Insulin Antagonistic Effect of Human Plasma Albumin on Protein Synthesis in vitro and on Glycogen Synthesis in vivo in the Rat Diaphragm Muscle

1966 ◽  
Vol 66 (3) ◽  
pp. 300-306 ◽  
Author(s):  
Jak Jervell
Keyword(s):  
Protein Synthesis ◽  
Human Plasma ◽  
Glycogen Synthesis ◽  
Antagonistic Effect ◽  
Diaphragm Muscle ◽  
Rat Diaphragm ◽  
Plasma Albumin

Reversal of the exercise-induced increase in muscle permeability to glucose

1987 ◽  
Vol 253 (4) ◽  
pp. E331-E335 ◽  
Author(s):  
D. A. Young ◽  
H. Wallberg-Henriksson ◽  
M. D. Sleeper ◽  
J. O. Holloszy
Keyword(s):  
Protein Synthesis ◽  
Glucose Transport ◽  
Glycogen Synthesis ◽  
Carbohydrate Restriction ◽  
Rat Serum ◽  
Low Concentration ◽  
Carbohydrate Feeding ◽  
Exercise Induced

Exercise is associated with an increase in permeability of muscle to glucose that reverses slowly (h) in fasting rats during recovery. Previous studies showed that carbohydrate feeding speeds and carbohydrate restriction slows reversal of the exercise-induced increase in glucose uptake. This study was designed to evaluate the roles of glucose transport, glycogen synthesis, and protein synthesis in the reversal process in rat epitrochlearis muscle. In contrast to recovery in vivo, when muscles were incubated without insulin in vitro, the exercise-induced increase in muscle permeability to sugar reversed rapidly regardless of whether glucose transport or glycogen synthesis occurred. Inhibition of protein synthesis did not prevent the reversal. Addition of 33% rat serum or a low concentration of insulin to the incubation medium markedly slowed reversal in vitro. We conclude that 1) prolonged persistence of the increased permeability of mammalian muscle to glucose after exercise requires a low concentration of insulin, and 2) reversal of the increase in permeability does not require glucose transport, glycogen synthesis, or protein synthesis.

THE WATER AND ELECTROLYTE METABOLISM OF RAT DIAPHRAGM IN VITRO

1956 ◽  
Vol 34 (1) ◽  
pp. 1069-1083 ◽  
Author(s):  
R. H. Rixon ◽  
J. A. F. Stevenson
Keyword(s):  
Intracellular Water ◽  
Diaphragm Muscle ◽  
Optimal Conditions ◽  
Rat Diaphragm ◽  
Concentration Gradients ◽  
Hypoxic Conditions ◽  
Diaphragm In Vitro ◽  
Sodium And Potassium

The distribution of water and of sodium and potassium between the cell and synthetic environments has been studied in rat diaphragm muscle. It has been found that: (1) the amount of intracellular water is markedly increased at 0 °C. in oxygen and at 37 °C. in nitrogen compared to that of tissue at 37 °C. in oxygen, in media up to 0.75 osmolar; (2) optimal conditions of temperature and oxygen are necessary to prevent or reduce the uptake of water; (3) swelling at reduced temperatures and under hypoxic conditions is related to the oxygen uptake; (4) the loss of tissue solids during incubation does not have any significant effect on the calculation of the total tissue and intracellular water; (5) the concentration of total sodium and potassium in the tissue, in vivo and in vitro at optimal conditions is slightly in excess of that in the plasma water or incubating medium—this is believed not to represent an active hypertonicity; (6) concomitant with the uptake of water there are marked redistributions of sodium and potassium, the gain of sodium being greater than the loss of potassium. It is concluded that the swelling of tissue cells under conditions that inhibit oxidative metabolism is primarily due to the redistribution of electrolytes and that the natural distribution of water in muscle is determined by active maintenance of the concentration gradients of sodium and potassium across the cell membrane.

