Induction of an intestinal epithelial sugar transport system by high blood sugar

1977 ◽  
Vol 33 (2) ◽  
pp. 223-224 ◽  
Author(s):  
T. Z. Csáky ◽  
E. Fischer
Keyword(s):  
Blood Sugar ◽  
Transport System ◽  
Sugar Transport ◽  
Intestinal Epithelial ◽  
High Blood Sugar

Effects of phloretin and theophylline on 3-O-methylglucose transport by intestinal epithelial cells

1978 ◽  
Vol 234 (3) ◽  
pp. C64-C72 ◽  
Author(s):  
J. Randles ◽  
G. A. Kimmich
Keyword(s):  
Epithelial Cells ◽  
Transport System ◽  
Intestinal Epithelial Cells ◽  
Sugar Transport ◽  
Inhibitory Effect ◽  
Metabolic Effects ◽  
Transport Systems ◽  
Facilitated Diffusion ◽  
Intestinal Epithelial ◽  
Gradient Enhancement

Phloretin and theophylline each exert an immediate inhibitory effect on the Na+-independent, facilitated-diffusion transport system for sugar associated with intestinal epithelial cells. Phloretin inhibits approximately 50% more of the total Na+-independent sugar flux than theophylline. Neither agent has an immediate effect on the Na+-dependent, concentrative sugar transport system, although preincubation of the cells with phloretin causes a significant inhibition. The slowly developing effect is correlated with a decrease in cellular adenosine triphosphate (ATP) and an elevation of intracellular Na+. Other agents which elevate cell Na+ also inhibit Na+-dependent sugar influx, even if ATP levels are not depleted. On the other hand, if ATP is depleted by phloretin under conditions in which the cells do not gain Na+, the inhibitory effect on Na+-dependent sugar flux tends to disappear. The slow-onset phloretin effects are due to transinhibition of the Na+-dependent sugar carrier by cellular Na+. When the passive sugar carrier is inhibited by phloretin or theophylline, the concentrative system can establish an enhanced sugar gradient. Because of the secondary metabolic effects of phloretin, theophylline induces a greater gradient enhancement despite its more limited effect on the passive sugar-transport system. Sugar gradients as large as 20-fold are induced by theophylline, in contrast to 12-fold gradients observed in the presence of phloretin and approximately 7- to 8-fold for untreated cells. These results are discussed in terms of conceptual questions regarding the energetics of Na+-dependent transport systems.

scholarly journals Evidence for two asymmetric conformational states in the human erythrocyte sugar-transport system

1975 ◽  
Vol 145 (3) ◽  
pp. 417-429 ◽  
Author(s):  
J E Barnett ◽  
G D Holman ◽  
R A Chalkley ◽  
K A Munday
Keyword(s):  
Glucose Transport ◽  
Transport System ◽  
Human Erythrocyte ◽  
Partition Coefficients ◽  
External Medium ◽  
Sugar Transport ◽  
Conformational States ◽  
Glucose Transport System ◽  
Oil Water

6-O-methyl-, 6-O-propyl-, 6-O-pentyl- and 6-O-benzyl-D-galactose, and 6-O-methyl-, 6-O-propyl- and 6-O-pentyl-D-glucose inhibit the glucose-transport system of the human erythrocyte when added to the external medium. Penetration of 6-O-methyl-D-galactose is inhibited by D-glucose, suggesting that it is transported by the glucose-transport system, but the longer-chain 6-O-alkyl-D-galactoses penetrate by a slower D-glucose-insensitive route at rates proportional to their olive oil/water partition coefficients. 6-O-n-Propyl-D-glucose and 6-O-n-propyl-D-galactose do not significantly inhibit L-sorbose entry or D-glucose exit when present only on the inside of the cells whereas propyl-beta-D-glucopyranoside, which also penetrates the membrane slowly by a glucose-insensitive route, only inhibits L-sorbose entry or D-glucose exit when present inside the cells, and not when on the outside. The 6-O-alkyl-D-galactoses, like the other nontransported C-4 and C-6 derivatives, maltose and 4,6-O-ethylidene-D-glucose, protect against fluorodinitrobenzene inactivation, whereas propyl beta-D-glucopyranoside stimulates the inactivation. Of the transported sugars tested, those modified at C-1, C-2 and C-3 enhance fluorodinitrobenzene inactivation, where those modified at C-4 and C-6 do not, but are inert or protect against inactivation. An asymmetric mechanism is proposed with two conformational states in which the sugar binds to the transport system so that C-4 and C-6 are in contact with the solvent on the outside and C-1 is in contact with the solvent on the inside of the cell. It is suggested that fluorodinitrobenzene reacts with the form of the transport system that binds sugars at the inner side of the membrane. An Appendix describes the theoretical basis of the experimental methods used for the determination of kinetic constants for non-permeating inhibitors.

