scholarly journals Location of 14C in protein from isolated rat diaphragm incubated in vitro with [14C]amino acids and with 14CO2

1959 ◽  
Vol 72 (1) ◽  
pp. 136-141 ◽  
Author(s):  
K L Manchester ◽  
F. G. Young
Keyword(s):  
Amino Acids ◽  
Rat Diaphragm ◽  
Isolated Rat

THE EFFECT OF GROWTH HORMONE AND OF CORTISOL ON THE RESPONSE OF ISOLATED RAT DIAPHRAGM TO THE STIMULATING EFFECT OF INSULIN ON GLUCOSE UPTAKE AND ON INCORPORATION OF AMINO ACIDS INTO PROTEIN

1959 ◽  
Vol 18 (4) ◽  
pp. 395-408 ◽  
Author(s):  
K. L. MANCHESTER ◽  
P. J. RANDLE ◽  
F. G. YOUNG
Keyword(s):  
Amino Acids ◽  
Growth Hormone ◽  
Protein Synthesis ◽  
Glucose Uptake ◽  
Carbohydrate Metabolism ◽  
Rat Diaphragm ◽  
Pituitary Growth Hormone ◽  
Isolated Rat ◽  
Stimulation Of

SUMMARY 1. The effect of hypophysectomy, or of adrenalectomy, and injection of pituitary growth hormone (GH) or of cortisol, on the uptake of glucose and the incorporation of glycine into protein by isolated rat diaphragm, and the effect of the addition of insulin in vitro on these processes, has been studied. 2. Both hypophysectomy and adrenalectomy raised the uptake of glucose by isolated diaphragm, while treatment of the intact or of the hypophysectomized rat with GH, or of the intact or of the adrenalectomized rat with cortisol, depressed it. Although hypophysectomy and adrenalectomy did not influence the additional glucose uptake induced by 200 mu./ml. of insulin in vitro, both these operations enhanced the effect of 0·1–1·0 mu./ml. of insulin on glucose uptake by diaphragm in vitro. Treatment of the rat with GH or cortisol diminished the rise in glucose uptake of diaphragm induced by 0·1–1·0 mu./ml. insulin. 3. Hypophysectomy depressed, and administration of GH to the intact or hypophysectomized rat raised, the incorporation of glycine into protein of the isolated diaphragm, but neither of these operations altered the magnitude of the stimulation of incorporation induced by 1·0 mu./ml. insulin. 4. Adrenalectomy raised, and administration of cortisol to the intact or adrenalectomized rat depressed, the incorporation of glycine into protein of the isolated diaphragm; adrenalectomy enhanced, the injection of cortisol diminished, the effect of 1·0 mu./ml. insulin on these processes. 5. The possibility that GH directs insulin towards the stimulation of protein synthesis, in part by restraining the action of insulin on carbohydrate metabolism, is discussed.

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.

SENSITIVITY OF THE RAT DIAPHRAGM TO GROWTH HORMONE.

1967 ◽  
Vol 54 (4) ◽  
pp. 645-662 ◽  
Author(s):  
Å. Hjalmarson ◽  
K. Ahrén
Keyword(s):  
Growth Hormone ◽  
Inhibitory Effect ◽  
Rat Diaphragm ◽  
Intracellular Accumulation ◽  
Slight Effect ◽  
Kidney Capsule ◽  
Muscle Tissues ◽  
Hypophysectomized Rats ◽  
Isolated Rat

ABSTRACT The effect of growth hormone (GH) in vitro on the rate of intracellular accumulation of the non-utilizable amino acid α-aminoisobutyric acid (AIB) was studied in the intact rat diaphragm preparation. Bovine or ovine GH (25 μg/ml incubation medium) markedly stimulated the accumulation of AIB-14C by diaphragms from hypophysectomized rats, while there was no or only a very slight effect on diaphragms from normal rats. In diaphragms from rats with the pituitary gland autotransplanted to the kidney capsule GH in vitro stimulated the accumulation of AIB-14C significantly more than in diaphragms from normal rats but significantly less than in diaphragms from hypophysectomized rats. Injections of GH intramuscularly for 4 days to hypophysectomized rats made the diaphragms from these rats less sensitive or completely insensitive to GH in vitro. These results indicate strongly that the relative insensitivity to GH in vitro of diaphragms from normal rats is due to the fact that the muscle tissues from these rats has been exposed to the endogenously secreted GH. The results show that GH can influence the accumulation of AIB-14C in the isolated rat diaphragm in two different ways giving an acute or »stimulatory« effect and a late or »inhibitory« effect, and that it seems to be a time-relationship between these two effects of the hormone.

