>T. cruzi </i>epimastigotes, trypanocidal activity and proline uptake. We successfully obtained inhibitors that are able to interfere with the amino acid uptake, which validated the first example of a rationally designed chemotherapeutic agent targeting a metabolite's transport. Additionally, we designed and prepared fluorescent analogues of the inhibitors that were successfully taken up by <i>T. cruzi</i>, allowing following up their intracellular fate. In conclusion, we successfully designed and produced a series of metabolite uptake inhibitors. This is one of few examples of rationally designed amino acid transporter inhibitor, being the first case where the strategy is applied on the development of chemotherapy against Chagas disease. This unprecedented development is remarkable having in mind that only a small percent of the metabolite transporters has been studied at the structural and/or molecular level.

THE METABOLISM OF ANIMAL TISSUES CULTIVATED IN VITRO: II. AMINO ACID METABOLISM OF CHICK EMBRYONIC KIDNEY, CHICK EMBRYONIC LIVER, AND MONKEY KIDNEY CORTEX CULTURES

1958 ◽  
Vol 36 (1) ◽  
pp. 171-184 ◽  
Author(s):  
Arthur E. Pasieka ◽  
Helen J. Morton ◽  
Joseph F. Morgan
Keyword(s):  
Tissue Culture ◽  
Amino Acid ◽  
Culture Medium ◽  
Synthetic Medium ◽  
Amino Acid Uptake ◽  
Monkey Kidney ◽  
Kidney Cortex ◽  
Acid Uptake ◽  
Embryonic Liver

Freshly-explanted chick embryonic kidney, chick embryonic liver, and trypsinized monkey kidney cortex cells have been cultivated in vitro in completely synthetic medium M 150. The amino acid changes in the nutrient medium during cultivation of these tissues have been studied by paper chromatography. A characteristic pattern of amino acid uptake and accumulation in the used culture medium has been demonstrated with each type of tissue culture. It has also been shown that, while the amino acid changes in the medium are different with each type of tissue culture, all cultures examined removed adenine from the medium and liberated small amounts of material thought to be hypoxanthine.

scholarly journals Angiotensin II inhibits NaCl absorption in the rat medullary thick ascending limb

2004 ◽  
Vol 287 (3) ◽  
pp. F404-F410 ◽  
Author(s):  
Nicolas Lerolle ◽  
Soline Bourgeois ◽  
Françoise Leviel ◽  
Gaëtan Lebrun ◽  
Michel Paillard ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Plasma Membranes ◽  
Inhibitory Effect ◽  
Thick Ascending Limb ◽  
Sprague Dawley ◽  
Experimental Conditions ◽  
Nacl Absorption ◽  
Medullary Thick Ascending Limb

NaCl reabsorption in the medullary thick ascending limb of Henle (MTALH) contributes to NaCl balance and is also responsible for the creation of medullary interstitial hypertonicity. Despite the presence of angiotensin II subtype 1 (AT1) receptors in both the luminal and the basolateral plasma membranes of MTALH cells, no information is available on the effect of angiotensin II on NaCl reabsorption in MTALH and, furthermore, on angiotensin II-dependent medullary interstitial osmolality. MTALHs from male Sprague-Dawley rats were isolated and microperfused in vitro; transepithelial net chloride absorption ( JCl) as well as transepithelial voltage ( Vte) were measured. Luminal or peritubular 10−11 and 10−10 M angiotensin II had no effect on JCl or Vte. However, 10−8 M luminal or peritubular angiotensin II reversibly decreased both JCl and Vte. The effect of both luminal and peritubular angiotensin II was prevented by the presence of losartan (10−6 M). By contrast, PD-23319, an AT2-receptor antagonist, did not alter the inhibitory effect of 10−8 M angiotensin II. Finally, no additive effect of luminal and peritubular angiotensin II was observed. We conclude that both luminal and peritubular angiotensin II inhibit NaCl absorption in the MTALH via AT1 receptors. Because of intrarenal angiotensin II synthesis, angiotensin II concentration in medullary tubular and interstitial fluids may be similar in vivo to the concentration that displays an inhibitory effect on NaCl reabsorption under the present experimental conditions.

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