scholarly journals THE HYPOPHYSIS AND SECRETION OF INSULIN

1942 ◽  
Vol 75 (5) ◽  
pp. 547-566 ◽  
Author(s):  
B. A. Houssay ◽  
V. G. Foglia ◽  
F. S. Smyth ◽  
C. T. Rietti ◽  
A. B. Houssay
Keyword(s):  
Insulin Secretion ◽  
B Cells ◽  
Blood Sugar ◽  
Anterior Pituitary ◽  
Blood Sugar Level ◽  
Pituitary Hormone ◽  
Pituitary Extract ◽  
Histological Changes ◽  
High Blood Sugar ◽  
Anterior Pituitary Hormone

The ability of the pancreas, from various types of dogs, to correct diabetic hyperglycemia has been studied (Table XI). The pancreas from one animal was united by a vascular union with the neck blood vessels of another dog which had been pancreatectomized for 20 hours. The time necessary to reduce the blood sugar level to 120 mg. per cent was determined. 1. Pancreas from 6 hypophysectomized dogs produced a normal insulin secretion, showing that an anterior pituitary hormone is not necessary for its production or maintenance. 2. In 14 of 17 normal dogs given anterior pituitary extract for 3 or more consecutive days and presenting diabetes (fasting blood sugar 150 mg. per cent or more) the pancreas showed diminished insulin production. 3. In animals which remained diabetic after discontinuing the injections of hypophyseal extract, the pancreas islands were markedly pathologic and the insulin secretion was practically nil. 4. When hyperglycemia existed on the 2nd to 5th day but fell later, the insulin secretion of 5 dogs was normal in 2, supernormal in 1, and less than normal in 2. Histologic examination showed a restoration of beta cells. 5. In 14 dogs resistant to the diabetogenic action of anterior pituitary extract, as shown by little or no change in blood sugar, the pancreatic secretion of insulin was normal in 6 cases, supernormal in 3, and subnormal in 5 cases. Clear signs of hyperfunction of B cells were observed. In 6 resistant animals a high blood sugar (150 mg. per cent) appeared shortly before transplanting, but insulin secretion was normal in 4, supernormal in 1, and subnormal in 1 case. 6. With one injection of extract and 1 day of hyperglycemia the capacity of the pancreas to secrete insulin was not altered. 7. A high blood sugar level lasting 4 days does not alter the islets. The hypophyseal extract acts, therefore, by some other mechanism. In normal dogs, the continuous intravenous infusion of glucose for 4 days maintained the blood sugar at levels as high as those after pituitary extract. In these animals the B cells were hyperplastic and insulin secretion normal. 8. Anterior hypophyseal hyperglycemia is due at first to extrapancreatic factors which are the most important, and last only during the injections of extracts. Pancreatic factors appear afterwards and are responsible for permanent diabetes. Hypophyseal extract produces histological changes in many tissues and damages the Langerhans islands. The coexistent high blood sugar probably exhausts the B cells and exaggerates their injury. 9. In all cases there is a relation between the cytology of the islet B cells and the insulin secreting capacity.

scholarly journals A MODERN OVERVIEW ON DIABETES MELLITUS: A CHRONIC ENDOCRINE DISORDER