Using 2H2O to study the influence of feeding on protein synthesis: effect of isotope equilibration in vivo vs. in cell culture

2005 ◽  
Vol 288 (6) ◽  
pp. E1277-E1283 ◽  
Author(s):  
Danielle A. Dufner ◽  
Ilya R. Bederman ◽  
Daniel Z. Brunengraber ◽  
Nadia Rachdaoui ◽  
Faramarz Ismail-Beigi ◽  
...  
Keyword(s):  
Cell Culture ◽  
Protein Synthesis ◽  
Steady State ◽  
Culture Medium ◽  
Body Water ◽  
Cell Culture Medium ◽  
Plasma Albumin ◽  
Single Meal

We previously reported that 2H2O can be used to measure rates of protein synthesis during prolonged steady-state conditions (Previs SF, Fatica R, Chandramouli V, Alexander JC, Brunengraber H, and Landau BR. Am J Physiol Endocrinol Metab 286: E665-E672, 2004). The underlying premise of our method is that following the administration of 2H2O, 2H atoms in body water rapidly equilibrate with free alanine before it is incorporated into newly synthesized proteins. We have now directly examined whether 2H2O can be used to measure the influence of a single meal on protein synthesis. In addition, we have compared the use of 2H2O for measuring rates of protein synthesis in vivo vs. in cell culture. Using a rat model, we observed rapid equilibration between 2H in body water and free alanine; therefore we were able to study the response of protein synthesis to a single meal. We observed that ∼50% of the plasma albumin that is synthesized over the course of 24 h is made within ∼5 h after eating (in rats trained to eat a complete 24-h ration of food in a single meal). Contrary to what we observed in vivo, feeding (the replenishment of cell culture medium) does influence the use of 2H2O for in vitro studies. In particular, since there can be slow equilibration of 2H between water and alanine in the cell culture medium, special consideration must be made to avoid underestimating the rate of protein synthesis in vitro.

THE WATER AND ELECTROLYTE METABOLISM OF RAT DIAPHRAGM IN VITRO

1956 ◽  
Vol 34 (5) ◽  
pp. 1069-1083 ◽  
Author(s):  
R. H. Rixon ◽  
J. A. F. Stevenson
Keyword(s):  
Intracellular Water ◽  
Diaphragm Muscle ◽  
Optimal Conditions ◽  
Rat Diaphragm ◽  
Concentration Gradients ◽  
Hypoxic Conditions ◽  
Diaphragm In Vitro ◽  
Sodium And Potassium

The distribution of water and of sodium and potassium between the cell and synthetic environments has been studied in rat diaphragm muscle. It has been found that: (1) the amount of intracellular water is markedly increased at 0 °C. in oxygen and at 37 °C. in nitrogen compared to that of tissue at 37 °C. in oxygen, in media up to 0.75 osmolar; (2) optimal conditions of temperature and oxygen are necessary to prevent or reduce the uptake of water; (3) swelling at reduced temperatures and under hypoxic conditions is related to the oxygen uptake; (4) the loss of tissue solids during incubation does not have any significant effect on the calculation of the total tissue and intracellular water; (5) the concentration of total sodium and potassium in the tissue, in vivo and in vitro at optimal conditions is slightly in excess of that in the plasma water or incubating medium—this is believed not to represent an active hypertonicity; (6) concomitant with the uptake of water there are marked redistributions of sodium and potassium, the gain of sodium being greater than the loss of potassium. It is concluded that the swelling of tissue cells under conditions that inhibit oxidative metabolism is primarily due to the redistribution of electrolytes and that the natural distribution of water in muscle is determined by active maintenance of the concentration gradients of sodium and potassium across the cell membrane.

scholarly journals A comparison of rates of protein turnover in rat diaphragm in vivo and in vitro

1986 ◽  
Vol 233 (1) ◽  
pp. 279-282 ◽  
Author(s):  
V R Preedy ◽  
D M Smith ◽  
P H Sugden
Keyword(s):  
Protein Synthesis ◽  
Protein Turnover ◽  
Rat Diaphragm ◽  
Degradation Rates ◽  
Protein Synthesis And Degradation ◽  
Synthesis And Degradation

Protein synthesis and degradation rates in diaphragms from fed or starved rats were compared in vivo and in vitro. For fed rats, synthesis rates in vivo were approximately twice those in vitro, but for starved rats rates were similar. Degradation rates were less in vivo than in vitro in diaphragms from either fed or starved rats.