Insulin and incorporation of radioactivity into nucleic acid fraction of isolated diaphragm

1960 ◽  
Vol 199 (4) ◽  
pp. 719-721 ◽  
Author(s):  
Ira G. Wool
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acids ◽  
Glucose Concentration ◽  
Orotic Acid ◽  
Acid Fraction ◽  
Rat Diaphragm ◽  
Isolated Rat

Insulin in vitro stimulated the incorporation into the nucleic acid fraction of isolated rat diaphragm of radioactivity from d-glucose-U-C14, adenine-8-C14 and orotic acid-6-C14; insulin had no effect on the incorporation of thymine-2-C14 into muscle nucleic acids. Insulin enhanced the incorporation into nucleic acids of C14 from adenine and orotic acid in the absence of added glucose, and incorporation of adenine-8-C14 was not influenced by glucose concentration over the range 0–600 mg %.

Corticosteroids and incorporation of C14-phenylalanine into protein of isolated rat diaphragm

1960 ◽  
Vol 198 (5) ◽  
pp. 1111-1114 ◽  
Author(s):  
Ira G. Wool ◽  
Edward I. Weinshelbaum
Keyword(s):  
Potassium Concentration ◽  
Protein Biosynthesis ◽  
Fold Change ◽  
Prior Treatment ◽  
Rat Diaphragm ◽  
Phenylalanine Concentration ◽  
Intracellular Potassium ◽  
Intracellular Potassium Concentration ◽  
Isolated Rat

Prior treatment of rats with cortisone (2 mg/day) decreased l-phenylalanine-U-C14 incorporation into protein of isolated diaphragm. This action was not affected by a 100-fold change in the phenylalanine concentration, indicating that the steroid depresses protein biosynthesis in muscle. Hydrocortisone (50 µg/ml) added in vitro did not alter C14-phenylalanine incorporation. Large changes in intracellular potassium concentration were without influence on phenylalanine incorporation into protein of diaphragms from normal, adrenalectomized or cortisone-treated rats.

scholarly journals Albumin, fibrinogen and transferrin synthesis in isolated rat hepatocyte suspensions. A model for the study of plasma protein synthesis

1975 ◽  
Vol 146 (1) ◽  
pp. 141-155 ◽  
Author(s):  
K N Jeejeebhoy ◽  
J Ho ◽  
G R Greenberg ◽  
M J Phillips ◽  
A Bruce-Robertson ◽  
...  
Keyword(s):  
Amino Acids ◽  
Growth Hormone ◽  
Protein Synthesis ◽  
Plasma Protein ◽  
Plasma Proteins ◽  
Horse Serum ◽  
Rat Hepatocyte ◽  
Isolated Rat

A system using hepatocyte suspensions in vitro was developed for studying the synthesis of albumin, fibrinogen and transferrin. Conditions for optimum survival of the hepatocyte and for synthesis of these plasma proteins were defined for this system. These conditions included the use of horse serum (17.5 percent, v/v, heat-inactivated), an enriched medium (Waymouth's MB 752/1), an O2 tension of between 18.7 times 10(3) and 26.7 times 10(3) Pa and constant stirring. Albumin, fibrinogen and transferrin synthesis rates were obtained of 0.32 p 0.094(10), 0.12 p 0.030(11) and 0.097 p 0.017(10) [mean p S.D. (n)]mg/h per g of hepatocytes respectively. These rates were maintained for the first 12h of study and synthesis continued at a diminished rate up to 48h. The synthesis of albumin was decreased in a medium containing less amino acids and glucose, but that of fibrinogen was substantially unaffected. ATP concentrations up to 12h and RNA/DNA ratios up to 24h were comparable with values in vivo. The ability to study cells up to 48h permitted us to find that the addition of a mixture of hormones consisting of glucagon, cortisol, tri-iodothyronine and growth hormone enhanced fibrinogen synthesis. Addition of insulin to the above mixture resulted in increased synthesis for albumin and transferrin but not for fibrinogen.

In vitro Effect of Growth Hormone on the Glucose Uptake of Isolated Rat Diaphragm

Nature ◽  
1957 ◽  
Vol 179 (4557) ◽  
pp. 472-473 ◽  
Author(s):  
P. J. RANDLE ◽  
J. E. WHITNEY
Keyword(s):  
Growth Hormone ◽  
Glucose Uptake ◽  
Rat Diaphragm ◽  
Vitro Effect ◽  
Isolated Rat
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