2020 ◽  
Vol 5 (2) ◽  
pp. 1-14
Author(s):  
Y Mukhtar ◽  
A Galalain ◽  
U Yunusa
Keyword(s):  
Diabetes Mellitus ◽  
Blood Sugar ◽  
Insulin Dependent Diabetes Mellitus ◽  
Insulin Dependent Diabetes ◽  
Hypoglycemic Agents ◽  
Dependent Diabetes Mellitus ◽  
High Blood Sugar ◽  
Type 2 Dm ◽  
Insulin Dependent

Diabetes mellitus is one of the most common endocrine disorders that affect the body’s ability to make or use insulin. Diabetes mellitus (DM), or simply diabetes, is a group of chronic metabolic diseases in which a person experience high blood sugar, either because the pancreas does not produce enough insulin or because the body cells do not effectively use or respond to the insulin that is produced. This high blood sugar produces the classical symptoms of polyuria (frequent urination), polydipsia (increased thirst) and polyphagia (increased hunger). Conventionally, diabetes has been divided into three types namely: Type 1 DM or insulin-dependent diabetes mellitus (IDDM) in which body fails to produce insulin, and presently requires the person to inject insulin or wear an insulin pump. This is also termed as "juvenile diabetes". Type 2 DM or non-insulin-dependent diabetes mellitus (NIDDM), results from insulin resistance, a condition in which cells fail to use insulin properly, with or without an absolute insulin deficiency. This type was previously referred to as or "adult-onset diabetes". The third main type is gestational diabetes which occurs when women without a previous history of diabetes develop a high blood glucose level during her pregnancy and may metamorphose to type 2 DM after giving birth. Currently available pharmacotherapy for the treatment of diabetes mellitus includes insulin and oral hypoglycemic agents. Thus, the present review underscores the issues surrounding the symptoms, diagnosis and treatment (especially use of anti-diabetic herbal species) of this killer disease with a view to suppressing its global spread and resurgence.

scholarly journals Fasdhu therapy to reduce excess levels of substances in the human body

2021 ◽  
Vol 6 (7) ◽  
pp. 1276-1281
Author(s):  
Darmadi Darmadi ◽  
Siti Juariah ◽  
Sukri Sukri
Keyword(s):  
Uric Acid ◽  
Health Education ◽  
Blood Sugar ◽  
Body Fat ◽  
Human Body ◽  
High Blood Sugar ◽  
The People ◽  
Sugar Levels ◽  
Provide Health Education

Tarai Bangun Hamlet IV, Tarab Mulya Village is a village located in Kampar Regency where the majority of the people come from the Minang and Javanese tribes. They like to eat fatty foods that trigger an increase in body fat levels. This service is carried out with the aim of helping people who experience high blood sugar, cholesterol and uric acid levels with the phlebotomy technique (fasdhu). The method used is to provide health education, followed by checking blood sugar, cholesterol and uric acid. High levels are then performed Fasdhu. Based on the examination of blood sugar, cholesterol and uric acid checks on 37 respondents, it was found that 10 respondents had high levels. Fasdhu treatment was carried out on respondents who had blood sugar levels of 163 mg/dl, cholesterol 240.75 mg/dl and uric acid 8.95 mg/dl. After fasdhu treatment, the levels decreased to 107 mg/dl, 200 mg/dl and 7.15 mg/dl, respectively. Based on this treatment, it was concluded that the phlebotomy technique (fasdhu) could be recommended as an effort to reduce blood sugar, cholesterol and uric acid levels.

scholarly journals The Glucuronic Acid Utilization Gene Cluster from Bacillus stearothermophilus T-6

1999 ◽  
Vol 181 (12) ◽  
pp. 3695-3704 ◽  
Author(s):  
Smadar Shulami ◽  
Orit Gat ◽  
Abraham L. Sonenshein ◽  
Yuval Shoham
Keyword(s):  
Gene Cluster ◽  
Transport System ◽  
Bacillus Stearothermophilus ◽  
Glucuronic Acid ◽  
Genomic Library ◽  
Regulatory Gene ◽  
Sugar Transport ◽  
Transcriptional Unit ◽  
Transport Systems ◽  
Potential Operator