Glucose uptake and glycogen synthesis in normal and chronically active muscles

1993 ◽  
Vol 264 (3) ◽  
pp. E328-E333
Author(s):  
R. J. Talmadge ◽  
H. Silverman
Keyword(s):  
Glucose Uptake ◽  
Contractile Activity ◽  
Glycogen Synthesis ◽  
Diaphragm Muscle ◽  
In Vivo Experiments ◽  
Hindlimb Muscles ◽  
Increased Sensitivity ◽  
And Control

The hindlimb muscles of the C57Bl6J dy2J/dy2J (dy2J) mouse suffer from a chronic neural stimulation (pseudomyotonia), resulting in increased contractile activity. In response to the increased contractile activity, these muscles store increased amounts of glycogen. In this study, glucose uptake and glycogenesis (glycogen synthesis from glucose) were analyzed in chronically active and normal muscles. In vivo experiments demonstrate increased 3-O-methylglucose (3-MG) uptake rates and glycogenesis by chronically active dy2J gastrocnemius muscles (Gast) vs. normal control Gast. The chronically active diaphragm muscle (Dia) showed the highest rates of 3-MG uptake, as well as glycogenesis in vivo when compared with other skeletal muscles. No differences were observed between dy2J and control Dia. The levels of blood glucose were similar between dy2J and control animals. In vitro experiments demonstrated an increased sensitivity and responsiveness to insulin for glucose uptake in the dy2J soleus muscle (Sol). Glycogenesis by dy2J Sol was elevated only at the highest insulin concentration tested (10,000 microU/ml). In contrast, the dy2J extensor digitorum longus muscle had an increased sensitivity and responsiveness to insulin for both glucose uptake and glycogenesis. This study demonstrates that chronically active muscles have elevated capacities for glucose uptake and glycogenesis and may help to explain the elevated glycogen levels in the dy2J hindlimb muscles.

scholarly journals Comparison of some metabolic parameters in the perfused and the incubated rat diaphragm muscle with diaphragm muscle in vivo

1971 ◽  
Vol 125 (1) ◽  
pp. 93-96 ◽  
Author(s):  
K. A. Rookledge
Keyword(s):  
Oxidative Phosphorylation ◽  
Water Content ◽  
Lactate Production ◽  
Metabolic Parameters ◽  
Diaphragm Muscle ◽  
Rat Diaphragm ◽  
Free Glucose ◽  
Hexose Phosphates

1. A method is described for perfusing the rat diaphragm muscle. 2. The following parameters were compared in both perfused and non-perfused incubated preparations: water content, sorbitol space, rate of lactate production, and the concentrations of tissue glucose, pyruvate, lactate, hexose phosphate intermediates, ATP and AMP. No significant differences were found. 3. Significant differences, however, were found on comparison of the tissue kept in vitro with the tissue in vivo. Immediately after removal of the tissue from the animal, the concentrations of the hexose phosphates and ATP were found to be much higher than after incubation or perfusion, and the concentrations of free glucose and of AMP were much lower, possibly indicating that the capacity for oxidative phosphorylation of glucose is impaired in vitro because of hypoxia.

EFFECT OF TESTOSTERONE ON PROTEIN SYNTHESIS AND CONTRACTILITY OF THE LEVATOR ANI MUSCLE OF THE RAT

1971 ◽  
Vol 50 (4) ◽  
pp. 643-651 ◽  
Author(s):  
M. BUREŠOVÁ ◽  
E. GUTMANN
Keyword(s):  
Protein Synthesis ◽  
Latency Period ◽  
Previous Treatment ◽  
Levator Ani ◽  
Diaphragm Muscle ◽  
Levator Ani Muscle ◽  
Contraction Time

SUMMARY The effects of testosterone on the incorporation of leucine and uridine into the proteins and RNA in vitro and on contractile properties of the levator ani muscle were studied. After long-term preincubation of the muscle with testosterone, incorporation of the labelled precursors into RNA and proteins of the muscle increased by 33 and 78% respectively. No previous treatment in vivo was necessary to show this effect of testosterone. The increase of incorporation of the labelled precursors into RNA and proteins, tested after preincubation with testosterone, was more pronounced after castration, and was 61 and 134% respectively. The incorporation of labelled precursors into RNA and proteins of the diaphragm muscle of the rat was not affected by preincubation with testosterone in vitro. Long-term application of testosterone in vitro resulted in a decrease of contraction time and latency period of the levator ani muscle.

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