ABSTRACT A λ-EMBL3 genomic library of Bacillus stearothermophilus T-6 was screened for hemicellulolytic activities, and five independent clones exhibiting β-xylosidase activity were isolated. The clones overlap each other and together represent a 23.5-kb chromosomal segment. The segment contains a cluster of xylan utilization genes, which are organized in at least three transcriptional units. These include the gene for the extracellular xylanase, xylanase T-6; part of an operon coding for an intracellular xylanase and a β-xylosidase; and a putative 15.5-kb-long transcriptional unit, consisting of 12 genes involved in the utilization of α-d-glucuronic acid (GlcUA). The first four genes in the potential GlcUA operon (orf1, -2, -3, and -4) code for a putative sugar transport system with characteristic components of the binding-protein-dependent transport systems. The most likely natural substrate for this transport system is aldotetraouronic acid [2-O-α-(4-O-methyl-α-d-glucuronosyl)-xylotriose] (MeGlcUAXyl3). The following two genes code for an intracellular α-glucuronidase (aguA) and a β-xylosidase (xynB). Five more genes (kdgK,kdgA, uxaC, uxuA, anduxuB) encode proteins that are homologous to enzymes involved in galacturonate and glucuronate catabolism. The gene cluster also includes a potential regulatory gene, uxuR, the product of which resembles repressors of the GntR family. The apparent transcriptional start point of the cluster was determined by primer extension analysis and is located 349 bp from the initial ATG codon. The potential operator site is a perfect 12-bp inverted repeat located downstream from the promoter between nucleotides +170 and +181. Gel retardation assays indicated that UxuR binds specifically to this sequence and that this binding is efficiently prevented in vitro by MeGlcUAXyl3, the most likely molecular inducer.

Sodium-dependent succinate transport by isolated chick intestinal cells

1991 ◽  
Vol 260 (6) ◽  
pp. C1151-C1157 ◽  
Author(s):  
G. A. Kimmich ◽  
J. Randles ◽  
E. Bennett
Keyword(s):  
Transport System ◽  
Renal Tissue ◽  
Transport Rate ◽  
Hill Coefficient ◽  
Intestinal Epithelial ◽  
Coupled Transport ◽  
Renal Epithelium ◽  
Metabolic Intermediates ◽  
Hill Coefficients ◽  
The Hill

Isolated chick intestinal epithelial cells take up succinate by a Na(+)-coupled transport system similar in some characteristics to those described for renal epithelium. The transport system exhibits a hyperbolic dependence on succinate concentration but a sigmoidal dependence on Na+ concentration. Best nonlinear fit of the Na+ dependence data to the Hill equation indicates a Michaelis constant for half-maximal transport rate (Km) for Na+ of approximately 20 mM, a maximal transport rate (Vmax) of 1.1 nmol succinate.min-1.mg protein-1, and a Hill coefficient of 2.5. Nearly equivalent fit was obtained with trial Hill coefficients down to 2.0. The data for succinate dependence indicated a Km of 25 microM and Vmax of 1.05 nmol.min-1.mg protein-1. The kinetic parameters indicate a higher affinity, lower capacity system than for succinate transport in the renal brush-border system. Thiocyanate-induced diffusion potentials cause no change in Na(+)-dependent succinate influx despite pronounced effects on the influx of tetraphenylphosphonium and on Na(+)-dependent alpha-methylglucoside (AMG) and alanine uptake. Several other dicarboxylic and tricarboxylic metabolic intermediates (but not the dicarboxylic amino acids) compete with succinate for uptake via the transport system. The data are consistent with the likelihood that these cells have a succinate transport system with a 2Na+:1succinate stoichiometry per transport cycle. The system catalyzes no net charge transfer and is therefore different from the potential-responsive succinate transporter described for renal tissue.

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